Base-age
invariant polymorphic site curves
Robert L. Bailey
USDA,
Forest Serv.,So Forest Expt Stn, New Orleans, LA 70113
Jerome
L. Clutter.
Uinv Georgia, Dept Forest Resources & Statistics, Athens, GA 30601
Abstract
Polymorphic curves fitted by
techniques in which site index is a predictor variable are specific to a
preselected base age. A new approach eliminates this problem and the need to
quantify site quality with the data before estimating parameters.
Height-over-age curves for Pinu radiata D. Don in New Zealand are produced with
linear least-squares estimation . Bailey,
Clutter
Additional key words
Anamorphic curves, tree height, Pinus radiata
A compatible model
relating slash pine plantation survival to density, age, site
index, and type
and intensity of thinning
Robert L. Bailey
Bailey RL, Univ. Georgia, Sch Forest Resources,Athens,GA 30602
Bruce E. Borders
US Forest Serv., SE Forest Expt Stn, Macon, GA
Kenneth D. Ware
US Forest Serv.,SE Forest Expt Stn, Athens, GA
Earke P. Jones,Jr.
US Forest Serv.,SE Forest Expt Stn, Athens, GA
Abstract
Change in numbers of surviving trees in repeatedly thinned old-field slash pine
plantations was found to be significantly related to age, density, site index,
and level and type of thinning. A difference equation model was derived and
fitted with data from 824 growth periods from 289 manumented plots. This
difference equation formulation is a logical
extension of prior models to now
express the effects of type and level of thinning,
site index, and differential age effccts. It
is also compatible with other models required in a useful and
consistent growth and yield
prediction system for thinned stands. Thinning from below in young stands tended
to accelerate mortality; mortality rate
was directly related to site index. These facts are accounted for by the model. Bailey,
Borders
1985. For.
Sci. 31(1) :180-189.
Additional key words
Pinus elliolfii, difference equation model, growth predicting.
Aboveground Weight and Volume of
Unthinned, Planted
Longleaf Pine on
West Gulf Forest Sites.
V. Clark Baldwin,
US
Forest Serv, USDA, So Res Stn, 200 Weaver Blvd, Asheville, NC 28802 USA
Joseph R. Saucier
USDA,Forest
Serv., Forestry Sci., SE Forest Expt Stn, Carlton St, Athens, GA 30602
Abstract
Volume(
cubic foot) and weight predictions (green and dry) are presented in
equations and tables for aboveground total tree and tree components of
unthinned, planted longleaf pine trees. The 111 sample trees, from 10 stands in
Louisiana and Texas, were 10 to 44 years old and ranged from 1 to 21 inches dbh.
The data for saplings(dbh<5 inches) were analyzed separately from that of
commercial sized trees(dbh>5 inches). The
linearized allometric model utilizes the variable D^2H(squared diameter at
breast height multiplied by total tree height) the predict volumes and weights
of tree component in two size classes. Baldwin, Saucier
Estimation of total
yield of Douglas-fir by means of incomplete growth series
Jean Bégin
Univ Laval, Fac Foresterie & geomat, Quebec city G1K 7P4,PQ,Canada
Jean-Philippe Schütz
Eth Zentrum, Ecole Polytech Fed Zurich, CH-8092 Zurich, Swizerland
Summary
This study establishes
and validates a method that takes into account yield levels and permits the
reconstruction and modelling of the evolution of total yield based on incomplete
growth series. The calculation of total yield of Douglas fir (Pseudotsuga
menziesii (Mirb) Franco var menziesii Franco) is carried out by integrating the
equation of volume increment per metre dominant height growth. The model
utilized explains 94.8% of the variation in volume increment per metre height
growth of the 14 experimental plots. The evolution of total yield is calculated
for 4 current increment levels. The concept of current increment levels is
similar to the concept of yield levels, and corresponds to the value of volume
increment per metre height growth, at a height of 30
m. At an
equivalent yield level, the calculated total yield curves correspond closely to
those calculated by Bergel (1 985). Begin,
Schutz
Key words
total
yield , yield level , current increment level, volume Increment, Douglas fir
Improved estimates
of site-index curves using a varying-parameter model
Greg
S. Biging
Univ Calif. Berkley, Dept Forestry & Resource Management, Berkley, CA 94720,USA
Abstract
Current methods for developing site index curves from stem analysis data or from
remeasured permanent plots commonly regress height on
age (or age and site) using a
nonlinear regression model fitted to the pooled observations. While this is a
computationally efficient method, it does not satisfactorily account for
between-tree differences in individual tree height growth. This paper presents a
varying-parameter (linear random regression coefficient) model that is
derived by fitting height growth models to each individual tree in the
data set A
weighted least squares technique is
then employed to combine
thex individual estimates to f O R Ma mean estimate of
the parameters of a
sigmoid height growth model. These
parameters are then used to predict the height
development of site trees. An example
of the procedure is
given using stem analysis data
from primarily dominant trees in
the young-growth mixed conifer forests of California.
Additional key words
Stem
analysis data, sigmoid model, height growth.
Loblolly pine - pushing the limits of growth
Bruce E. Borders
Univ Georgia, Sch Forest Resources,Athens,GA 30602 USA
Robert L. Bailey
Univ Georgia, DB Warnell Sch Forest Resources, Athens, GA 30605 USA
Abstract
The
age of intensive plantation forestry in the Southeastern US rapidly approaches.
Based on data through age 9 from loblolly pine plantations subjected to complete
weed control and multiple fertilizations, growth rates to be expected equal or
exceed those for southern pines grown in other countries under intensive
cultural practices. Predictions of continuing growth through age 15 and
economical analyses indicate that these cultural practices will be excellent
financial investments for the owners of forest land. Borders,
Bailey 1997.
CAPPS:
Consortium on Accelerated Pine Production Studies Technical Report, CAPPS
1997-1. The University of Georgia, Cooperative Extension Service, Forest
Resources Publication.
N Carolina State Univ, Dept Forestry, Raleigh,
NC 27695
N Carolina State Univ, Ctr Comp Graph, Raleigh,NC 27695
Abstract
SPOT multispectral (XS) and Landsat Thematic Mapper (TM) digital data were studied in an attempt to evaluate the use of this data in detailed assessments of forest conditions. Forest type, basal area, and age class information were collected from 256 sample sites within an intensively managed 80 000 acre experimental forest in North Carolina, U.S.A. A comparison of the SPOT and TM data with the sample site information showed that XS3, the near-infrared waveband, and TM bands 2, 3, 4, 5, and 7 were significantly correlated with basal area. Age class was not found to be significantly correlated with any of the three SPOT XS wavebands. TM bands 2, 3, 4,5, and 7 were, however, shown to be significantly correlated with age class. Although significant, the correlation coefficients between the TM or SPOT waveband data and basal area or age class were low (<0.65). Six forest cover types, and an additional water category, were selected as the basis of a land cover classification system for use with the TM and SPOT data. Verification of the classification of the seven cover types using the SPOT XS waveband data resulted in an estimated accuracy of 74.4 per cent. Classification accuracy was slightly reduced (70.8 per cent) when the TM wavebands corresponding to the SPOT XS bands were used as inputs to the classifier. When each of the six visible and reflective infrared TM wavebands were included in the classification process overall accuracy increased to 88.5 per cent. Bockhaus, Khorrams 1992. S. Int J of Remote Sensing 13:3035-3043.
Spatial distribution of biomass in forests of the eastern USA
Sandra L. Brown
US Environmental Protection Agency, National Health and Environmental Effects Laboratory,
Western Ecology Division, 200 SW 35th St, Corvallis, OR 97333, USA
Paul Schroeder
Dynamac Corp., 200 SW 35th St, Corvallis, OR 97333, USA
Jeffrey S. Kern
Dynamac Corp., 200 SW 35th St, Corvallis, OR 97333, USA
Abstract
We produced a map of the biomass density and pools, at the county scale of
resolution, of all forests of the eastern US using new approaches for converting
inventoried wood volume to estimates of above and belowground biomass. Maps
provide a visual representation of the pattern of forest biomass densities and
pools over space that are useful for forest managers and decision makers, and as
databases for verification of vegetation models. We estimated biomass density
and pools at the county level from the USDA Forest Service, Forest Inventory and
Analysis database on growing stock volume by forest type and stand size-class,
and mapped the results in a geographic information system. We converted stand
volume to aboveground biomass with regression equations for biomass expansion
factors (BEF; ratio of aboveground biomass density of all living trees to
merchantable volume) versus stand volume. Belowground biomass was estimated as a
function of aboveground biomass with regression equations. Total biomass density
for hardwood forests ranged from 36 to 344 Mg ha(-1), with an area-weighted mean
of 159 Mg ha(-1). About 50% of all counties had hardwood forests with biomass
densities between 125 and 175 Mg ha(-1). For softwood forests, biomass density
ranged from 2 to 346 Mg ha(-1), with an area-weighted mean of 110 Mg ha(-1).
Biomass densities were generally lower for softwoods than for hardwoods; ca. 40%
of all counties had softwood forests with biomass densities between 75 and 125
Mg ha(-1). Highest amounts of forest biomass were located in the Northern Lake
states, mountain areas of the Mid-Atlantic states, and parts of New England, and
lowest amounts in the Midwest states. The total biomass for all eastern forests
for the late 1980s was estimated at 20.5 Pg, 80% of which was in hardwood
forests.
Brown, Schroeder 1999
Author
Keywords
aboveground biomass, belowground biomass, biomass distribution, carbon cycle,
disturbance, hardwood forests, softwood forests, USA
Key
Words Plus
Model, Storage, Cycle
A
forestry application of Schnute's generalized growth function
Brian V Bredenkamp
Saasveld Forestry Res Ctr, Private Bag X6515,George 6530,South Africa
Timothy
G. Gregoire
Virginia Polytech Inst & State Uinv.,Sch Forestry & Wildlife Resources, Blacksburg,VA 24061
Abstract
A case is presented where the
Chapman-Richards growth function is suitable to describe growth for a certain
period during the life of
a stand of Eucalyptus grandis
in South Africa. Toward the end of that period, diameter growth exhibited
strong asymptotic properties.
After marked competition mortality, the stand resumed growth beyond what had
appeared to be an asymptotic level and the Chapman-Richards function could no
longer be satisfactorily fitted. A
generalized growth function developed by Schnute
successfully tracked this renewed growth. The parametric relationships between the two models are
established. Bredenkamp, Gregoire 1988. For.
Sci. 34(3):790-797.
Additional key words
Chapman-Richards growth
function, Eucalyptus grandis,
C.C.T., stand density effects.
A method of constructing site index curves from measurements of tree age and height --- Its application to inland Douglas-fir
James E. Brickell
Abstract
This
paper describes a method of constructing site index curves from one-time
measurements of age and height of trees in the dominant stand. Site index curves
for Engelmann spruce (Picea - engelmannii Parry) have already been constructed using this
method (1): In
this paper curves are
constructed for inland Douglas-fir (Pseudotsuga menziesii var. glauca (Mirb.) France)
to illustrate how to use the method. This method has the advantage of
being applicable to the kind of site
tree data usually taken in the course of forest inventories. Moreover, the
disadvantages of these data are compensated fzr
to some degree by the fact that the resulting site index curves will
usually be used with the same kind of data, containing the
same hidden effects of past damage. The method is a generalization of
the Osborne-Schumacher method (10), which assumes equal representation of
a particular site quality in all age classes. The
generalization does not require
residuals about the mean curve of height over age to be normally distributed. A disadvantage of the
method proposed i n this paper
is that it
requires a relatively large number of sample trees--at least
1,500 paired measurements of age and height should be available.
Aboveground biomass distribution of US eastern hardwood forests and the use of large trees as an indicator of forest development
Sandra Brown
US
EPA, Natl Hlth & Environm Effects Res Lab,Western Ecol Div, Dynam Corp., 200
SW 35th St, Corvallis,OR 97333
Paul Schroeder
Dynamac Corporation, US Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Western Ecology Division, 200 SW 35th St. Corvallis, OR 97333,USA
Richard Birdsey
Abstract
Past clearing and harvesting of the deciduous hardwood forests of eastern USA
released large amounts of carbon dioxide into the atmosphere, but through
recovery and regrowth these forests are now accumulating atmospheric carbon (C).
This study examined quantities and distribution of aboveground biomass density (AGBD,
M-g ha(-1)) of US eastern hardwood forests and assessed their biological
potential for continued biomass accumulation in the future. Studies have shown
that the presence of a large proportion of the AGBD of moist tropical forests in
large diameter trees (> 70 cm diameter) is indicative of mature and
undisturbed conditions. This relationship was tested as a criterion for the
eastern US deciduous forests to assess their stage of recovery and maturity, and
evaluate their potential for continued C storage. The approach was to compare
AGBD and its distribution in large trees for old-growth forests derived from
published studies and for oak-hickory and maple-beech-birch forests using the
extensive US Forest Service Forest Inventory and Analysis (FIA) data base.
Old-growth forests generally had AGBD of 220-260 Mg ha(-1) with up to 30% in
trees with diameter > 70 cm. In contrast, maximum AGBD for the FIA units was
about 175-185 Mg ha(-1) with 8%-10% in large trees. Most units, however, were
below these maximum values, suggesting that the forests represented by the FIA
inventory are in various stages of recovery from past disturbance. Biologically,
therefore, they have the potential to accumulate significant quantities of
additional biomass, if left unharvested, and thus storing atmospheric C into the
future.
Brown, Schroeder et al. 1997.
Forest
Ecol. Manage.
Author
Keywords
aboveground biomass density, biomass distribution, carbon cycle, disturbance,
hardwood forests, large trees, old-growth, USA
Key Words
Plus
Patterns
Consistent height
growth and growth rate estimates for remeasured plots
David
Bruce
Pacific NW Forest & Range Expt. Stn., Portland,OR 97232,USA
Abstract
Consistent height-growth and growth-rate estimates were made far use in
a managed stand growth simulator
based on data from remeasured Douglas-fir (Pseudotsuga
menziesii) plots in
the Pacific Northwest. Techniques were developed for simultaneous fitting
of height-growth and growth-rate curves, overcoming inconsistent estimates of
age of 4.5-ft-tall trees,
iterative estimating of Site producing polymorphic curves, introducing site
factors and treatment effects, and overcoming minor problems encountered during
the analysis. The equations produced agree well with those developed by King in 1966
for Douglas-fir in the same area, using different data and different
procedures. This suggests the two equations are goad representations of regional
height-growth relations.
Bruce
Additional key words
Douglas-fir, site index, growth
analysis.
Site Index Equations For Radiata Pine In New-Zealand.
Harold E. Burkhart
Virginia Polytech Inst & State Univ, Dept Forestry, Blacksburg, VA 24061 USA
Tennant R.B.
Forest Res Inst, Mensurat Sect, Rotorua,New Zealand
Abstract
Site index
(height of the dominant stand at some specified reference age) is a practical
and commonly used method for quantifying site quality in pure even-aged stands.
Permanent plot records from radiata pine (Pinus radiata D. Don) stands were used
to compute site index equations. The data were divided into groups that might
exhibit different heigh-growth patterns, and separate coefficient estimates were
computed for each group. Coefficients for the 8 groups finally selected are
presented, and limitations in the application of the equations are discussed.
Spatial structure of coastal pelagic schools descriptors in the Mediterranean Sea
Tarub Bahri, Pierre Freon
IRD,
HEA, BP 5045, F-34032 Montpellier Cedex 1, France
Abstract
Biomass estimates during acoustic surveys rely mostly on fish accessibility
which in turn depends on the spatial distribution and structure of schools. In
this paper, we first investigate the spatial behavior of schools through some
of their descriptors in order to assess the interest of a study on the influence
of environmental factors on this behavior. Morphological, energetic and
positioning descriptors of schools were measured in the Catalan and Adriatic
Seas during four acoustic surveys. The spatial structure of the descriptors was
studied using geostatistical methods. The variograms were calculated on the
averaged school descriptors within a sampling distance of 1 nautical mile
(elementary sampling distance unit). Globally, most of the variograms are
structured, depending on the type of descriptor and on the cruise. The results
are discussed according to the topography of the two studied regions, the
temporal variability existing in the data, the dominant species in the area and
the possible biases due to the acoustic device used. Bahri and Freon 2000.
Fish. Res. 48: 157-166.
Author
Keywords
pelagic fish schools, schooling behaviour, spatial structure, variogram,
acoustics
Keywords
Plus
fish schools, anchovy, shape
Effects
of thinning on structural development in 40- to 100-year-old Douglas-fir stands
in western Oregon
John D. Bailey
No Arizona Univ, Sch Forestry, Flagstaff, AZ 86011 USA
John
C. Tappeiner
Oregon State Univ, Dept Forest Sci, Corvallis, OR 97331 USA
Abstract
We studied the composition and structure of the understory in thinned and
unthinned Douglas-fir/western hemlock stands on 32 sites in western Oregon.
These stands had regenerated naturally after timber was harvested between 1880
and 1940; they were thinned between 1969 and 1984. Commercially thinned stands
had 8-60% of their volume removed 10-24 years before the study. Undisturbed
old-growth Douglas-fir stands were present for comparison on 20 of these paired
sites. Conifer regeneration density and frequency were consistently greater in
thinned than unthinned stands. For example, average seedling density in thinned
stands (1433/ha) was significantly (p less than or equal to 0.001) greater than
in unthinned stands (233/ha), but very similar to that in old-growth stands
(1010/ha). Seedling density and frequency were strongly related to the volume
removed and to stand density index (and other measures of overstory density)
just after thinning. In thinned stands, the density of small trees (intermediate
crown class overstory trees and advanced regeneration) was 159/ha, significantly
(p less than or equal to 0.001) greater than in unthinned stands (90/ha), but
not significantly different from that of old-growth (204/ha). The live crown
ratio of these trees in thinned stands (66%) was greater than in unthinned (44%)
and old-growth (48%) stands. Cover and stem density of shrubs was variable in
all three stand types. There was significantly less tall shrub cover in
unthinned stands than in either thinned or old-growth stands, which did not
differ. Thinned stands had the most low shrub cover. Salal and bracken fern
cover was greater in thinned stands than in the other stand types, but there was
no difference in sword fern and Oregongrape cover. Leaf area index in thinned
stands (6.6) was not significantly different from that in unthinned (6.8) and
old-growth stands (7.1); however, there was more leaf area in shrubs in the
thinned stands. Thinning young Douglas-fir stands will hasten the development of
multistory stands by recruitment of conifer regeneration in the understory as
well as by enabling the survival of small overstory trees and growth of advanced
understory regeneration. Thinning will also help develop the shrub layer by
increasing tall shrub stem density and cover of some low shrubs. Bailey and Tappeiner
For.
Ecol. Manage. 108: 99-113.
Author
Keywords
stand structure, old-growth, stand density, understory vegetation
Keywords
Plus
picea-tsuga forests, old-growth forests, gaultheria-shallon, coast range, vine
maple, vegetation, plantations, populations, salmonberry, seedlings
Understory
vegetation in old and young Douglas-fir forests of western Oregon
John D. Bailey
USGS
Biological Resources Division, Forest & Rangeland Ecosystem Science Center,
3200 Jefferson Way, Corvallis, OR 97331, USA
Cheryl
Mayrsohn
USDI
Bureau of Land Management, Eugene District Office, 2890 Chad Drive, Eugene, OR
97440, USA
Paul
S. Doescher
Department
of Rangeland Resources, Oregon State University, Corvallis, OR 97331, USA
Elizabeth
St Pierre
Department
of Rangeland Resources, Oregon State University, Corvallis, OR 97331, USA
John
C. Tappeiner
Department of Forest Science, Oregon State University, Corvallis, OR 97331, USA
Abstract
We studied understory composition in thinned and unthinned Douglas-fir (Pseudotsuga
menziesii (Mirb.) Franco)/western hemlock (Tsuga heterophylla (Raf.) Sarg.)
stands on 28 sites in western Oregon. These stands had regenerated naturally
after timber harvest, 40-70 years before thinning. Commercial thinning had
occurred 10-24 years previously, with 8-60% of the volume removed from below
with the intent to homogenize spacing among trees. Undisturbed old-growth
Douglas-fir stands were present for comparison on 18 of these sites. Total
herbaceous cover was greater in thinned (25% cover) stands than in unthinned
(13% cover) or old-growth (15% cover) stands. Species richness was also greater
in thinned (137) than in unthinned (114) and old-growth (91) stands (P=0.05).
Part of the increased richness was caused by the presence of exotic species in
thinned stands, but there were also more native grass and nitrogen-fixing
species in thinned stands than in unthinned or old-growth stands. Groups of
species differed among stand-types. For example, the frequency of tall cordate-leaved
species was greater in old-growth stands (P = 0.009), but their relative cover
was different only between old-growth and unthinned stands (P = 0.08). Both the
cover and frequency of grasses and sedges in thinned stands were greater than in
unthinned or old-growth stands (P less than or equal to 0.002), Ordination of
shrub cover showed differences among old-growth and unthinned stands compared to
thinned stands, mainly because of the amount of Gaultheria shallon Pursh and
Polystichum munitum (Kaulf.) Presl in heavily thinned stands. Ordination of
herbaceous community data showed that there were much stronger differences among
sites than among stand-types. The lack of difference among stand-types
demonstrates the resiliency of herbaceous communities to disturbance associated
with past and current forest management. Bailey,Mayrsohn
Author
Keywords
thinning, shrubs, herbaceous cover, exotic, old-growth, species richness,
ordination
KeyWords
Plus
salal gaultheria-shallon, species composition, biomass, succession, diversity,
stands, cover, age
Robert
L. Bailey, T.
R. Dell
Southern Forest Experiment Station, USDA Forest service, New Orleans, LA
The
Weibull probability density function is proposed as a diameter distribution
model. Its advantages include flexibility in shape and simplicity of
mathematical derivations. Estimation and interpretation of parameters are
discussed and illustrated with published data. Bailey
and Dell
Exponential distribution, maximum likelihood, percentiles, point individual distance, simulation.
David
E. Adams, Robert L. Bailey
School of Forest Resources, University of Georgia, Athens, GA, USA, 30602
Data from 269 plots were used to fit
height and
site index prediction
equations for
site-prepared
loblolly pine (Pinus
taeda L.)
plantations in
the piedmont and
upper coastal
plain of
Georgia, Alabama and
South Carolina.
Height growth
patterns were
compared with those
of non-pocosin
lower coastal
plain loblolly pine
plantations. No Significant
difference was found
and a
combined model was
fit (490 plots
total). A
splined model is
presented which
constrains
height to be zero
at age
zero.
Adams and Bailey 1989. Can. J. For. Res. 1-36.
James
B. Baker
Forest Science Laboratory, Monticello, AR
W.
M, Broadfoot
Southern Hardwoods Laboratory, Southern Forest Experiment Station, USDA Forest service , in cooperation with the Mississippi Agricultural and Forestry Experiment Station and the Southern Hardwood Forest Research Group, Stoneville, Miss.
Abstract
This paper provides a method of site evaluation for cottonwood, green ash, hackberry, sugarberry, pecan, sweetgum, sycamore, yellow-poplar, and cherrybark, Nuttall, shumard, swamp chestnut, water and willow oaks. The method incorporates an evaluation of the physical, moisture, nutrient, and aeration properties of a soil into a site quality rating. Field tests have demonstrated the accuracy of the technique. The site evaluation technique also provides a basis for possible soil improvement treatments for the 14 hardwood species and estimates of potential productivity for cottonwood, sweetgum, and sycamore plantations. Baker and Broadfoot 1979. USDA For. Serv. Gen. Tech. Rep. SO-26.
Patrick J. Baker
College
of Forest Resources, Box 352100, University of Washington, Seattle, WA 98195,
USA
Jeremy
S. Wilson
USDA
Forest Service, PNW Research Station, College of Forest Resources, Box 352100,
University of Washington, Seattle, WA 98195, USA
Abstract
Canopy stratification is one of the oldest concepts in tropical forest ecology.
However, there has been considerable debate over the existence and
identification of strata. Much of the confusion arises from the differing
definitions of strata (i.e. vertical stratification of phytomass, individual
crowns, or species) and the methods used to evaluate them (e.g. profile
diagrams). In this paper, a quantitative technique for identifying
stratification of individual tree crowns in the forest canopy is presented.
Strata are identified by comparing sorted tree heights to a moving average of
height at the base of the live crown. Height and crown measurements were
obtained from 21 published profile diagrams of forests, representing many
biogeographic regions and covering a wide variety of forest types. The technique
provides an objective measure of canopy strata allowing for a valid comparison
of stratification between the different profile diagrams. Neither the original
author's estimates of strata nor the number of strata detected by the
quantitative technique support the premise that tropical forests have more
strata than temperate forests. With the sole exception of a mono-layered
European Douglas-fir plantation, all forests in this study had two or three
layers. Baker and Wilson 2000. For. Ecol. Manage. 127: 77-86.
Author
Keywords
crown stratification, canopy layers, tree crowns, temperate forests, tropical
forests, profile diagrams, algorithm
Patrick J. Baker
USDA Forest Service, PNW Research Station, 562 King's Highway, Hancock,
NH 03449, USA
Jeremy S. Wilson
College
of Forest Resources, Box 352100, University of Washington, Seattle, WA 98195,
USA
Abstract
Long planning horizons generate substantial uncertainty in forest management,
making management flexibility, the ability to choose between multiple options or
opportunities, a desirable attribute of managed forests. Flexibility in forest
management reflects both the relative rigidity of intervention requirements and
the potential range of development pathways for a stand. The wind stability of
Pacific Northwest Douglas-fir (Pseudotsuga menziesii [Mirb.] France) plantations
is used to demonstrate the concept of management flexibility Dense Douglazs-fir
plantations develop high height to diameter ratios (H/D same units) in the
dominant trees making them unstable and prone to wind damage. The management of
these plantations is inflexible, because without early and timely thinning, the
stands do not contain stable trees that could be expected to survive long
rotations or late thinnings. A combination of reduced planting densities and
site-specific management reduces both the necessity and rigidity of intervention
requirements (e.g., thinning) and expands the number of potential developmental
pathways for these stands. The cost of greater management flexibility is reduced
efficiency of wood volume production: however, greater adaptability to changing
markets, labor conditions, and management objectives may be more important for
many forest owners. While this approach to management is complex, it frees
owners and managers from rigid management requirements and allows for a wider
range of future stand conditions. Baker and Wilson 2001. For. Ecol. Manage. 145:
219-227.
Author
Keywords
management flexibility, Douglas-fir, wind stability, management objectives
KeyWords
Plus
windthrow
V. Clark Baldwin, Jr.
US
Forest Serv, USDA, So Res Stn, 200 Weaver Blvd, Asheville, NC 28802 USA
Harold
E. Burkhart, James A. Westfall
Virginia
Polytech Inst & State Univ, Dept Forestry, Blacksburg, VA 24061 USA
US Forest Serv, USDA, So Res Stn, Pineville, LA 71360 USA
Abstract
PTAEDA2 is a distance-dependent, individual tree model that simulates the growth
and yield of a plantation of loblolly pine (Pinus taeda L,) on an annual
basis. The MAESTRO model utilizes an array of trees in a stand to calculate and
integrate the effects of biological and physical variables on the photosynthesis
and respiration processes of a target tree on an hourly basis. PTAEDA2 sums the
quantities for individual trees to obtain stand results; MAESTRO computes values
for one tree at a time. These models were linked to provide a tool for further
understanding stand, climatic, and edaphic effects on tree and forest
productivity. PTAEDA2 predicts the characteristics of trees grown at a given
stand density, on a given site, for a given length of time. These
characteristics (outputs) are then used as direct inputs into MAESTRO which
assesses the expected impact of environmental changes on tree function, The
results from MAESTRO are fed back into PTAEDA2 to update future predictions by
modifying the site index driver variable of the growth and yield model.
An equation that predicts changes in site index as a function of net
photosynthesis, age, and trees per unit area is the backbone of the dynamic
linkage, The model changes required to link PTAEDA2 to MAESTRO were developed
and reported earlier. This article reviews the earlier work and reports research
results quantifying the relationships between net photosynthesis and the PTAEDA2
growth predictors, thus providing the basis for the MAESTRO to PTAEDA2 feedback
process and integration of these two models. Baldwin, Jr., Burkhart et al. 2001.
For. Sci. 47: 77-82.
Author
Keywords
Pinus taeda, climate change, forests
The
effects of spacing and thinning on stand and tree characteristics of 38-year-old
Loblolly Pine
V. Clark Baldwin, Jr.
US Forest Serv, USDA, So Res Stn, POB 2680, Asheville, NC 28802 USA
US Forest Serv, USDA, So Res Stn, Asheville, NC 28802 USA
US
Forest Serv, USDA, So Res Stn, Pineville, LA 71360 USA
Robert B. Ferguson
US
Forest Serv, USDA, So Res Stn, Athens, GA 30602 USA
Mike R. Strub, David R. Bower
Weyerhaeuser Co, Hot Springs, AR 71802 USA
Abstract
The effects of early and continuous density control on the characteristics of
mature loblolly pine (Pinus taeda L.) were measured at age 38 and analyzed.
Trees in plots planted at spacings of 1.8x1.8, 2.4x2.4, 2.7x2.7, 3.0x3.0, and
3.7x3.7 m were either left unthinned or thinned every 5 years beginning at age
18, to residual basal areas of 27.5, 23.0, 18.4, and 13.8 m(2) ha(-1). Toes
thinned from plot buffer zones at age 38 were selected to represent a final
harvest cross-section of each treatment for evaluation of hole form, component
biomass, and crown architecture. Volume and biomass of cut trees from all
thinnings were included with the age 38 data fur stand level yield comparisons.
Results show thinning effects were generally more pronounced than spacing
effects. Trees of the same diameter at breast height and total height from
heavily thinned stands had more cylindrical lower boles, more upper stem taper,
longer crowns with more and larger branches, more total foliage, and hence more
biomass than trees from unthinned or lightly thinned stands. All levels of
thinning increased the yield of the stand in terms of foliage and branch
biomass, while only light or moderate thinning increased bole biomass and volume
yields. The magnitude of these differences are presented. Baldwin, Jr.
Author
Keywords
Loblolly pine (Pinus taeda L.), spacing, thinning, taper, volume, biomass,
branches, foliage, crown architecture
V.
Clark Baldwin, Jr.
USDA
Forest Service, Southern Research Station, Pineville, LA 71360
Quang
V. Cao
School
of Forestry, Wildlife, and Fisheries, Louisiana State University, Baton Rouge,
LA 70803,
Abstract
The current southern species growth
and yield
prediction capability, new techniques utilized, and modeling trends over the
last 17 years, were examined. Changing forest management objectives that
emphasize more non-timber resources may have contributed to the continuing
general lack of emphasis in modeling the timber productivity of the South’s
largest forest types-mixed pines and mixed pine-hardwood stands. Less than 10
percent of the literature during the period of this review pertained to growth
and yield predictions of that resource. On the other hand, 45 percent of the
literature centered on predicting the productivity of loblolly pine, almost all
in plantations. Clearly the modeling emphasis
V.
C. Baldwin, Jr.
Southern
Forest Experiment Station, USDA-Forest Service, 2500 Shreveport Highway,
Pineville, LA 71360
Louisiana
Department of Agriculture and Forestry, Alexander State Forest, P.0. Box 298,
Woodworth, LA 71485.
A growth and yield prediction system
is presented for use in thinned or unthinned loblolly pine plantations in the
west gulf region. The equations predict cubic- and board-foot volume,
green-weight, and dry-weight yields per unit area of wood only or wood with bark
of entire tree boles, boles to any top diameter limit, and branches. Green and
dry weight of foliage can also be predicted. Total stand yields for weight or
volume are partitioned into l-inch diameter classes to forecast stand and stock
tables for all aboveground tree components for any stage of plantation
development from ages 10 through 45. The data for this system of equations came
from 859 measurements of thinned and unthinned long-term research study plots on
cutover sites located in east Texas, Louisiana, and southern Mississippi. A
computer program COMPUTEP-LOB (Comprehensive Outlook for Managed Pines Using
simulated Treatment Experiments-Planted Loblolly Pine) that produces the yield
tables can be obtained from the authors.
Aboveground
Weight and Volume of Unthinned, Planted Longleaf Pine on West Gulf Forest
Sites
V.
Clark Baldwin
US
Forest Serv., USDA, So Res. Stn., 200 Weaver Blvd, Asheville, NC 28802 USA
Joseph
R. Saucier
USDA,Forest
Serv., Forestry Sci., SE Forest Expt Stn, Carlton St, Athens, GA 30602
Abstract
Volume( cubic foot) and weight predictions (green and dry) are presented in equations and tables for aboveground total tree and tree components of unthinned, planted longleaf pine trees. The 111 sample trees, from 10 stands in Louisiana and Texas, were 10 to 44 years old and ranged from 1 to 21 inches dbh. The data for samplings (dbh<5 inches) were analyzed separately from that of commercial sized trees (dbh>5 inches). The linearized allometric model utilizes the variable D^2H(squared diameter at breast height multiplied by total tree height) the predict volumes and weights of tree component in two size classes. Baldwin, Saucier 1983. Research Paper SO-191. New Orleans, LA: U.S. Dept. of Agriculture, Forest Service, Southern Forest Experiment Station. 25 p. 1983
Validation
of the unthinned loblolly pine plantation yield model USLY-COWG
V.
C. Baldwin, Jr.
Southern
Forest Experiment Station, USDA-Forest Service, 2500 Shreveport Highway,
Pineville, LA 71360
Louisiana
Department of Agriculture and Forestry, Alexander State Forest, P.0. Box 298,
Woodworth, LA 71485.
Abstract
Stand
structure predictions from an unthinned loblolly pine plantation yield
prediction system (USLYCOWG computer program) were compared with observations
from 80 unthinned loblolly pine plots. Overall, the predicted estimates were
reasonable when compared to observed values, but predictions based on input data
at or near the system's limits may be in error by as much as 14 percent.
Correlations between observed and predicted values for the variables selected
ranged from 0.72 to 0.96.
Key
words
taeda, validation, volume prediction, unthinned plantation yields
Louis
A. Ballard,
James N. Long
Department
of Forest Resources, Utah State
University, Logan,
UT 84322-5215. U.S.A.
We
examined the relationship between stand density and stem quality characteristics
for lodgepole pine (Pinus
contorta). The
influence of initial stand density on
end of
rotation log
quality was inferred by analyzing data from unmanaged, rotation-age stands.
Quality characteristics examined included first log branch diameters, taper, wood density, and the proportion of
sapwood. After
differences in diameter at breast height were accounted for, only branch size
was strongly influenced by stand density. A strong negative exponential
relationship was found between the mean of the five largest branches per first
log and number of
trees per
hectare.
Use
of pretreatment increment data in evaluating tree growth response to
fertilization
T.
M. Ballard,
N. Majid
Department
of Soil
Science and Faculty of
Forestry,
University of Brithish Columbia. Vancouver. B.C. Canada
V6T IW5
The
use of pretreatment
increment can lead to improved estimates of individual
and average tree growth response to fertilization, by helping to adjust for site
as well
as stand
structure differences between fertilized and control areas. It has applications in research using either single-tree or plot
fertilization, and also in
estimating responses to operational fertilization. Particularly useful equations
are R =Af
–(Bf)av(Au/Bu)
and t =
av(Af/Bf)-av(Au/Bu)
where R
is an
estimate of the
absolute magnitude of individual tree growth response to fertilization: A
and B are
increment after and before fertilization. And f and u denote fertilized
and unfertilized trees respectively; av signifies the average of several replicates; and t is
an index of
whether response
has occurred. Equations were evaluated by examining branch length increment data
from foliar spray application of iron and copper to Pinus
contorta Dougl.
(lodgepole pine) and of nitrogen and iron to Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir).
R.
James Barbour, Dean L. Parry
Forestry
Sciences Laboratory, P.O. Box 3890, Portland, OR 97208.
This report examines the differences in wood characteristics found in coastal Pacific Northwest Douglas-fir (Pseudotsuga mensziesii (Mirb.) Franco) trees harvested at the age of 70 to 100 years old to wood characteristics of trees harvested at the age of 40 to 60 years. Comparisons of differences in domestic log grades suggest that the proportion of log volume in the higher grades (Special Mill and No. 2 Sawmill) increased with both stand age and tree size. Simulation of lumber grade yields based on log characteristics suggests that yields of higher grades of lumber increased until about age 60 to 70, and then leveled off over the rest of the age range examined in this analysis. We included structural lumber products in the analysis but not higher value appearance grade products, and some evidence suggests that yields of these products might have begun to increase in the oldest trees. The analysis also showed that the younger trees had larger branches and more juvenile wood, possibly because they had been grown in stands that received a higher level of early stand management than the older trees. If these young trees were grown to the ages of 70 to 100, they likely would not produce the same log and lumber grade yields found in the older trees we examined. Barbour and Parry 2001. USDA For. Serv. Res. Pap. PNW-GTR-510.
Keywords
Wood quality, log grade, lumber grade, thinning,
Douglas-fir, Pseudotsuga mensziesii, ecosystem management, sustainable
forestry.
R. James Barbour
Us Forest Serv, Pacific NW Res Stn, USDA, P.O.Box 3890,Portland,OR 97208
Stuart
Johnston
Us Forest Serv, Siuslaw Natl Forest USDA, P.O. Box 67,Mapleton, Or 97453
John
P. Hayes
Oregon
State Univ, Dept Forest Sci, Coastal Oregon Product Enhancement Program,
Corvallis, Or 97331
Gabriel F. Tucker
Oregon State Univ, Dept Forest Sci, Cascade Ctr Ecosyst Management Corvallis,OR 97331
Abstract
Hundreds of thousands of hectares of Douglas-fir (Pseudotsuga menziesii [Mirb.]
Franco) plantations in coastal forests in the U.S. Pacific Northwest were
established over the past 40 years. Density management regimes designed to
increase structural and compositional diversity in these plantations are being
tested and implemented on an operational scale, These regimes are designed to
promote various tree and stand characteristics, such as trees with large limbs,
stands with multi-layered canopies, and dense unthinned patches, Changes in
management policy associated with these types of regimes raise questions about
the potential to manage for both ecosystem values and timber production. We used
state-of-the-art models to simulate stand growth and wood product yields under
several silvicultural prescriptions. The results indicated that timing and
intensity of early thinnings are critical in determining both stand structure
and wood quality. We concluded that it should be possible to manage Douglas-fir
plantations to provide a high degree of structural diversity and wood products
with quality similar to that grown in many industrial plantations. Barbour,
Johnston et al. 1997. For. Ecol. Manage. 91: 205-219.
Author
Keywords
ecosystem management, wildlife, habitat, silviculture, wood properties, wood
products, timber production
KeyWords
Plus
western Oregon, forests, snags, birds
Barclay HJ, Trofymow JA, Leach RI
Pacific
Forestry Centre, 506 West Burnside Road, Victoria, BC, Canada, V8Z 1M5
Abstract
Measurements of leaf area index (LAI) taken with photometers such as the LAI2000
are biased by boles and branches which stop part of the light from reaching the
photometer. We estimated how much of the sky would be obscured by boles in an
immature stand of Douglas-fir (Pseudotsuga menziesii (Mirb) France) that was
stem-mapped and of known diameter, height and height-to-live-crown. These
yielded gap fractions which were then converted to bole area index (BAI) via the
algorithm used by the LAI2000. The mean BAI, as a fraction of the effective leaf
area index (LAIe) calculated by the LAI2000, ranged from <0.01 for
Douglas-fir at 24 years of age to about 0.1 at 48 years. Comparing readings on
Douglas-fir trees defoliated by root rot with readings on fully foliated trees
yielded a proportion of 0.41, which included branches. Measurements were also
taken on clumps of maple (Acer macrophyllum Pursh) and alder (Alnus rubra Bong.)
both before and after leaf-fall, yielding corresponding proportions, including
branches, of 0.41 and 0.25, respectively. The values obtained this way are
probably upper limits. The contributions of boles may be appreciable,
particularly in mature unthinnned stands with closed canopies. Barclay, Trofymow
et al. 2000. Agri. For. Meteorology. 100: 255-260.
Author
Keywords
leaf area index, LAI-2000, Douglas-fir
KeyWords
Plus
stands
College
o f Forest
Resources and Center for Quantitative Science in Forestry, Fisheries, and
Wildlife,
University
of Washington, Seattle, WA 98195, U.S.A.
Guillermo
A. Mendoza
Department
of Forestry, University of Illinois, Urbana, IL 61801, U.S.A.
Abstract
Forest land management planning provides a rich
environment for the use of optimization techniques that incorporate multiple
criteria and operate within a soft optimization decision environment. Using de
novo programming, several approaches for examining planning problems are
described where the objective is not simply to optimize a given system,
but to design an optimal system. Both single and multiple objective
linear programming models are used to illustrate this new approach and several
illustrative examples are discussed.
Using a direct search algorithm to optimize species composition in uneven-aged forest stands
B.
Bruce Bare, Daniel Opalach
College of Forest Resources and Center for Quantitative Science in Forestry, Fisheries and Wildlife, University of Washington, Seattle, WA 98195, USA
Abstract
Describes an approach for determining the optimal sustainable equilibrium diameter distribution and species composition for uneven-aged forest stands. A direct search, derivative free, constrained nonlinear programming algorithm is applied to a deterministic version of the Stand Prognosis Model. The diameter distribution for each species is described by a two-parameter Weibull distribution and number of trees per acre. The optimization problem is formulated in terms of these three decision variables per species. Results are presented for both board and cubic foot growth objective functions, and the species composition is allowed to consist of one to three species. Few of the optimal solutions produce balanced diameter distributions, although all are sustainable over the cutting cycle. Solutions involving a mixture of the three permissible species produce more volume growth than do either the one or two species alternatives. Bare and Opalach 1987. IUFRO For. Growth Modelling and Prediction Conference, Minneapolis MN, August 24-25 1987.
College of Forest Resources and Center for Quantitative Science in Forestry, Fisheries and Wildlife, University of Washington, Seattle, WA 98195, USA
Systems analysis is very effective in determining the the overall effect of biological and financial decisions on a total forest management system. The pedagogic use of a competitive simulation model enable students to forest management to visualize the operational problems of the forest manager from the total systems point of view. Students were receptive to and enjoyed the game. Believed that the game provided them with experience in making decision within a management-oriented environment, and felt that the game environment provided an opportunity to visualize interrelations between the biological and financial components of a forest management system. Bare 1970. J. For. 68: 554-557.
Growth of Ponderosa Pine poles thinned to different stocking levels in Central Oregon
James
W. Barrett
USDA Forest Service, Pacific Northwest Forest and Range Experiment Station, Portland, OR
Abstract
This paper resents 15-year results of one installation of a west-wide
study of growing-stock levels in even-aged ponderosa pine. Growth was related to
growing-stock level in a 65-year-old pole stand on an above average site,
Periodic growth is presented for 10 years after the initial thinning and for 5
years after a second thinning to six assigned growing-stock levels. Annual
growth in diameter during the 5 years after initial thinning ranged from an
average of about 0.28 inch at the lowest growing-stock level to 0.10 at the
highest. These rates increased slightly during the following decade, but
differences between growing-stock levels remained about the same. These growth
relations resulted in much larger trees at the lower growing-stock levels
15years after the initial thinning. Barrett 1983. USDA For. Serv. Res. Pap. PNW-311.
Keywords
Growing stock, increment/yield, thinning effects, even-aged stands,
improvement cutting, stand density, ponderosa pine, pinus ponderosa
James
W. Barrett
USDA Forest Service, Pacific Northwest Forest and Range Experiment Station, Portland, OR
Abstract
This paper presents height growth and site index curves and equations for even-aged, managed stands of ponderosa pine east of the Cascade Range in Oregon and Washington where height growth has not been suppressed by high density or related factors. Barrett 1978. USDA For. Serv. Res. Pap. PNW-232. 14p.
Keywords
Increment (height), site index)
stand height/age, measurement systems, stem analysis, ponderosa pine, Pinus
ponderosa, Oregon
(Eastern), Washington (Eastern).
A
growth model for mixed forest stands
Bartelink HH
Univ.
Wageningen & Res. Ctr., Sect Forestry, Dept. Environm. Sci., POB 342, NL-6700 AA
Wageningen, Netherlands
Abstract
The area of mixed forest stands in western Europe has significantly increased
during recent decades and is still increasing today. Tools are needed to support
the forest management decision taking in these mixed forests. However, though
pure stands have been modelled extensively and rather successfully for decades,
relatively few models for mixed-species stands have been developed. In this
study, a mechanistic tree-based model of mixed forest growth is presented and
applied. The aims of the study were (1) to present the modelling concept, (2) to
compare growth and yield of mixed stands and monospecies stands, and (3) to
demonstrate potential model application by simulating effects of management on
mixed Douglas-fir/beech stands. The effects of stand composition and management
on mixed stand productivity were investigated by simulating a replacement
series. Simulation results showed that in general the yield of the mixture was
somewhere in between the yield levels of the two monocultures. In stands with a
low proportion of basal area of Douglas-fir, the productivity of Douglas-fir was
lower than could be expected from its basal area share in the mixture; in stands
with more than 40% of Douglas-fir, the opposite was the case. The productivity
of beech in stands with few Douglas-fir was generally higher than expected from
its proportion of basal area in the mixture, but much lower in mixtures with a
higher Douglas-fir proportion. Thinning had a strong impact on productivity of
the mixed stands. Yield of the mixtures was not linearly related to the basal
area fraction of Douglas-fir present at the start of the simulations; simply
combining monospecific yield tables will thus result in biased estimates of the
yield of a mixed stand. Bartelink 2000. For. Ecol. Manage. 134: 29-43.
Author
Keywords
beech, competition, Douglas-fir, radiation, simulation, thinning
KeyWords
Plus
douglas-fir stands, allometric relationships, root density, needle area,
radiation, biomass, trees, beech
Bartelink HH
Agr
Univ Wageningen, Dept Environm Sci, Sect Forestry, POB 342, NL-6700 AH
Wageningen, Netherlands
Abstract
As part of a study on growth of mixed-species forest stands, a spatial model has
been developed that simulates the absorption of photosynthetically active
radiation (PAR) by individual trees and the transmission through the forest
canopy. Model performance was
tested by comparing simulated transmissions with field measurements. The model
was applied to analyze the role of crown characteristics on radiation
transmission and on absorption (APAR) by individual trees, and to analyze the
effects of stand density and foliage clustering on transmission. Simulated
transmission patterns appeared largely comparable with field measurements.
Discrepancies between field measurements and model estimates could be attributed
to interception by stems and (dead) branches: which were not part of the model.
Analysis of absorption by trees showed that APAR was closely related to tree
leaf area in closed canopy stands, but that in the open stand the relationship
was less clear. This indicates that in open stands spatial information on tree
position and crown dimensions will strongly affect absorption by individual
trees. Uncertainties in leaf area estimates, due to variability in allometric
relationships, had only small effects on APAR of the trees. Analysis of the role
of stand density on the extinction-coefficient (K) showed that model estimates
of K were clearly lower than values calculated with the Lambert-Beer theory:
simulated K increased with increasing LAI, varying between 0.17 and 0.33 in case
of Douglas fir and 0.30-0.63 for Beech. The degree of clustering decreased with
LAI, amounting to a multiplier of 2.2-4.2 and 1.1-2.4 for Douglas fir and Beech,
respectively. The model was considered a suitable tool in simulating growth and
development of heterogeneous forests like mixed-species stands, because it
enables to account for the growing conditions of individual trees in the forest
canopy. Bartelik 1998. Ecol. Model. 105: 213-225.
Author
Keywords
light, spatial model, extinction-coefficient, Douglas fir, Beech
Keywords
Plus
leaf-area index, global radiation, light, model, canopies, array
Allometric
relationships on biomass and needle area of Douglas-fir
Bartelink HH
Agr
Univ Wageningen, Dept Environm Sci, Sect Forestry, POB 342, NL-6700 AH
Wageningen, Netherlands
Abstract
The aims of the study were: (1) to establish allometric relationships among stem
and crown dimensions, biomass, and needle area; (2) to describe the above-ground
dry matter distribution; (3) to determine the relationship between sapwood area
and needle area; and (4) to describe the vertical distribution of tree needle
area and branch biomass. Twenty-three trees out of four stands were sampled.
Strong stand-independent correlations were found between stem and crown
dimensions. Stem diameter at breast height (dbh) was non-linearly related to
tree height, and linearly related to crown radius. Tree biomass generally
increased with increasing dbh. The relationship between stem biomass and dbh was
stand-independent, but the relationship between crown biomass and dbh clearly
differed between the stands. Best results were obtained after two-sided
logarithmic transformations. The ratio between needle biomass and branch biomass
significantly decreased with increasing tree size. Dry matter distribution
differed between trees from different crown classes. suppressed trees had
relatively less crown biomass.
Specific needle area decreased with needle ageing and increased from tree top to crown base. SLA strongly varied within trees, but not between trees: needle biomass was strongly linearly related to needle area. Needle area was linearly correlated with sapwood cross-sectional area at breast height: ratio differences could be ascribed to differences in crown base height.
Vertical locations of the maximum needle area density (m(2) m(-)3) and branch biomass density (kg m(-3)) differed, reflecting the increase of the needle biomass/branch biomass ratio when moving upward in the crown. Location of the maximum density depended on canopy closure, but was generally below the middle of the crown. Bartelink 1996. For. Ecol. Manage. 86: 193-203.
Author
Keywords
Douglas-fir, allometry, sapwood, dry matter distribution, needle area,
pipe-model
KeyWords
Plus
leaf-area, sapwood area, equations, stands, index, pine
Kenneth
E. Bottoms , E. T. Bartlett
Department of Range Science, Colorado state University, Fort Collins 80523
Abstract
One of the major weaknesses of using linear programming in natural resource management is that only a single criterion for determining the optimal strategy is allowed. A goal programming model is presented that allows for multiple, conflicting goals. Results are provided for a management area in northern Colorado. The trade offs between goals are demonstrated by comparison of results from multiple runs in which the order of goal references is varied. Goal programming is shown to be a very flexible decision aiding tool which can handle any decision problem formulated by linear programming more efficiently. Bottoms and Bartlett 1975. J. Range. Manage. 28: 442-447.
Spatial variability of topsoil characteristics within one silty soil type- Effects on clay migration
Bartoli F, Burtin G
Univ
Nancy 1,Cnrs,Upr 6831,Ctr Pedol Biol, Bp 5,F-54501 Vandoeuvre Nancy,France
Royer
JJ
Cnrs,Ctr
Rech Petrog & Geochim,F-54501 Vandoeuvre Nancy, France
Gury
M, Gomendy V, Philippy R
Univ
Nancy 1,Cnrs,Upr 6831,Ctr Pedol Biol, Bp 5,F-54501 Vandoeuvre Nancy,France
Leviandier T, Gafrej R
Cemagref,Div Hydrol,F-92164 Antony, France
Abstract
In order to understand and to model soil runoff erosion as well as to optimize
sampling schemes, improved understanding of spatial variability of clay and some
other soil erosion parameters is needed. For this purpose, two complementary
approaches to the study of spatial variability of silty topsoil characteristics,
the pedological approach and the fractal approach applied to geostatistics, were
carried out in the context of soil erosion within the intensive cereal
agriculture zone of northwestern Europe. Fractal geometry provides one synthetic
key to the description of classical geostatistical tools such as variograms.
Spatial structures of soil properties of each of the three topsoil pedological
units were mostly characterized along the slope by the ranges of the fractal
one-dimensional space domains and their scale invariants: the fractal
dimensions. Results suggest that, within each topsoil pedological unit, these
scale invariants are relevant qualifiers of the intrinsic topsoil variability,
which can be modelled as a fractal Brownian process and should be incorporated
in simple recursive or complex network soil erosion models. Different surface
fractal dimensions, in a one-dimensional space, have been found within these
three topsoil units for each soil parameter studied (multifractals), All the
data have been aggregated within the whole one-dimensional slope transect in
order to obtain both possible general scale laws on clays and other soil
characteristics and possible evidence concerning underlying soil erosion
mechanisms by particle runoff. Bartoli, Burtin
1995. Geoderma. 68: 279-300.
KeyWords
Plus
fractal dimensions, aggregate stability, multiscale sources, water properties,
erosion, runoff, fragmentation, infiltration, porosity, networks
Deborah
Barton, Shimna M. Gammack, Michael F. Billett, Malcolm S. Cresser
Department of Plant and Soil Science, University
of Aberdeen, Old Aberdeen AB24 3UU Scotland, UK
Abstract
Three sites in north-east Scotland were selected to compare soil characteristics
of acidification-sensitive sites under Calluna vulgaris heathland and
afforestation. At each site, fences separate Calluna heathland from Scots pine
plantation on podzol profiles evolved from granitic parent material on gentle
slopes in the altitude range 200-500 m. In total, 30 soil pits were dug, with
five for each land use-type at each of the three sites. Samples of each horizon
were analysed for pH, sulphate adsorption/ desorption characteristics, cation
exchange properties, carbon and nitrogen contents, bulk density and texture. As
expected, acidification to depth had occurred in the forest sites. However,
although the forest soils at depth showed less capacity for sulphate adsorption,
as might be expected from increased atmospheric aerosol and pollutant trapping
and greater water interception loss under trees, they did not contain more
PO43--extractable sulphate. This may reflect the combined effects of soil pH
differences and changes in concentrations and composition of soluble organic
matter upon sulphate adsorption, although interpretation is also complicated by
textural differences between forest and heathland soils. (C) 1999 Published by
Elsevier Science B.V. All rights reserved. Barton,
Gammack et al. 1999. For. Ecol. Manage. 114: 151-164.
Keywords
Plus:
dissolved organic-carbon, wind river mountains, sulfate adsorption, sulfur
constituents, acid-rain, deposition, retention, iron, ph, sorption
Forest landscape management modeling using simulated annealing
Emin Z. Baskent
Karadeniz Tech Univ, Orman Fak Ogretim Uyesi, TR-61080 Trabzon, Turkey
Univ New Brunswick, Fac Forestry & Environm Management, Fredericton, NB E3B 6C2, Canada
Abstract
This paper presents a new landscape management model using a simulated annealing
approach. The model is capable of achieving target landscape structure, in the
form of composition and configuration objectives, in a near optimal fashion by
spatially and temporally scheduling treatment interventions. Management
objectives and constraints are identified in an objective function. Penalty cost
functions for each objective establish common non-monetary units, and a
mechanism for making trade-offs among different objectives. Management
strategies, as well as alternative solutions as combinations of treatment
scheduling of each stand, are formulated around treatment regimes, including
varying intensities of planting, precommercial thinning, commercial thinning,
two-stage harvesting and clear-cutting.
The model then examines alternative solutions using a heuristic process, and evaluates their effects on the objective over an entire planning horizon. The model was tested on a 20,000 ha (987 stands) hypothetical forest landscape with four replicates, differing in initial age class composition and spatial configuration. Management objectives included: (i) maximizing harvest volume, (ii) minimizing deviations in harvest flow, (iii) maintaining harvest block size between 40 and 100 ha, (iv) maintaining a one period adjacency delay, and (v) achieving an inverse-J distribution of harvest opening patches. Objective accomplishment, when compared to an aspatial optimal solution, varied from 72% for even flow harvest, to 99.9% for adjacency delay. These results generally reflect the objective priorities established for the test.
Results also suggested that the achievement of an inverse-J distribution of harvest opening patches depended not only upon the spatial harvest pattern, but initial forest conditions as well. In the case of the test forests, however, the effects of different initial age class structure and spatial configuration lasted a relatively short time. We conclude that simulated annealing allows a great deal of flexibility in designing landscape management in a near optimal fashion. Baskent and Jordan 2002. For. Ecol. Manage. 165: 29-45.
Author
Keywords
landscape management, modeling, simulated annealing, harvest scheduling
KeyWords
Plus
harvest scheduling problems, search procedure, optimization
Emin Z. Baskent
Karadeniz Tech Univ, Orman Fak Ogretim Uyesi, TR-61080 Trabzon, Turkey
Univ New Brunswick, Fac Forestry & Environm Management, Fredericton, NB E3B 6C2, Canada
Nurullah
AMM
Faculty of Forestry and Environmental Management, University of New Brunswick, PO box 44555, Fredericton, NB E3B 6C2, Canada
Abstract
Contemporary forest management design is generating innovative ideas as it
evolves towards the management of forest landscapes. These ideas embody
different management paradigms, modelling approaches and software engineering
techniques. We explore these three in detail and suggest an ecological landscape
management (ELM) paradigm coupled with meta-heuristics modelling and
object-oriented software engineering techniques as a suitable framework for
designing management for forest landscapes. We hope the paper provides insight
and stimulates discussion about various forest landscape management design
approaches. Baskent, Jordan et al. 2000. For. Chron. 76: 739-742.
Author
Keywords
forest landscape management, forest modelling, software engineering
KeyWords
Plus
disturbance, future
Spatial Wood Supply Simulation Modeling
Emin Z. Baskent
Karadeniz Tech Univ, Orman Fak Ogretim Uyesi, TR-61080 Trabzon, Turkey
Univ New Brunswick, Fac Forestry & Environm Management, Fredericton, NB E3B 6C2, Canada
Abstract
Conventional wood supply simulation models have been found inadequate in both
calculating true assessments of wood supply and in translating management
strategies into on-the-ground management design. These models treat forests as
aspatial entities and are unable to include economic and wildlife considerations
in management design and calculation of wood supply. This paper presents and
discusses the design and construction of a GIS-based (geographic information
system) spatial wood supply model. The model uses geographic distribution of
stand development types and stages and their change over time to control
harvesting and calculate wood supply based on extraction economics ($/m3) and
wildlife habitat values (opening size and green-up). The paper points out that:
a spatial model is capable of producing harvest schedules and forest performance
indicators that reflect geographic context as well as condition of stands; a GIS
database is more important in spatial modelling than GIS technology; harvest
blocks are the basic geographic element in spatial modelling; a spatial model
provides a truer assessment of wood supply; and stand topology makes it
relatively easy to integrate wildlife and timber management.
Baskent and Jordan 1991. For. Chron. 67: 610-621.
Author
Keywords
timber, wildlife, forest management, GIS, simulation model, wood supply
A
case-study in spatial wood supply analysis
Emin Z. Baskent
Karadeniz Tech Univ, Orman Fak Ogretim Uyesi, TR-61080 Trabzon, Turkey
Univ New Brunswick, Fac Forestry & Environm Management, Fredericton, NB E3B 6C2, Canada
FORESTRY
CHRONICLE
68 (4): 503-516 AUG 1992
Abstract
This paper shows the effects of extraction economics and wildlife habitat values
on wood supply for a 9,640 stand forest in New Brunswick. Using a spatial wood
supply model developed at the University of New Brunswick, the paper quantifies
and explains wood supply effects of harvest blocking, road cost and harvest
adjacency delay. Eight spatial strategies test harvest scheduling based on
geographic forest structure (distribution of stand developmental types and
stages). Given a forest of mostly regenerating and mature developmental stages,
wood supply reductions vary from 4.9 % to 19.2 % when compared to a convention
aspatial assessment. The paper presents and explains reductions for all eight
spatial strategies; but concludes that all are explained by the impacts that
harvest blocking, road cost, or harvest adjacency delay have, singly, or in
combination, on either mortality losses or the rate at which harvesting recycles
forest area. Baskent and Jordan 1992. For. Chron. 68: 503-516.
Author
Keywords
forest management, forest dynamics, gis, wildlife, simulation, wood supply,
harvest scheduling
A
dynamic model of growth in defoliated fir stands
G.
Baskerville, S. Kleinschmidt
Faculty of Forestry, University of New Brunswick, Fredericton, N.B., Canada E3B 5A3 Canada
Abstract
Constructing a dynamic model of growth in fir stands (age 30-70 years). based on gross physiological structure of the stand made possible reasonable qualitative and quantitative forecasts of growth loss due to defoliation by insects in a wide variety of situations. Analysis of the model, in comparison with the natural world, indicates that the key to understanding growth loss in fir stands subjected to defoliation by spruce budworm lies in more explicit knowledge of the mechanisms of new foliage production. Baskerville and Kleinschidt 1981. Can. J. For. Res. 11: 206-214.
Use
of logarithmic regression in the estimation of plant biomass
G.L.
Baskerville
Canadian Forestry Service, P.O. Box 4000, Fredericton, New Brunswick.
Abstract
The Basic assumption of regression analysis are recalled with special reference to the use of a logarithmic transformation. The limitations imposed on inference-making by failure to comply with these assumptions are discussed and ways to avoid the limitations indicated. A systematic bias of the order of 10 to 20% which is inherent in most, if not all, prior uses of the logarithmic equation to estimate plant biomass is noted as is the correction for the bias. Baskerville 1972. Can. J. For. Res. 2: 49-53.
Relative
stocking index - a proposed index of site quality
Berguson WE
Univ Minnesota, Dept Soil Sci,St Paul,Mn 55108
Grigal
DF, Bates PC
Univ
Minnesota, Dept Soil Sci,St Paul,Mn 55108
Abstract
Site index is difficult to implement and interpret in multispecies,
multiple-aged stands, and its relationship to site factors is obscure. Using
data from the USDA forest inventory and analysis (FIA) for the Lake States, we
developed log-log relationships between mean tree size and stand density for
five cover types. Fits were good, with r2 from 0.96 to 0.98 and slopes from
-0.948 to -0.995. We define an alternative index of site quality, the relative
stocking index (RSI), as the ratio of a stand's measured density to that
predicted using the log-log relationship for its cover type (the norm). We
divided the range of RSI into three classes for each type (<0.9 of norm,
>0.91 but <1.1 of norm, and >1.1 of norm). Based on analyses of the
1977 and 1990 FIA data from Minnesota, class assignments for individual stands
remained constant over that 13-year period. Relationships between site factors
and either RSI classes or analogous classes based on site index were examined in
a subset of 169 stands. Temperature, precipitation, silt content of surface
soil, and calculated annual water deficit all differed significantly among RSI
classes, but not among site-index classes. The RSI is easy to apply, robust
(resistant to change), and related to site factors. It merits additional
examination as an index of site quality, especially in heterogenous stands.
Berguson, Grigal 1994. Can.
J. For. Res. 24: 1330-1336.
KeyWords
Plus
white spruce plantations, mixed-species stands, nitrogen mineralization,
alternative approach, productivity, soil, density, states, biomass, carbon
Modeling the spatial structure of topical forests
Joao L.F. Batista
Univ Sao Paulo, Luiz de Queiroz Coll Agr, Dept Forest Sci, CxP 9, BR-13400970 Piracicaba, SP, Brazil
Abstract
The spatial structure of tropical forest stands under different management
conditions was modeled as a series of different spatial point processes. Spatial
patterns were first assessed by K-function analyses to help choose a point
process appropriate for observed patterns. The homogenous Neyman-Scott process
accurately described live tree distribution in clear cut areas, when tree
patterns tended to be aggregated. Parameters were estimated by minimizing
Diggle's modified least squares criterion, and goodness-of-fit was assessed by
comparison to confidence envelopes constructed by Monte Carlo simulation.
Parameter estimates can be interpreted to help understand the ecological
processes influencing re-colonization of disturbed areas. The inhomogeneous
Poisson process was investigated for simulating the spatial pattern of ingrowth
trees in lower canopy strata. The intensity function of this process was
inversely proportional to variables representing canopy density. As assessed by
Monte Carlo generation of confidence envelopes, the inhomogeneous Poisson
process successfully portrayed the influence of canopy structure on understory
plant distribution in most stands. Tree mortality was modeled as a thinning
process in which the probability of individual tree mortality was conditional on
subject tree attributes and competitive environment. The thinning function took
the form of a generalized linear model with a binomial error distribution and
legit link function. In most stands, tree neighborhood variables were powerful
predictors of mortality, but they were not important predictors in all plots.
This suggests that the surrounding forest structure of a subject tree has
considerable influence on its morality, but competition is not the sole cause of
tree morality in tropical forests. Batista and Maguire 1998. For. Ecol. Manage. 110: 293-314.
Author
Keywords
forest management, spatial pattern modeling, K-function, point process model,
Neyman-Scott process, inhomogeneous Poisson process
KeyWords
Plus
tropical forests, tree dispersion, pattern, recruitment, vegetation, diversity,
dynamics, ecology, pine
Hybrid
growth model to predict height and volume growth in young Eucalyptus globulus
plantations
Battaglia M, Sands PJ
Cooperat
Res Ctr Sustainable Prod Forestry, GPO Box 252-12, Hobart, Tas 7001, Australia
Candy SG
Forestry
Tasmania, GPO Box 207B, Hobart 7001, Australia
Abstract
A process-base site productivity model (PROMOD) was hybridized with an empirical
growth projection model (NITGRO) developed for Eucalyptus nitens plantations.
The subsequent hybrid growth model was used to predict the time course of height
and volume growth in 16 plantations of E. globulus located in northern Tasmania,
Australia. Growth in these plantations war constrained by temperature, water
stress, waterlogging and poor site nutrition. With the help of a few simple,
easily obtained site descriptors, PROMOD was used to predict the site index for
these sites. This site index was used to run NITGRO, Comparison of predictions
with observed height and volume growth indicated that height growth was
predicted accurately, but that estimates of volume growth were biased. The bias
in the estimates of volume growth may be the result of the application of a
growth model developed for E. nitens plantations to E. globulus plantations.
Battaglia, Sands et al. 1999. For. Ecol. Manage. 120: 193-201.
KeyWords
Plus
carbon balance model, pinus-radiata, site index, Douglas-fir, nitrogen, yield,
productivity, variables, moisture, curves
Spatial
structure of light and dipterocarp seedling growth in a tropical secondary
forest
Dan Bebber, Nick
Brown
Univ
Oxford, Dept Plant Sci, S Parks Rd, Oxford OX1 3RB, England
Martin Speight
Univ
Oxford, Dept Zool, Oxford OX1 3PS, England
Pedro Moura-Costa, Yap Sau Wai
INFAPRO, Lahad Datu 91112, Sabah, Malaysia
Abstract
Variation in forest canopy openness influences the growth and survival of
seedlings below, and is therefore of practical importance when wishing to
restock a forest with valuable timber species after logging. In this study,
growth and light environment of dipterocarp seedlings in an enrichment planting
project in secondary lowland forest in Borneo were analysed using geostatistics,
in order to determine the spatial relationships between canopy openness and
seedling performance, Seedling growth was correlated with canopy openness
measures up to 50 m away along planting lines but was uncorrelated across
planting lines, because the dense understorey between planting lines blocked
lateral light. It is recommended that planting be conducted in patches rather
than along lines, so that understorey clearance can allow light from canopy gaps
in all directions to reach seedlings. Bebber, Brown et al. 2002. For. Ecol. Manage. 157: 65-75.
Author
Keywords
geostatistics, enrichment planting, dipterocarpaceae, seedling growth, spatial
autocorrelation, canopy openness
Keywords
Plus
lowland rain-forest, solar-radiation, canopies, gap, autocorrelation, understory,
sabah, danum
Field Methods and Data Processing Techniques Associated With Mapped Inventory Plots
William A. Bechtold, Stanley J. Zarnoch
USDA Forest Service, Southern
Research Station, 200 Weaver Blvd., Asheville, NC, 28802.
Abstract
The U.S. Forest Inventory and Analysis (FIA) and Forest Health Monitoring (FHM) programs utilize a fixed-area mapped-plot design as the national standard for extensive forest inventories. The mapped-plot design is explained, as well as the rationale for its selection as the national standard. Ratio-of-means estimators am presented as a method to process data from mapped inventory plots. Bechtold and Zarnoch et al. 1999. USDA For. Serv. Proceedings. RMRS-P-12. 421-424.
Comparisons
of modeled height predictions to ocular height estimates
W.A.
Bechtold, S.J. Zarnoch, W.G. Burkman
USDA Forest Service, Southern Research Station, Asheville, NC.
Abstract
Equations used by USDA Forest Service Forest Inventory and Analysis
projects to predict individual tree heights on the basis of species and dbh were
improved by the addition of mean overstory height. However, ocular estimates of
total height by field crews
were more accurate than the statistically improved models, especially
for hardwood
species. Height predictions from the improved equations attained the desired
measurement quality objective only 57% of the time, while ocular estimates
achieved the desired accuracy 75% of the time. South. J. Appl. For.
22(4):216-221.
Structure
of pine stands in the Southeast
Forest Inventory and Analysis Asheville, North Carolina
Forest
Soil Productivity in the Southeast Research Triangle Park, North Carolina
Abstract
Distributional and statistical information associated with stand age, site index, basal area per acre, number of stems per acre, and stand density index is reported for major pine cover types of the Southeastern United States. Means, standard deviations, and ranges of these variables are listed by State and physiographic region for loblolly, slash, longleaf, pond, shortleaf, and Virginia pine cover types. Graphic illustrations of multidimensional relationships among some of the variables are also provided. Bechtold and Ruark 1988. USDA For. Serv. Res. Pap. SE-274.
Key
Words
Southern pine, timberland, pinus, stand structure, forest inventory
Yellow-Poplar: Characteristics and Management
Donald
E. Beck, Lino Della-Bianca
Southeastern
Forest Experiment Station Asheville, North Carolina
Abstract
This reference tool and field guide for foresters and other landmanagers includes a synthesis of information on the characteristics of yellow-poplar with guidelines for managing the species. It is based on research conducted by many individuals in State and Federal forestry organizations and in universities throughout the Eastern United States.
This handbook describes distribution, uses, biological and environmental features, regeneration methods, stand management opportunities, and growth and yield estimates. Beck and Della-Bianca 1981. USDA For. Serv. (Agriculture Handbook No. 583). Agric. Handb. NO. 583. 92p.
Growth and Development of Thinned Versus Unthinned Yellow-Poplar Sprout Clumps
Southeastern
Forest Experiment Station Asheville, North Carolina
Southeastern Forest Experiment Station Asheville, North Carolina Yellow-poplar stump sprouts are capable of very rapid growth and often dominate stands on good sites following harvest cutting. Thinning to one stem per stump at 6 years of age did not affect either height or diameter growth over the succeeding 18 years. The untreated clumps thinned themselves to an average of two stems per clump during the same time period. Thinning to one stem had no apparent effect on butt rot potential from the parent stump, but did reduce the potential for rot from dying ancillary. Beck 1977. USDA For. Serv. Res. Pap. SE-173. 16p.
Key Words
height
growth, diameter growth, butt rot, mortality, fungi, multiple stems, stumps
Board-Foot
and Diameter Growth of Yellow-Poplar After Thinning
Donald
E. Beck, Lino Della-Bianca
Bent
Creek Experimental Forest, USDA Forest Service Southeastern Forest Experiment
Station, Asheville, North Carolina
Board-foot growth and yield of thinned yellow-poplar stands (Liriodendron tulipifera L.) is related to age, site index, residual basal area, and residual quadratic mean stand diameter after thinning. Diameter growth of individual trees is increased considerably by thinning. Equations describing growth and yield are based on data from 141 natura1 yellow-poplar stands in the Appalachian Mountains of Virginia, North Carolina, and Georgia. Beck and Della-Bianca 1975. USDA For. Serv. Se. For. Exp. Stn., Asheville, NC. Res. Pap. SE-123. 20p.
Growth
and Yield of Thinned Yellow-Poplar
Donald
E. Beck, Lino Della-Bianca
U.
S. Department of
Agriculture-Forest
Service Southeastern
Forest Experiment
Station
Asheville, North
Carolina
Abstract
Diameter distributions and yields for various combinations of site index, age, and density for unthinned and largely undisturbed stands of yellow-poplar (Liriodendron tulipifera L. ) have been presented by McGee and Della-Bianca (1967) and Beck and Della-Bianca (1970). Their results were based on the initial measurements of a network of permanent sample plots throughout the southern Appalachians. In this paper we present equations for predicting basal-area growth and cubic-foot volume growth and yield in stands thinned to various levels of basal area. These results are based on measurements of the permanent plots taken 5 years after the initial thinnings. Beck and Della-Bianca 1972. USDA For. Serv. Res. Pap. SE-101. 24p.
Enhancing
a Permanent Sample Plot System in
Natural Forests
Trevor
Beetson, Marks Nester
Queensland
Forest Service, M.S. 483, Gympie QLD 4570, Australia
Jerry
Vanclay
Faculty
of Forestry, Royal Veterinary and Agricultural University, Thorvaldsensvej 57, DK-1871
Frederiksberg C, Denmark
Abstract
Decision
support systems to assist successful forest management are based on growth
models and other prediction techniques. These tools are in turn dependent upon
data derived from permanent sample plots (PSPs). Thus the quality of information
depends on the placement and management of these PSPs. While
existing sample plots may have been adequate in the past, improved technology
and new techniques
have created new possibilities for which these data have proved suboptimal.
Funds for the establishment of additional plots are generally
limited, so supplementary sampling should be based on an optimal sampling
strategy employing prior information. This case study in South-east Queensland
used topoclimatic strata and existing inventory data to identify where
additional PSPs should be established, so as to increase the geographical and silvicultural
range of the growth data collected. Some existing PSPs
in areas
considered
over-sampled may be abandoned.
Estimation of total yield of Douglas-fir by means of incomplete growth series
Begin J
Univ
Laval,Fac Foresterie & Geomat,Quebec City G1K 7P4, PQ, Canada
Schutz JP
Eth Zentrum,Ecole Polytech Fed Zurich,Ch-8092 Zurich,Switzerland
Abstract
This study establishes and validates a method that takes into account yield
levels and permits the reconstruction and modelling of the evolution of total
yield based on incomplete growth series. The calculation of total yield of
Douglas fir (Pseudotsuga menziesii (Mirb) Franco var menziesii Franco) is
carried out by integrating the equation of volume increment per metre dominant
height growth. The model utilized explains 94.8% of the variation in volume
increment per metre height growth of the 14 experimental plots. The evolution of
total yield is calculated for 4 current increment levels. The concept of current
increment levels is similar to the concept of yield levels, and corresponds to
the value of volume increment per metre height growth, at a height of 30 m. At
an equivalent yield level, the calculated total yield curves correspond closely
to those calculated by Bergel (1985). Begin
and Schutz 1994. Ann.
Sci. For. 51: 345-355.
Author
Keywords
total yield, yield level, current increment level, volume increment, douglas fir
Volume
and Weight Tables for Plantation - Grown Sycamore
Roger
P. Belanger
USDA
Forestry Sciences Laboratory Athens, Georgia
Abstract
American sycamore (Platanus occidentalis L.) is well suited for short-rotation management. It can be regenerated easily, has produced excellent early growth on good sites, and lends itself to mechanized harvesting. Steinbeck et al. concluded that spacings of 4 by 4 feet or more and rotation ages from 4 to 10 years hold considerable promise from the standpoints of production, utilization, and management. This paper presents cubic-foot volumes, green weights, and dry weights for the tree sizes expected under these conditions. Belanger 1973. USDA For. Serv. Res. Pap. SE-107. 11p.
A
description of STEMS-- the stand and tree evaluation and modeling system
David
M. Belcher, Margaret R. Holdaway, Gary J. Brand
USDA Forest Service, North Central Forest Experiment Station,1992 Folwell Avenue St. Paul, Minnesota 55108, USA
Abstract
This paper describes STEMS (Stand and Tree Evaluation and Modeling System), the current computerized Lake State tree growth projection system. It presents the program structure, discusses the growth and mortality components, the management subsystem, and the regeneration subsystem. Some preliminary results of model testing are presented and an application is discussed. Belcher, Holdaway et al. 1982. USDA For. Serv. North Cent. For. Exp. Sta. Res. Pap. NC-79. 19p.
Key
words
simulation, Lake States species, mortality model, regeneration model, management guides, growth model, projection system, FORTRAN, validation
Benoit Beliaeff
Ifremer, F-44037 Nantes 01,France
Abstract
Microbiological quality of shellfish production areas along the French coast is
assessed through quantification of fecal coliforms, commonly used as indicators
of fecal pollution. Their concentration is measured in filter-feeding molluscs,
presumed to integrate highly fluctuating quantities of these germs from the
surrounding filtrated water. In the context of a bacteriological monitoring
network, knowledge of contamination spatial structures may help for further
optimal sampling designs. This study aims at applying geostatistical techniques
to describe and characterize the spatial structure of the fecal contamination in
mussels (Mytilus edulis) over a given production area (Havre de la Vanlee,
France), located in macrotidal waters. In comparison with common interpolation
methods, the kriging estimator, a basic tool in geostatistics, presents the
major advantage of providing unbiased estimates with known and minimum
variances. It thus appears to be the most powerful procedure to produce contour
maps for the concentration estimates and their standard deviations. Differences
in mean concentration between the two conducted surveys are compared with
differences in concentration found in continental inputs. Although two surveys
are not sufficient to assess accurately spatio-temporal variabilities, the use
of kriging reveals high spatial heterogeneity, with different structures and
meteorological conditions from one survey to the other. This leads to
questioning the validity of a monitoring based on a few sampling stations over a
large area sampled monthly to estimate a mean bacteriological level. Beliaeff,
Cochard et al. 1995. Wat. Res.
29: 1541-1548.
Author
Keywords
bacteriological monitoring, fecal coliforms, mussel beds, systematic sampling,
spatial structure, kriging, interpolation, mapping, sampling optimization
KeyWords
Plus
ecosystem thau basin, bacterial
Mathematical
programming in forestry
Enoch
F. Bell
Economics of Forest Land Management Project, Pacific Northwest Forest and Range Experiment Station, USDA Forest Service, Portland, Oregon Forest Economics Research, Intermountain Forest and Range Experiment Station, Missoula, Montana
Abstract
Linear programming and its related techniques are increasingly being applied in forestry planning, programming, and budgeting. Caution must be exercised in application to assure that the assumptions accompanying use of the models are not extensively violated. Bell 1977. J. For. 74: 317-319.
Assessment
of regeneration stocking standards used in Alberta: a follow-up
I.E.,
Bella, J.P. DeFranceschi
Northern Forest Research Centre, Canadian Forestry Service Environment Canada, 5320-122 Street Edmonton, Alberta, Canada T6H 3S5
Abstract
This is the second phase of a study conducted to update reforestation standards used in Alberta. The analysis was based on growth and size information of open-growing lodgepole pine (Pinus contorta Dougl. Var. latifolia Engelm.) and white spruce (Picea glauca(Moench) Voss) to estimate the minimum number of well-dispersed trees and stocking percentage required for complete site utilization at reference age of half rotation (40 years for lodgepole pine, 40or 50 years for white spruce). The minimum numbers of well-dispersed trees per hectare required were 575 pine (233.acre) in the Foothills, 610 spruce (247/acre) for sawlog stands in the Mixed wood, 720 spruce (291/acre) for sawlog stands in the Foothills, 900 spruce (364/acre) for pulpwood stands in the Mixed wood, and 1100 spruce (445/acre) for pulpwood stands in the foothills.
Seedling spatial pattern and density were examined in regeneration 10 years after logging, sampled over a wide geographical area in the important forest types of Alberta. Seedling pattern for both species was generally clumpy. Therefore, to ensure at least the minimum required number of well-dispersed seedings on an area, the use of suitably large quadrate (10 m2 or more) and high stocking is necessary. Relationships were developed to show, by stocking percentage classes, the relative frequencies of stocked quadrates with at least 1, 2, 3, etc. seedlings.
Appropriate minimum stocking percentages (by 10 m2 quadrates) derived were 65% for pine, 70 and 80 for spruce sawlog stands in the Mixed wood and the Foothills respectively, and 90% for spruce pulpwood stands. Because the two species have different stocking potentials, procedures are presented for adjusting survey results when regeneration is a mixture of pine and spruce.
Because
of clumping and ingress, the many extra seedlings present on stocked areas
constitute a good reserve of potential crop trees should some of the “first”
seedlings die. However, because present knowledge is rather scanty on mortality
between age 10 and half-rotation age, definitive results must await the
availability of more and better information. Relatively open conditions at
younger ages and generally more open stands on less productive sites implied by
these standards may be advantageous for recreation and wildlife. Bella
and DeFranceschi
Western
gall rust dynamics and impact in young lodgepole pine stands
in
west-central Alberta
I.
E.
Bella, S. Navratil
Northern
Forestry Centre, Canadian Forestry Service, 5320, 122 Street, Edmonton, Alta.,
Canada T6H
3S5
Abstract
A sample of 29 405 lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) trees was assessed from 1982 to 1985, and stem analysis data of 75 trees from five heavily infested second-growth stands in the foothills of the Rockies were analyzed to determine the incidence, development, and impact of western gall rust Endocronartium harknessii (J.P. Moore) Y. Hiratsuka, in relation to age of trees and stand and site factors. The incidence of western gall rust increased with stand age and time. In stands up to 12 years old, the incidence averaged about 5% and increased rapidly to about 20% at age 20. A rapid increase in incidence over time occurred in younger age-classes. In stands 20 years or older, the incidence of new infection was low. Mortality associated with western gall rust among crop trees was low. There was, however, 30% mortality in an unthinned 22-year-old stand over its life. Impact on growth was highly significant (P < 0.01). In the periods 11-15 years and 16-20 years after the wave of heavy infection, reductions in volume growth of infected crop trees were 15 and 25%, respectively. This loss amounts to 15% of the total volume over the 20-year period during which the stands are affected. Western gall rust incidence was higher (p< 0.01) in stands on east-facing slopes than on south- and north-facing slopes. Stands at elevations between 1200 and 1400 m had the highest incidence. Forest management strategies to reduce the impact of western gall rust are discussed, with emphasis on spacing that includes sanitary removal of infected trees. west-central Alberta. Can. J. For. Res. 18: 1437-1442. Bella and Navratil 1988. Can. J. For. Res. 18: 1437-1442.
I.
E. Bella
Northern
Forest Research Centre, Canadian Forestry Service, 5320 122 Street, Edmonton,
Alfa., Canada T6H 3S5
Abstract
In a sample of 121 young lodgepole pine (Pinus contorta Dougl. var. larifolia Engelm.) stands in naturally regenerated cut blocks near Hinton, A h . , strong positive correlations were observed in the incidence of gall rust (Endocronartium harknessii (J. P. Moore) Y. Hiratsuka) and leader damage from terminal weevil (Pissodes terminalis Hopp.) and from pitch twig moth (Petrova spp.) with tree size in both thinned and unthinned stands. Although tests on a selected number of the largest trees from each plot showed no significant differences in incidence of the two pest categories between thinned and unthinned stands, thinning that retains the large trees may result in an Increase in relative incidence of these pests unless special effort is made to cut damaged trees and retain undamaged ones. Bella 1985. Can. J. For. Res. 15: 1008-1010.
Growth of lodgepole pine after mechanical strip thinning in Alberta: 15-year results
I.
E. Bella , J.P. De Franceschi
Northern Forest Research Centre, Canadian Forestry Service Environment Canada, 5320-122 Street Edmonton, Alberta, Canada T6H 3S5
Abstract
An operational thinning in a 25-year-old lodgepole pine (pinus contota Dougl. Var. latifolia Engelm) stand in Alberta resulted in nearly a 50% increase in diameter at breast height (dbh) and height increment in the last 5 years. Initial stands density had no effect on dbh increment beyond that of initial tree size. The release effect extended throughout the narrow (around 1.5 m) leave strips. Mortality continued to occur at about the same rate in both treated and untreated plots, thus reducing the need for follow-up selective thinning. Although the treated area had much lower stand volumes, it has a faster growth rate and may catch up or even surpass the untreated area in merchantable yield at harvest. Bella and Franceschi 1982. For. Chron. 58: 131-135.
Assessment
of regeneration stocking standards used in Alberta
Bella,
I.E., J.P. DeFranceschi
Northern Forest Research Centre, Canadian Forestry Service Environment Canada, 5320-122 Street Edmonton, Alberta, Canada T6H 3S5
Abstract
The
implication of the 40% stocking
standard (by 1-milacre quadrates) that was adopted over a decade ago in Alberta
was examined using data from the Foothills and Mixed wood on regeneration and
expected growth, development, and yield of stands after logging. New minimum
stocking standards were derived for the two most important commercial conifers,
requiring at least 220 well-dispersed
lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) trees per acre
(560/ha), or 300 well-dispersed white
spruce (Picea glauca (Moench) Voss) per
acre (750/ha).
Seedling
spatial pattern for both species was generally clumped. To ensure
the minimum required number of well-dispersed
seedlings on an
area, a larger quadrat should be used in place of the
1-milacre quadratic regeneration surveys. A
10-m2 (1 millihectare, approx. 2.5-milacre) quadrat is suitable for spruce and
12-m2 for pine. The corresponding minimum stocking percentages for
the two species
should be around 75% and 70%, respectively.
While
these recommended minimum numbers of trees may seem low compared to the existing standard, they were derived
t
o ensure full stocking halfway through the
rotation on medium or better sites, thus ensuring acceptable yield at harvest at
a reasonable level of safety.
Open stands on less productive sites may serve other important functions such as
recreation and wildlife habitat.
Problems arising from the present use of stocked quadrat surveys are discussed and recommendations given for further study of the problem. Bella and Franceschi 1976. NFC. Can. For. Serv. Inf. Rep. NOR-X-167. 45p.
Commercial
thinning improves growth of jack pine
I.
E. Bella , J. P. DeFranceschi
Northern
Forest Research Centre, Canadian Forestry Service Department of the Environment,
Edmonton, Alberta
Abstract
Jack pine (Pinus banksiana lamb.) stands
on good sites showed improved tree and stand
growth following
commercial low and crown thinning at age 40.
Data l5
years after
thinning suggest that gross pulpwood and sawlog yields (thinning plus final
yield) will be
greater in treated stands. Growth response to crown thinning occurred
later than response to low thinning, but its effect was of longer duration.
Therefore, on good sites, a combination of low and crown thinning which removes
up to 30-35% of basal area at a stand age of about 40 years may be advantageous
because it reduces thinning costs, improves yield, and lowers harvesting and
processing costs because of increased tree size. Bella and Franceschi 1974. Env. Can., For. Serv.
North. For. Res. Cent. Inf. Rep. NOR-X-112. 26p.
Growth
of young lodgepole pine after mechanical strip thinning in Alberta
I.
E. Bella
Northern Forest Research Centre, Canadian Forestry Service Department of the Environment, Edmonton, Alberta
Abstract
In 25-year-old lodgepole pine (Pinus contorta Dougl. Var. latifolia Engelm.) stands in the foothills, strip thinning stimulated diameter increment, both at breast height and at ground level, of all trees in the dense portions of the stand within five years after treatment. Greatest absolute response in increment was among the larger trees while the small trees showed greater relative response. No significant thinning-response in increment could be established among trees growing under relatively open stand conditions. Because this species seems to respond well to release in dense stands even at age 25, the scheduling of treatment is quite flexible. There was relatively small amounts of drum chopper damage to trees on strip borders and there is no evidence of increase in insect and disease activity. Slash from thinning is decomposing rapidly to the ‘cut’ stripe. Black spruce advanced growth that escaped the chopper blades shows vigorous growth here and will likely form a second story in these stands. Bella 1972. Environ. Can. For. Serv. North. For. Res. Cent. Nor-x-23: 16p.
A
new competition model for individual trees
I.
E. Bella
Northern Forest Research Centre, Canadian Forestry Service Department of the Environment, Edmonton, Alberta
Abstract
The model represents mathematically competitive interaction between individual trees. It consists of two basic components: (1) the influence zone of each tree ( which is a function of its size) and (2) the amount and nature of interaction ( which depends on the distance between and relative size of the competing tree and its competitors and also on a power of relative tree size) . Optimum model parameters were obtained by iterative procedures on a computer, combined with regression analyses for pure, even-aged, fully stocked stands of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), jack pine (Pinus banksiana Lamb.), red pine (P. resinosa Ait.), and aspen (Populus tremuloides Michx.) and for an even-aged stand of Eucalyptus spp. Growing at a range of stand densities. The model satisfactorily described competition effect for the five stands studied and accounted for a greater portion of variation in tree growth than some of the earlier competition indices. Bella 1971. For. Sci. 17: 364-372.
Additional
key words
Tree growth, stand density
Growth
and Survival Modeling for Planted Conifers in the Great Lakes Region
Keith
L. Belli
Faculty
of Forestry, University of Toronto. Toronto, Ontario M5S 1A1, Canada
Alan R.
Ek
Department
of Forest Resources, College of Forestry, University of Minnesota, St.
Paul, MN 55108.
Abstract
In
the steady advance of techniques to model forest systems. The development of
models to
represent the brief, but crucial, establishment phase of planted conifers has
been largely ignored. A framework of prediction equations was developed for
the growth and
survival of red pine and white spruce during the first 5 years after planting. The model development process incorporated data
synthesized from published reports of planting experiments in the Great Lakes
region. Two compatible growth estimation functions were derived to
accommodate
observations of plantation averages in the
form of either
annual stem height increment or total cumulative stem height. A single function was hypothesized for total percent survival. The overall
modeling effort is
a “first
step” in characterizing the regeneration system. Belli and Ek 1988. For.
Sci.
34(2):458-473.
Additional
key
words
red
pine, pinus resinosa.
white spruce, picea
gluaca. planting,
stand establishment.
Relative
stocking index - a proposed index of site quality
William E. Berguson
Natural Resources Research Institute, University of Minnesota at Dultuth, Duluth, MN 55811, USA
David
F. Grigal, Peter C. Bates
Department of Soil Science, University of Minnesota, St. Paul, MN 55108, USA
Abstract
Site index is difficult to implement and interpret in multispecies,
multiple-aged stands, and its relationship to site factors is obscure. Using
data from the USDA forest inventory and analysis (FIA) for the Lake States, we
developed log-log relationships between mean tree size and stand density for
five cover types. Fits were good, with r2 from 0.96 to 0.98 and slopes from
-0.948 to -0.995. We define an alternative index of site quality, the relative
stocking index (RSI), as the ratio of a stand's measured density to that
predicted using the log-log relationship for its cover type (the norm). We
divided the range of RSI into three classes for each type (<0.9 of norm,
>0.91 but <1.1 of norm, and >1.1 of norm). Based on analyses of the
1977 and 1990 FIA data from Minnesota, class assignments for individual stands
remained constant over that 13-year period. Relationships between site factors
and either RSI classes or analogous classes based on site index were examined in
a subset of 169 stands. Temperature, precipitation, silt content of surface
soil, and calculated annual water deficit all differed significantly among RSI
classes, but not among site-index classes. The RSI is easy to apply, robust
(resistant to change), and related to site factors. It merits additional
examination as an index of site quality, especially in heterogenous stands.
Berguson, Grigal et al. 1994. Can.
J. For. Res. 24: 1330-1336.
Keywords
Plus
white spruce plantations, mixed-species stands, nitrogen mineralization,
alternative approach, productivity, soil, density, states, biomass, carbon
Effect of rotation length on productivity of aspen sucker stands
A.
B. Berry
and W. M.
Stiell
Petawawa
Forest Experiment Station Chalk River, Ontario
Abstract
Repeated
harvesting of young aspen sucker stands at the Petawawa Forest Experiment
station indicated that biomass prediction cannot be sustained on rotations of up
to ca 10 years for longer periods are not yet available but growth trends at
least 15 years as the minimum rotation age. Berry and Stiell 1978. For. Chron. 54: 265-267.
Berry
AB
Petawawa
Forest Experiment Station Chalk River, Ontario
Abstract
Yield
tables for high survival unthinned red pine plantations were updated and revised
to present the data in metric units. Tables
present the data from 20 to 50years from planting, by 5-year age classes, for
eight planted spacing and five site index classes. Each table shows the number
of trees, basal area, total volume, and merchantable volume per hectare and the
mean dbh for each age and spacing. Site index curves are also presented. Berry
1977. Fish. Envir. Can., For. Serv. Inf. Rep. PS-X-65.
18-Jan.
Huiquan Bi
State
Forests NSW, Res & Dev Div, POB 100, Beecroft, NSW 2119, Australia
Abstract
This article introduces a generalized expression of the self-thinning rule, B =
(KSNbeta)-N-alpha, where B is stand biomass per unit area, N is stand density, S
is relative site index, and K, alpha and beta are parameters. On log scales,
this equation becomes a self-thinning surface that defines a density-dependent
upper frontier of stand biomass over a gradient of site productivity for a given
species. This equation is formulated for parameter estimation as a stochastic
frontier function with two error components that have different distributional
properties. As an example, maximum likelihood estimates of the self-thinning
surface and its confidence envelope were shown for Pinus radiata (D. Don).
Furthermore, site occupancy was estimated through one of the error components of
the stochastic frontier function. The conditional response of mortality at any
given site occupancy was revealed by using regression quintiles. Light mortality
was associated with increases in site occupancy, while heavy mortality caused a
reduction in site occupancy. Changes in the estimated site occupancy had a
linear relationship with changes in log stand density. The dynamic interplay
between site occupancy and mortality, together with the random external effects
on the self-thinning frontier, was suggested to drive the growth trajectories of
individual stands during stand growth and self-thinning. Consequently,
individual stands seldom travel along their self-thinning frontiers but are more
likely to converge toward them during the self-thinning phase of stand
development. Bi 2001. For. Sci. 47: 361-370.
Author
Keywords
stochastic frontier function, site productivity, site occupancy, mortality
regression quintile, stand dynamics, Pinus radiata
Keywords
Plus
Density Management
Diagrams, Pinus-Taeda Plantations, Quintile Regression, Stand Density,
Plant-Populations, United-States, Jack Pine, Competition, Rule, Radiata
Flexible taper equation for site-specific management of Pinus radiata in
New South Wales, Australia
Huiquan Bi, Yushan Long
Forest Reserch and Development Division, State Forests of NSW, P.O. Box 100, Beecroft, NSW 2119, Australia
Abstract
A trigonometric variable-form taper equation has been developed for P: radiata
using data from 3251 trees sampled across plantation sites in New South Wales.
Australia. The equation predicts relative stem diameter with little local bias
within any stem sections, and the 90% confidence interval of prediction error is
within +/-0.1 over the entire stem. Evaluation of prediction accuracy over 10
diameter classes shows that the local bias of relative diameter prediction is
mostly within +/-0.015 within any stem section. The most biased and the least
precise predictions were found for small trees with overbark diameter at breast
height less than 18.3 cm. There was little bias in the estimation of
merchantable height at any specified top end underbark diameter ranging from 5
to 40 cm using the taper equation. The average size of error of merchantable
height estimation was less than 1 m for top end diameter limit less than 20 cm
and slightly greater than 1 m beyond this range. When compared against the nine
site-specific compatible polynomial taper equations currently used in forest
management across the nine site strata, the trigonometric variable-form taper
equation generally provides more accurate predictions of relative diameter,
although the former is a single function and the later consists of nine separate
site-specific equations. The flexibility and predictive performance of the
trigonometric variable-form taper function should eliminate the needs of
developing potentially a large number of site-specific compatible polynomial
taper functions, particularly with increasingly refined definition of sites for
P. radiata under site-specific management in New South Wales. Developing more
general yet flexible trigonometric variable-form taper functions for P. radiata
will prove to be more cost-efficient. Bi and Long 2001. For. Ecol. Manage. 148:
79-91.
Author
Keywords
trigonometric variable-form taper function: prediction accuracy, model
comparison, site-specific management
Keywords
Plus
stem form
Biester H, Muller G, Scholer HF
Institute
of Environmental
Geochemistry, University
of Heidelberg, INF 236, D-69120 Heidelberg, Germany
Abstract
Mercury emissions from chlor-alkali plants have been past and present sources of
soil contamination with Hg. Here we calculate net mercury (Hg) deposition to
soils in the vicinity (100-1000-m downwind) of three-chlor alkali plants.
Calculations were based on spatial distribution patterns of Hg concentrations in
soils, which were extrapolated by kriging. Moreover, we investigated to what
extent Hg deposition depends on the elevation of receptors and canopy through fall. Mercury concentrations in soil exceed backgound values up to a
factor of 56 and show enrichment factors between 2 and 5.8 calculated from the
median Hg concentration. Net deposition rates range between 2356 and 8952 mug
m(-2) year(-1) which is up to 224-fold the background values. Net deposition of
Hg to soils at the three sites varies between 1.2 and 2.4% of total emitted Hg.
Highest deposition rates were found at sites with extended elevated or forested
areas. Here, Hg concentrations in soils increased by a factor of up to 7.3 in
elevated (+ 180 m) forest areas compared to non-elevated Grassland soils.
Biester,Muller et al. 2002. Sci.
Total Environ. 284: 177-189.
Author
Keywords
chlor alkali plants, mercury, soils, Hg deposition rates, Hg retention
KeyWords
Plus
elemental mercury, chloralkali plant, deposition, pollution, forest, dry
Estimating the accuracy of volume equations using taper equations of
stem profile
Greg
S. Biging
Department of Forestry and Resource Management, University of California at Berkeley, Berkeley, CA 94720, USA
Abstract
Comparison of log volume estimation techniques are performed using the equations of Smalian, Huber, and Newton, and a numerical technique using cubic splines. The data utilized were obtained by predicting diameters at various points along the stem from two pater equations for white fir. Results indicate that Newton’s and Huber’s equations were the most accurate, followed by the cubic spline and Smalian’s equation, respectively. This technique facilitated partitioning of the total error in volume estimation into measurement error and error due to model misspecification arising when the taper of logs could not be exactly described by a simple model such as a frustum of a paraboloid. For the taper relationships analyzed it was shown that the error due to the selection of an inappropriate mensurational model is less than 5%for a measurement distance of 16 ft (4.9 m) for all models tested and can be substantially reduced by applying the formulate only to logs positioned above basal swell. Systematic measurement error was assessed analytically and found to range between 1 and 4%. Thus, total error in volume estimation was less than 9%for all methods tested. Biging 1988. Can. J. For. Res. 18: 1002-1007.
Improved
estimates of site-index curves using a varying-parameter model
Greg S. Biging
Univ Calif. Berkley, Dept Forestry & Resource Management, Berkley, CA 94720,USA
Abstract
Current methods
for developing site index curves from stem analysis data or from remeasured
permanent plots commonly regress height on age (or age
and site) using a nonlinear regression model fitted to the pooled observations.
While this is a computationally
efficient method, it does not satisfactorily account for between-tree
differences in individual tree height growth. This paper presents a
varying-parameter (linear random regression coefficient) model that is derived by fitting height growth models to each individual tree in the
data set A
weighted least squares technique is
then employed to
combine these
individual estimates to
mean estimate of the parameters of
a sigmoid
height growth model. These parameters are then used to
predict the height development of site
trees. An example
of the procedure
is given
using stem analysis data
from primarily
dominant trees in the young-growth mixed conifer forests of California.
Biging 1985. For.
Sci. 31:248-259.
Additional
key words
Stem
analysis data, sigmoid model, height growth.
Taper equation for second-growth mixed conifers of northern California
Greg S. Biging
Univ. Calif. Berkley, Dept Forestry & Resource Management, Berkley, CA 94720,USA
Abstract
This
paper presents a taper equation derived from the Chapman-Richards function to
describe stem form for second-growth mixed conifers in Northern California. The
primary use of the models is for predicting upper stem diameters as a function
of relative height and DBH. Additionally, these models can be used to create
volume tables to any merchantable top diameter. Biging 1984. For. Sci. 30: 1103-1117.
Additional
key words
Chapman-Richards
function, Mixed confier forests.
Dan Binkley
School of Forestry and Environmental Studies Duke University, Durham,
NC, USA, 27706
Pual Reid
Department of Forest Science, Oregon State University, Corvallis, OR.
USA, 97331
Abstract
Within a 53-year-old Douglas-fir(Psuedotsuga mensiesii (Mirb.) Franco) plantation, replicated thinning and fertilization plots were examined for responses in stem growth, leaf area, and stem growth per unit leaf area. Although measurements occurred 20-30 years after plot installation, substantial effects from the various treatment levels were still present. Thinning reduces leaf area of the stands but increased stem growth per unit of leaf area, resulting in little difference in stem growth per hectare over the 5-year measurement period (1977-1981). Fertilization increased both stand leaf area and stem growth per unit leaf area, and more than doubled 5-year stem growth per hectare, Consideration of the role of leaf area and stem growth per unit leaf area in determining stand treatment responses may account for much of the variation found among replicates of treatments or between studies on different sites. Binkley and Reid 1984. Can. J. For. Res. 14: 656-660.
Volume sampling using indirectly estimated critical heights
Walter
Bitterlich
Abstract
A method is described for making practical use of kitamura’s method of estimating volume per hectare as the sum of “ critical heights” multiplied by the angle count factor (=” basal area factor”), the critical point being defined as the point up each selected tree stem which is exactly covered by the chosed relascope angle (as viewed from the sampling point) in an angle count sample. It is generally too difficult to locate the critical point by actual measurements. Instead, its height is to be obtained from a taper function computed for the species and locality. This function is put in a convenient form, as the “critical height function”, which requires only the breast height diameter in relative units (“ relascope units”) and the total height in meters, to give the critical height of each sample tree in metres. Suitable approximate functions can be derived by computer from data already recorded, or from data specially collected, for example by using the new Telerelaskop. A pocket programmable computer can the be used, with the appropriate critical height function incorporated in this program, and with data easily obtained using a “wide scale” Relaskop (or even with calipers, tape and any kind of “hypsometer” or clinometers) to compute the critical heights, and hence the volume per hectare. It is further shown that the data collected give very simple methods for computing various weighted stand indices. Viz. Lorey’s stand height, stand form height, and stand form factor. The individual critical heights can also be sued as “volume weightings” to allocate total volume estimates to assortments, quality classes, etc. The weightings can also be sued when testing or correcting the local critical height functions themselves, so that the system is capable of continuous refinement. Commonw. Bitterlich 1976. For. Rev. 55: 319-334.
John Blake, Greg Somers
Auburn Univ, Sch Forestry,108 M White Smith Hall,Auburn,Al
36849 Auburn Univ, Agr Expt Stn,Auburn,Al 36849
Greg Ruark
US Forest Serv, Soils Product Res,Res Triangle Pk,NC
Abstract
The ability of forest stands to sustain increasing amounts of foliage biomass is
related in a positive manner to both aboveground woody biomass and to site
productivity. Knowledge of the limit to sustainable foliar biomass at a given
level of photosynthetically active radiation and under minimum environmental
stress would have important implications for modeling primary forest
productivity. Theoretical analysis and limited experimental data collected on
even-aged plant populations that are undergoing self-thinning indicate that
total stand foliar biomass should achieve a nearly constant value for a given
species and site. Average diameter-plant density relations for various conifers
species coupled with available foliage mass-stem diameter equations were used to
approximate the maximum amount of foliage which could be sustained. Source of
bias and effects due to changes in specific leaf area are evaluated. The maximum
foliage biomass calculated in this manner was subject to positive bias, but
estimates at low densities correspond to values obtained empirically for mature
stands growing under very favorable environmental conditions. Calculated
estimates suggest that maximum sustainable foliage biomass increases slightly
with decreasing plant density along the self-thinning line, in contrast to
expectations. The magnitude of the increase depends upon the relative value of
the self-thinning exponent compared to the exponent of the allometric equation.
Changes in light distribution in relation to crown architecture, particularly
crown depth and foliage clustering, may account for this effect. Blacke, Somers
et al. 1991. For. Sci. 37:
296-307.
Author
Keywords
loblolly pine, radiata pine, Douglas-fir, light, mortality
KeyWords
Plus
loblolly-pine, leaf-area, Douglas-fir, rule, stem
Kristina Blennow
Southern
Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Box
49, SE-230 53 Alnarp, Sweden
Lars
Lindkvist
County
Forestry Board West Sweden, Environmental Unit, Box 343, SE-503 11 Bora s,
Sweden
Abstract
Low temperature during the growing season is known to be a leading cause of
stress and damage to tree seedlings and interactive effects with high irradiance
have been recognised as enhancing the damage. Spatial variation in low
temperature and irradiance for mountainous terrain was, therefore, hypothesised
to give rise to spatially variable potential for regeneration of tree seedlings
and expansion of forest. Combined exposure to low temperature and high
irradiance appears most likely on clear mornings following frosty nights.
Geographic information system-based models of the spatial variation in minimum
air temperature over clear-felled terrain and potentially intercepted direct
radiation energy were constructed and were used together with measured values of
minimum air temperature to explain observed spatial variation in mortality rates
for planted tree seedlings in central Sweden. A local-scale multiple regression
model explained 78% of the measured spatial variability in minimum air
temperature over 625 km(2) and a corresponding, but univariate, microscale model
explained 54% of the measured spatial variation in minimum air temperature over
4 ha. Multiple logistic regression models for the mortality rates of seedlings
showed there was no significant effect of potentially intercepted amounts of
direct radiation energy during the morning for either scale. There was, however,
a significant effect (p<0.0001) of measured minimum air temperature on
seedling mortality rates for the microscale study, but no corresponding
significant effect for the local-scale study. This confirms that low temperature
is an important determinant for seedling mortality. It is likely that other
factors than low temperature may be important. However, our results indicate
that effects of local-scale variability in minimum air temperature, represented
by the minimum air temperature at standard height above the ground (1.8 m), may
be over-shadowed by minimum air temperature variability at seedling height in
complex terrain. This has implications for the use of standard meteorological
data for studies into the responses of plants to abiotic factors. Blennow and
Lindkvist 2000. For. Ecol.
Manage. 135: 289-301.
Author
Keywords
seedling mortality, minimum air temperature, photoinhibition, light stress,
logistic regression, solar radiation, regeneration, risk map, frost damage,
frost
KeyWords
Plus
cold-induced photoinhibition, frost damage, snow gum, photosynthesis, elevation,
forests, spruce, field, line, GIS
Riparian
management practices---a summary of state guidelines
Charles
R. Blinn, Michael A. Kilgore
Forest
Management, University of Minnesota, 1530 Cleveland Avenue North, St. Paul, MN
55108;
Abstract
Individual
states develop guidelines to protect and manage forest riparian resources. A
review of 49 states’ forest riparian guidelines revealed the primary focus is
to protect the quality of water adjacent to perennial and intermittent streams
and lakes. A commonly recommended riparian management zone is 50 feet wide with
50 to 75 percent crown closure (or 50–75 square feet per acre of residual
basal area); however, the specific guidelines in each state vary tremendously.
Although science cannot specify the management prescriptions needed to protect
all riparian functions across all sites, understanding site-specific conditions
is critical to effective guideline implementation. Blinn and Kilgore 2001. J. For. 99: 11-17.
A lognormal approach to diameter distributions in even-aged stands
Bliss CI, Reinkier KA
The Conneticut Agric. Expt. Sta. And Dept. of Statistics, Yale University, New Haven Conn. USA
Abstract
Diameter
distributions of Douglas-fir can be described by the empirical three-parameter
lognormal curve, in which the variate is y=log(y`+y0`).
Following a description of both a graphic and a numerical solution for the
origin or third parameter y0`, the logarithm of the origin is
shown to be a linear function of the logarithm of the initial mean dbh (y`)
in a series of 16 distributions. Given the predicted origins y0`,
the means and standard deviations of y=log(y`+y0`) are simple
function of log y`, Agreement between the observed and the expected
frequencies is tested by x2. Bliss and Reinkier. 1964. For.
Sci. 10: 350-360.
Living
stands and dead wood in the Bialowieza forest: suggestions for restoration
management
Andrzej Bobiec
Bialowieza National Park, Park Palacowy 5, 17-230 bialowieza, Poland
Abstract
The Bialowieza Primeval Forest (BPF) is the only forest area in temperate Europe
where forest communities have developed a natural stand structure and a natural
distribution of coarse woody debris ((CWD) = standing dead trees (SDT) + down
woody material (DWM)). Stand and dead wood characteristics are influenced by
ancient and recent historical factors and current processes, such as fires,
competitive exclusion, storms, insect outbreaks, and forest management. The aim
of the present study was to relate CWD to stand characteristics in mesic
deciduous forest (Tilio-Carpinetum JQ) and riparian forest (Circaeo-Alnetum
(CA)). Direct comparison of managed forest to protected forest provides
information about the impact of the forestry practices on TC stand and CWD
characteristics. Approximately two-fold larger volume of trees was found in the
Bialowieza National Park (BNP) TC stands (from 336 to 555 m(3) ha(-1)) than in
the commercial forest ((CF), from 239 to 279 m(3) ha(-1)). Irregular
distribution of "legacy trees" (DBH > 90 cm) accounted for most of
the variability among the TC BNP stands. Even stronger differences within TC
stands were revealed among the various developmental phases (from 147 m(3)
ha(-1) in degradation phase to 630 m(3) ha(-1) in biostatic-optimal phase).
Difference in rate of stand development was responsible for the variability of
tree volume within CA (338 m3 ha-1 in early succession stand versus 634 m(3)
ha(-1) in close-to-climax stand). CWD (mostly DWM) contributed about one-quarter
of the total above ground wood biomass in BNP TC and CA ecosystems, ranging from
87 to 160 m(3) ha(-1). Higher relative abundance of spruce in DWM than in living
stand volume and more spruce in old debris than in fresh debris suggests that
the end of the spruce mortality wave was imminent. As a consequence, structural
and dynamic changes in favour of smaller regeneration units are expected. A mere
vestige of CWD was found in the CF ecosystem. Both stand and CWD data show a
negative impact of former management on the forest ecosystems. In conclusion,
special measures aimed at the restoration of ecological capacity of forest
communities, including legacy retention and management for decadence, have been
recommended. There is an urgent need for complementary studies to supply
information necessary for successful adaptive management of the Bialowieza
Primeval Forest.
Bobiec 2002. For. Ecol. Manage. 165: 125-140.
Author
Keywords
Bialowieza Primeval Forest, coarse woody debris, developmental phases, forest
dynamics, forest management, legacy trees, restoration management
KeyWords
Plus
dynamics, debris, conservation, biodiversity, Newfoundland, disturbance,
ecosystems, age
Kriging and thin plate splines for mapping climate variables
Eric
P J Boer, Kirsten M de Beurs
Wageningen
University and Research Center, Mathematical and Statistical Models Group,
Dreyenlaan 4, 6703 HA Wageningen, The Netherlands
A
Dewi Hartkamp
Natural
Resources Group, International Maize and Wheat Improvement Center (CIMMYT),
Lisboa 27, Apartado Postal 6-641, 06600 Mexico D.F., Mexico
Abstract
Four forms of kriging and three forms of thin plate
splines are discussed in this paper to predict monthly maximum temperature and
monthly mean precipitation in Jalisco State of Mexico. Results show that
techniques using elevation as additional information improve the prediction
results considerably. From these techniques, trivariate regression-kriging and
trivariate thin plate splines performed best. The results of monthly maximum
temperature are much clearer than the results of monthly mean precipitation,
because the modeling of precipitation is more trouble some due to higher
variability in the data and their non-Gaussian character.
Boer, de Beurs et al. 2001. JAG. 3: 146-154.
Ralph E.J. Boerner,
Amy J. Scherzer, Jennifer A. Brinkman
Department of Plant Biology, Ohio State University, 1735 Neil Avenue,
Columbus, OH 43210 USA
Abstract
This study quantified intersite variation and spatial pattern in organic C content, total
inorganic N and extractable inorganic P in soils among six sites
constituting a post-disturbance chronosequence in southwestern Ohio, USA. The
study sites included an agricultural field with a 25 + yr history of soybean
cropping (chronic disturbance), a site which had been stripped of its surface
soil and reclaimed using post-mining procedures (pseudo-stripmine, acute
disturbance), 5 and 10 year old fields, a 25-30 year old prairie restoration,
and an undisturbed, mature forest. All six sites were on soils with similar
texture and classification. With the exception of the active soybean field, P
and organic C increased with time since disturbance. Inorganic N was high in the
soybean field and mature forest and low in the other four sites, with no
consistent temporal trend. Spatial dependence of inorganic N and organic C were
high in most sites and decreased with time since disturbance. Spatial dependence
of P was lower than those of inorganic N and organic C and did not exhibit any
clear temporal trend. Each nutrient exhibited its own unique spatial and
temporal pattern of variation, and correlations among resources were weak. The
results emphasize the need for quantifying and understanding spatial patterns as
a prerequisite for developing restoration planting protocols or operationalizing
mechanistic models predicting vegetation change in specific study sites. Boerner,
Scherzer et al. 1998. Appl. Soil Ecol. 7: 159-177.
Author
Keywords
nitrogen, phosphorus, organic carbon, reclamation, semivariance analysis,
spatial pattern, succession
KeyWords
Plus
forest, geostatistics, mycorrhizal, variability, ecology, plants, long
GSLIB-style programs for discriminant analysis and regionalized classification
Geoffrey C.
Bohling
Kansas
Geological Survey, 1930 Constant Avenue, Campus West, Lawrence, KS 66047-3726
Abstract
Discriminant analysis is a statistical technique used to predict the group
membership of a set of multivariate observations, each of which is assumed to
arise from one of a set of distinct classes or groups. Each group is
characterized by a certain distribution in multivariate space, and group
allocations are based on the similarity of each sample to each group. Assuming
multivariate normality, generalized distance measures based on the squared
Mahalanobis distance from each sample to each group centroid arise as the
natural measure of similarity. One can allocate samples to groups either on the
basis of minimum generalized distance or, equivalently, maximum posterior
probability of group membership. In earth science applications samples are often
associated with geographic locations. In this situation regionalized
classification can be used to produce a map representing group membership
throughout the sampled domain. This can be accomplished by interpolating either
generalized distances or membership probabilities from sample locations to
regularly spaced grid nodes and comparing resulting grids to produce a
classification map. This paper presents a set of GSLIB-style FORTRAN programs
for performing discriminant analysis and regionalized classification. The
program disco performs discriminant analysis and the programs xmd2cls and
prb2cls combine interpolated distances and probabilities, respectively, to
create a grid of predicted classifications. In addition, the utility program
colbind allows the user to combine selected columns from different GSLIB-style
data files into one file. Bohling 1997. Comput. Geosci. 23: 739-761.
Author
Keywords
discriminant analysis, regionalized classification, geostatistics, FORTRAN
Forest
productivity, leaf area, and terrain in southern Appalachian deciduous forests
Paul V. Bolstad
Department
of Forest Resources, University of Minnesota, 1530 Cleveland Ave. N., St. Paul,
MN 55108
James
M. Vose
Coweeta
Hydrologic Lab, USDA Forest Service, 3160 Coweeta Lab Rd., Otto, North Carolina
28763.
Steven
G. McNulty
Southern
Forest Experiment Station, USDA Forest Service, 1509 Varsity Dr., Raleigh, NC
27606.
Abstract
Leaf area index (LAI) is an important structural characteristic of forest
ecosystems which has been shown to be strongly related to forest mass and energy
cycles and forest productivity. LAI is more easily measured than forest
productivity, and so a strong relationship between LAI and productivity would be
a valuable tool in forest management. While a linear relationship has been
observed between LAI and forest productivity, most of these data have been
collected in needle-leaved evergreen stands. The generality and consistency of
the relationship between LAI and productivity has not been as well established
for deciduous forests.
Leaf area index (LAI) and aboveground net primary production (ANPP) were measured on 16 forest stands in the southern Appalachian Mountains. These stands span a range of elevation, slope position, temperature, and moisture regimes. LAI averaged 5.8 m(2) m(-2) and ranged from 2.7 to 8.2. ANPP averaged 9.2 Mg ha(-1) yr(-1) and ranged from 5.2 to 11.8 Mg ha(-1) yr(-1).
LAI and ANPP decreased significantly from cove to ridge sites, and ANPP decreases significantly from low to high elevation (P < 0.05, linear regression slope). Elevation-related differences in ANPP do not appear to be due to changes in precipitation, leaf nitrogen content, or site N mineralization rates.
Linear ANPP-LAI equations fit to the data measured in this study were significant (P < 0.05). These relationships were not significantly different (P > 0.1) from linear relationships based on data reported in most other studies of ANPP and LAI in eastern deciduous forests of North America. However, the slope of a linear regression model based on North American eastern deciduous forests was significantly different (P < 0.05) from one based on data collected in temperate deciduous forests for the rest of the globe. The differences were slight over the range of observed data, however, and the difference may be due to a narrower range of data for North American deciduous forests. Bolstad, Vose et al. 2001. For. Sci. 47: 419-427.
Author
Keywords
ANPP, LAI, precipitation, temperature, elevation
KeyWords
Plus
net primary production, oak forest, biomass, nitrogen, index, soil, wisconsin,
carbon, ecosystems, allocation
Paul V. Bolstad
Forest
Resources, University of Minnesota, 1530 N. Cleveland Ave, St. Paul, MN 55108,
USA
Lloyd
Swift
Coweeta
Hydrologic Lab, US Forest Service, Otto, NC 28763, USA
Fred
Collins
Resource
Management and Distributed Systems, IBM, Boulder, CO 80301, USA
Jacques
Regniere
Natural
Resources Canada, P.O. Box 3800, Sainte-Foy Que, Canada G1V 4C7
Abstract
Landscape and temporal patterns of temperature were observed for local (13
station) and regional (35 station) networks in the southern Appalachian
Mountains of North America. Temperatures decreased with altitude at mean rates
of 7 degrees C/km (maximum temperature) and 3 degrees C/km (minimum
temperature). Daily lapse rates depended on the method and stations used in the
calculations. Average daily temperature ranges decreased as elevation increased,
from 14 degrees C at 700 m to 7 degrees C at 1440 m, and daily temperature
ranges were typically higher in spring and fall at any given station. Daily
maximum temperatures above the forest canopy averaged 1.4 degrees C higher at a
south-facing station relative to a comparable northwest-facing station, and
above-canopy daily minimum temperatures were depressed at a valley-bottom
station. Regional regression models provided a more accurate estimates of
station temperature than either kriging or local lapse models when tested using
35 National Climatic Data Center (NCDC) stations in the southern Appalachians.
Data-splitting tests yielded mean absolute errors (MAE) from 1.39 to 2.30
degrees C for predictions of daily temperatures. Ten-year biases for an
independent data set collected at four stations in the Coweeta Basin ranged from
-2.87 to 2.91 degrees C for daily temperatures, with regional regression
performing best, on average. However tests against another independent data set
indicate regional regression and local lapse models were not significantly
different, with mean biases averaged from -2.78 to 2.91 degrees C for daily
predicted temperatures. Bolstad, Swift et al. 1998. For. Meterorolgy. 91: 161-176.
KeyWords
Plus
gypsy-moth lepidoptera, climate-change, model, evapotranspiration,
photosynthesis, simulation, management, phenology, events, soil
Projecting stand and stock tables: a comparison of three methods
Bruce
. E. Borders
School
of Forest Resources, University o f Georgia, Athens, Georgia, USA
Abstract
Often, it is desired to project an existing stand and stock table to a future age in even-aged stands. There are several alternative procedures available to modelers to accomplish this goal. Below, I compare and contrast three such procedures for projecting stand and stock tables for loblolly pine (pinus taeda L.) plantations grown in the southeastern United States. One procedure is a Weibull parameter recovery model, another is a distribution free percentile-based algorithm, and the third uses an individual tree distance independent basal area projection model.
Each projection procedure was fitted to a large loblolly pine database. Statistics of fit for the fitted database and an independent database were generated for number of trees by diameter class, volume by diameter class, and volume by product class. The procedure based on the individual tree distance independent basal area projection model was superior to the other tow modeling procedures for mode of the fit statistics.
Keywords:
Growth and yield, stand table projection
Systems of equations in forest stand modeling
Bruce E. Borders
School
of Forest Resources, University o f Georgia, Athens, Georgia, USA
Abstract
Growth
and yield models are often composed of systems of related equations. Parameter
estimation techniques such as two-stage and three-stage least squares have been
suggested for fitting such systems. An alternative theoretically sound parameter
estimation procedure that can be sued for any number of sequentially related
equation, linear and nonlinear, is presented and discussed. Implementation of
this procedure is illustrated for two systems of equations. Borders 1989. For. Sci. 35:
548-556.
Additional
key words
Instrumental
variables, Zellner estimation, multistage regression
Diameter-based
biomass regression models ignore large sapwood-related variation in Sitka spruce
B.
T. Bormann
USDA
Forest Service, Pacific Northwest Research Station, 3200 Jefferson Way,
Corvallis, OR 97331, U.S.A.
Abstract
Precise estimates of biomass are needed in productivity and nutrient cycling studies, and for improved estimates of potential productivity. Improvements in prediction of foliage and branch biomass were sought by comparing multiple regression models using stem diameter, sapwood radial thickness, and tree height as independent variables in stands of Sitka spruce (Picea sitchensis (Bong.) Carr.) in southeast Alaska. Five sites were sampled by stratifying trees into four diameter and three sapwood-thickness classes. Within stands, sample trees with thick sapwood consistently had 2-3 times more foliage and branch biomass than paired trees with thin sapwood but nearly equal diameter. Inclusion of both diameter and sapwood thickness in equations increased precision of foliage and branch biomass, leaf area, and net primary productivity by 15-31% and reduced standard error by 35-48% when compared with equations containing only diameter as an independent variable. Height growth over the last 30 years of intermediate and codominant trees with thick sapwood was 12-27% greater than that of paired trees with thin sapwood but nearly equal diameter at breast height. The addition of total tree height to multiple regression models, however, had little effect on their precision. Stem biomass equations were not improved by including tree height or sapwood thickness. The use of a diameter - sapwood thickness sampling matrix for construction of biomass equations may reduce the sample size needed and result in equations with wider application. Bormann 1990. Can. J. For. Res. 20: 1098-1104.
Maximizing information from a water quality monitoring network through
visualization techniques
Boyer JN, Sterling P, Jones RD
Southeast
Environmental Research Center,
Florida International University, Miami, FL 33199, U.S.A.
Abstract
This paper describes a variety of visualization techniques that have been very
useful for demonstrating important aspects of a water quality monitoring
programme in South Florida. The first level of visualization was at the single
station or grouped stations using the box-and-whisker plot as a
graphical/statistical tool. This plot was used to compare intra-annual
variability and correlation between total phosphorus (TP) and chlorophyll a (chl
a) at a site in Florida Bay. Secondly, time was added as a dimension to produce
a 9-year, monthly time series plot of declining salinity at a site in NE Florida
Bay. It was shown how a centred moving average could be used to smooth out the
noise and disclose inter-annual oscillations. Time series of anomalies from long
term means were discussed as a means of displaying correspondence and coupling
among variables. Thirdly, the utility of 2-D contour maps of variables was
demonstrated in showing sources and mixing of fresh water across the hydroscape
as well as nutrient loading to the South Florida ecosystem. From this expanded
spatial view, it was observed that the water quality of different bays and
coastal areas are differentially affected both by external and internal
processes and how management of pump operations and canal conductance can
overwhelm the natural hydrological cycle and have far reaching impacts in
Florida Bay and the SW Florida Shelf. We also showed that contouring was useful
for elucidating causal relationships among variables over the spatial domain.
Time step animations of monthly salinity contours in Florida Bay showed the
importance of mixing with western boundary waters to alleviation of hypersaline
conditions. These animations also showed that it is the shifting lags between TP
concentration and chi a which make it so difficult to derive a simple regression
model. Finally, a 3-D volumetric rendering of the area between Key West and the
Tortugas was used to describe a strong density stratification event during July
1998 and to visualize the source of water masses and general circulation
patterns in this region. It is concluded that visualization techniques are
useful not only to show patterns in the data but in developing new hypotheses
for future research and monitoring activities. Boyer, Sterling et al.
2000. Estuar. Coast. Shelf Sci. 50:
39-48.
Author
Keywords:
water quality, estuary, geostatistics, salinity, nutrients, chlorophyll, Florida
Bay, coral reef, management
KeyWords
Plus
florida-bay, keys
Variations in height-over-age-curves for young longleaf pine plantations
William
D. Boyer
George
W. Andrews Forestry Sciences Laboratory, Auburn, Alabama, maintained by the
Southern Forest Experiment Station, USDA Forest Service, in cooperation with
Auburn University
Abstract
Some environmental factors related to height growth of longleaf pine (Pinus Plaustris Mill.) plantations were identified by analyses of data from remeasured plots. A total of 660 plots, mostly from the South wide Pine Seed Source Study, provided 2,737 height-over-age observations from age 3 thought ages 15 or 20 to 22. A single variable equation derived from all observations, Log10 (Height)=b0+b1(Age)-1, was fitted to each plot. Slope coefficient (b0) from individual plots became the dependent variable for analyses to determine association of height growth patterns with recorded site and stand variables, Seventy percent of slope coefficient variation among 32 seed-source plantings was accounted for by classification of planting site into (1) old fields (2) mechanically prepared cutover sites, and (2) unprepared cutover sites. Among plots, coefficient values were significantly related to stand density, site quality, and seed source. Results indicate the need for a series of polymorphic plantation site-index curves, or growth models, that take into account important site-specific variables affecting early height growth. Boyer 1983. For. Sci. 29: 15-27.
Additional
key words
Pinus plaustris, site index, site quality, stand density, site preparation, height growth
Interim site index curves for longleaf pine plantations
George W. Andrews Forestry Sciences Laboratory, Auburn, Alabama, maintained by the Southern Forest Experiment Station, USDA Forest Service, in cooperation with Auburn University
No single set of site-index curves can be uniformly applied to young longleaf pine plantations without a sacrifice in reliability. A recent study using plantation remeasurement data indicated that planting-site condition (old fields and mechanically prepared or unprepared cutover forest sites) has a major impact on early plantation height growth. Stand density (surviving trees per acre) also affected form of height-over-age curves. On both prepared and unprepared forest sites, site quality affected curve form, so polymorphic site-index curves resulted for these two conditions. Longleaf pine plantation site-index curves for these three planting-site conditions were derived from 660 plots remeasured through ages 15 to 17 or 20 to 22 years. Modification of the curves may be necessary as more data become available. Boyer 1980. USDA For. Serv. Res. Pap. SO-261. 5p.
Site and stand factors affecting height growth curves of longleaf pine
plantations
George W. Andrews Forestry Sciences Laboratory, Auburn, Alabama, maintained by the Southern Forest Experiment Station, USDA Forest Service, in cooperation with Auburn University
Abstract
Some factors related to the form of height-over-age curves in longleaf pine plantations were identified from analyses of 660 periodically remeasured plots. Seventy percent of the variation among 32 plantations in form the growth curve was accounted for by stratifying planting sites into old fields, mechanically prepared and unprepared cutover sites. Curve form was affected by site quality on prepared and unprepared site, and by stand density on all sites. Boyer 1980. P.184-187. Proc. First Biennial south. silv. res. Conf., 1980.
Influence of spacing on growth of red pine in plantations
Bramble, W.C., H.N. Cope, H.H. Chisman
Abstract
The spacing a t which trees are planted appears to be one of the more important factors influencing their early growth rate and development. Although the general nature of the effects of various spacing is fairly well understood, the magnitude of those effects is not. For example, although too wide spacing is commonly conceded to lead to an excessively tapered bole, large branches, and slow natural pruning, it is not known just how far one may go towards providing maximum growing space and still get acceptable form and quality of product in many of our commonly planted species. Bramble, Cope et al. J. For. 47: 726-732.
Competition-induced changes in developmental features of planted
Douglas-fir in British Columbia
David
G. Brand
Petawawa
National Forestry Institute,
Chalk River,
Ont., Canada KOJ 1J0
Abstract
To
provide a method of quantifying brush competition in coastal Douglas-fir (Pseudotsuga
rnenziesii (Mirb.)
Franco) plantations, data from 124 planted trees, 1-5 years old, were used to
derive a competition index for predicting changes in tree vigor measured as a
relative production rate. The index, including measures of brush proximity,
relative height, and percent ground cover, appears to act as a measure of light
interception around the tree crown. Tree vigor was found to be largely a
function of the age of the tree from planting and the competition index r2
= 0.71).
Foliage-based measures of growth vigor were more strongly related to the index
than basal area or
height measures.
The index has potential for assessing interspecific competition problems in
young Douglas-fir plantations. Brand 1986. Can. J. For. Res. 16: 191-196.
Coniferous afforestation leads to soil acidification in central Ontario
David G. Brand
Petawawa
National
Forestry Institute, Chalk River, Ont., Canada K0J 1J0
Paul
Kehoe
Ministry
of Natural Resources, Timber Sales Branch Mensuration Unit, Whitney Block,
Queen’s Park, Toronto, Ont. Canada M7A 1N3
Maureen
Connors
154
Drayton Avenue, Toronto, Ont., Canada M4C 3M2
Abstract
The
soil pH under 20 coniferous plantations on abandoned farmland at the Petawawa
National Forestry
Institute was
remeasured after 46 years and showed a significant decrease. Soils under white
spruce (Picea
glauca (Moench)
Voss) showed the greatest
degree of acidification, with the average pH in 13 plantations decreasing by
1.28. Brand, Kehoe et al. 1986. Can.
J. For. Res. 16: 1389-1391.
Standards of regeneration establishment in Canada: a case study for
Douglas-fir
David
G. Brand
Pelawawa
National Forestry Institute, Chalk River, Ontario KOJ 1JO
G.F.
Weetman
Faculty
of Forestry,
University of British Columbia, Vancouver. BC V6T 1W5
Abstract
Most stresses and hazards affecting plantation success occur during the initial establishment period. Ensuring that new stands are fully stocked with commercial species, growing acceptably, and not likely to be suppressed by brush or damaged by insects and animals, are the goals of regeneration silviculture. To focus silvicultural efforts, the concept of the free to grow plantation has evolved. This paper discusses proposed criteria for setting quantifiable, biologically based free-to-grow standards. A case study using Douglas-fir (Pseudotsuga menziesii (Mirb.) France) illustrates how free-to-grow standards could be developed. The process first requires identification of the factor or stress limiting growth. Then, free-to growth standards are based on defining a threshold level of the factor for successful tree establishment and applying a projection technique to estimate whether the trees currently below the threshold are in danger of exceeding it. Brand and Weetman 1986. For. Chron. 62: 84-90.
Brand, D.G.
Pelawawa
National Forestry Institute, Chalk River, Ontario K0J 1J0
Abstract
To provide a method of quantifying brush competition
in coastal Douglas-fir (Pseudotsuga rnenziesii (Mirb.) Franco) plantations, data from 124 planted trees, 1-5 years old,
were used to derive a competition index for predicting changes in tree vigour
measured as a relative production rate. The index, including measures of brush proximity, relative height, and
percent ground cover, appears to act as a measure of light interception around
the tree crown. Tree vigour was found to be largely a function of the age of the
tree from planting and the competition index r2=
0.71).
Foliage-based measures of growth vigour were more strongly related to the index
than basal area or
height measures.
The index has potential for assessing interspecific competition problems in
young Douglas-fir plantations. Brand 1986. Can. J. For. Res. 16: 23-29.
A competition index for predicting the vigour of planted Douglas-fir in
southwestern British Columbia
David
G. Brand
Pelawawa
National Forestry Institute, Chalk River, Ontario K0J 1JO
Gordon
F. Weetman, Paul Rehsler
University of British Columbia, Faculty of Forestry, Vancouver, BC V6T 1W5, Canada
Abstract
Formulation
for plant growth analysis, called the relative production rate, is proposed for
use in the study of perennial plants. The new measure and its yield components
are similar to current growth analysis, but use the annual increment of growth
rather than total accumulated growth, as the basis for assessing performance.
The relative production rate removes accumulated past growth of the perennating
structure, a major determinant of relative growth rate, and acts independently
of tree site as a measure of the vigour of growth. The multiplicative yield
components of this relative production rate also provide better insight into the
current morphological and physiological features of the tree than the standard
growth analysis formulations. Examples are given using Douglas-fir (Pseudoaugu
menziesii (Mirb.)
France) and red pine (Pinus
resinosa Ait.)
plantations to illustrate the methodology proposed. Brand, Weetman et al. 1986. Can.
J. For. Res. 16: 23-29.
Key
words
Pseudorsuga
menziesii (Mirb.)
France, Pinus resinosa Ait., Douglas-fir, red pine, growth, relative production rate, tree
development, competition.
Users need performance information to evaluate models
Gary J. Brand, Margaret R. Holdaway
North Central Forest Experiment Station, USDA Forest
Service, St. Paul,
Minnesota 55108
Abstract
The
important criteria for evaluating a forest growth model depend on the model’s
use. Consequently the potential use rather than the developer should determine
acceptability, particularly when the model can serve multiple purposes. To help
the user, the developer should present quantitative information about the
model’s performance under a variety of forest conditions. Brand and Hodaway
1983. J. For. 81:
235-237.
A Forestry Application of Schnute's Generalized Growth Function
Brian
V . Bredenkamp
Saasveld
Forestry Research Centre, Private Bag X6515, 6530 George, South Africa
Timothy
G. Gregoire
School
of Forestry
and Wildlife Resources, Virginia Polytechnic Institute and State University,
Blacksburg, VA
24061.
Abstract
A case is
presented where
the Chapman-Richards growth function is suitable to describe growth for a
certain period during the life
of a stand of Eucalyptus
grandis in
South Africa. Toward the end of that period, diameter growth exhibited strong
asymptotic properties. After marked competition mortality, the stand resumed
growth beyond what had appeared to be an asymptotic level and the
Chapman-Richards function could no longer be satisfactorily fitted. A generalized growth function developed by Schnute successfully tracked
this renewed growth. The parametric relationships between
the two
models are established.
Bredenkamp and Gregoire 1988. For. Sci. 34: 790-797.
Additional
keywords
Chapman-Richards
growth function, Eucalyptus
grandis. C.C.T.,
stand density effects.
An approach to density measurement in Douglas-fir
Philip
A. Briegleb
Pacific Northwest Forest and Range Experiment Station, Portland, OR
Abstract
Most American yield tables are based on natural stands that have always been dense or overdense. Most European yield tables are based on stands that were dense at establishment and were given the benefit of frequent thinnings staring at a early age. Neither of these patterns of stand history applies or is likely to apply of many years to most young stands in the Douglas-fir region. The author proposes an approach to density measurement applicable to stands having highly variable histories. The basica data are taken from intensively managed. Douglas-fir in Denmark and Russia and from both thinned and natural stands in the Douglas-fir region of western Washington, Some of the relationships found any apply in principle to other species growing in even-age stands. Briegleb 1952. J. For. 50: 529-536.
Spatial patterns of inorganic N, P availability, and organic C in
relation to soil disturbance: A chronosequence analysis
Ralph E. J. Boerner, Amy J. Scherzer,
Jennifer A. Zrinkman
Department
of Plant Biology, Ohio State University, 1735 Neil Avenue, Columbus OH 43210 USA
Abstract
This study quantified intersite variation and spatial pattern in organic C content, total
inorganic N and extractable inorganic P in soils among six sites
constituting a post-disturbance chronosequence in southwestern Ohio, USA. The
study sites included an agricultural field with a 25 + yr history of soybean
cropping (chronic disturbance), a site which had been stripped of its surface
soil and reclaimed using post-mining procedures (pseudo-stripmine, acute
disturbance), 5 and 10 year old fields, a 25-30 year old prairie restoration,
and an undisturbed, mature forest. All six sites were on soils with similar
texture and classification. With the exception of the active soybean field, P
and organic C increased with time since disturbance. Inorganic N was high in the
soybean field and mature forest and low in the other four sites, with no
consistent temporal trend. Spatial dependence of inorganic N and organic C were
high in most sites and decreased with time since disturbance. Spatial dependence
of P was lower than those of inorganic N and organic C and did not exhibit any
clear temporal trend. Each nutrient exhibited its own unique spatial and
temporal pattern of variation, and correlations among resources were weak. The
results emphasize the need for quantifying and understanding spatial patterns as
a prerequisite for developing restoration planting protocols or operationalizing
mechanistic models predicting vegetation change in specific study sites. Boerner,
Schrezer et al. 1998. Appl.
Soil Ecol. 7: 159-177. 1998
Author
Keywords
nitrogen, phosphorus, organic carbon, reclamation, semivariance analysis,
spatial pattern, succession
KeyWords
Plus
forest, geostatistics, mycorrhizal, variability, ecology, plants, long
H
Brix
Environment Canada, Canadian Forestry Service, Pacific Forest Research Centre, 506 West Brunside Road, Victoria, BC, Canada V8Z 1M5
Abstract
The effects of nitrogen fertilization on foliage nitrogen concentration, rates of photosynthesis, and stem diameter growth were studied for Douglas-fir (Pseudotsuga Mensiesii (Mirb.) Franco) trees, with a range of fertilizer applications from 0 to 896 kg N/ha. Ammonium nitrate (AN) and urea were compared as nitrogen sources. AN provided for a higher foliage nitrogen concentration and better growth the 1st year, but there was no source effect thereafter. A significant relationship was obtained between foliage nitrogen concentration and rate of photosynthesis, with an optimum rate at 1.74% foliar nitrogen and with no effect of nitrogen source. Stem diameter growth was increased at all fertilization rate, although no effect of the two lowest rates of fertilization (112 and 224 kg N/ha) was found on foliar nitrogen concentration. Brix 1981. Can. J. For. Res. 11: 775-780. 1981.
Analysis of economic impacts on thinning and rotation for Douglas-fir,
using dynamic programming
J.
Douglas Brodie, Darius M. Adams, Chioang Kao
Department of Forest Management, School of Forestry, Oregon State University, Corvaliis or 97331
Abstract
Impacts of regeneration cost, initial stocking level, site, quality premiums, and variable logging costs on thinning and rotation are derived with a forward-recursion dynamic programming algorithm. The relative efficiency and information provided in intermediate solutions is compared to previously used backward recursions. A resolution if offered of an earlier controversy regarding the form of dynamic programming algorithm and validity of results in studies of thinning and rotation. Brodie, Adams et al. 1978. For. Sci. 24: 513-522. 1978.
Additional
key words
Optimization, regeneration cost analysis, quality premium, economic cost of reduced stocking
J. Douglas Brodie, Chiang Kao
Department of Forest Management, School of Forestry, Oregon State University, Corvallis or 97331
Abstract
Accelerated
diameter growth as a result of thinning must be incorporated into dynamic
programming analysis to account for reduced logging cost and increased income as
the size of harvested material increases. A three state-descriptor model is
necessary to do this, but a three-descriptor formulation encounters problems of
rounding, storage, and computational efficiency.
Techniques for overcoming these problems are outlined and applied in
representative demonstrations of the model. Brodie and Kao 1979. For. Sci. 25: 665-672. 1979.
Additional key words
Pseudofsrosa
menziesii, logging cost premium, quality premium, economics.
rotation.
A geostatistical study of soil data from an irrigated vineyard near
waikerie, south Australia
Brooker PI,
Winchester JP
Department of Geology and Geophysics, University of Adelaide, Adelaide,
South Australia 5005
S.A. Department of Primary Industries, Loxto Research Center, Loxton, South Australia 5333
Abstract
Effective supply of water for irrigation requires that the capacity of the soil
to hold water be measured. Field measurement of the depth and texture of each
soil layer in a profile allows calculation of the readily available water for
the site. The spatial variation of readily available water is characterized by
its semivariogram, calculated over the property under study, This function is
used in a geostatistical analysis to determine the average value of the variable
over areas watered by opening irrigation valves. The accuracy of such estimates
is also provided in the geostatistical procedure of kriging. A case study
applied to an existing vineyard near Waikerie in South Australia deals with root
zone readily available water and depth of topsoil, The property has been sampled
with a grid 75 m x 75 m. Irrigation valve areas are typically 1.3 ha. A 50%
reduction in confidence intervals for the estimates occurs when the valve areas
are estimated by kriging compared with those obtained using a simple average of
the samples contained within the area. Of interest is the anisotropy seen in the
semivariograms. Variation in the N-S direction is much more rapid than in the
E-W. This factor is currently incorporated into the rectangular design of the
irrigation valve areas. It is suggested that it should also influence sampling
design. Brooker, Winchester et al.
1995. Environ. Int. 21: 699-704.
Timber products output and timber harvests in Alaska: projections for
1997-2010
David
J. Brooks
Forestry
Sciences Laboratory, 3200 S.W. Jefferson Way, Corvallis, OR 97331
Richard
W. Haynes
Forestry
Sciences Laboratory, P.O. Box 3890, Portland, OR 97208.
Projections of Alaska timber products output, the
derived demand for raw material, and timber harvest by owner are developed from
a trend-based analysis. These projections are revisions of projections made in
1990 and again in 1994, and reflect the consequences of recent changes in the
Alaska forest sector and long-term trends in markets for Alaska products. With
the closure of the two southeast Alaska pulp mills, demand for Alaska National
Forest timber now depends on markets for sawn wood and the ability to export
manufacturing residues and lower grade logs. Three alternative projections are
used to display a range of possible future demand. Areas of uncertainty include
the prospect of continuing changes in markets and in conditions faced by
competitors and the speed and magnitude in investment in manufacturing in
Alaska. The sensitivity of model output to changes in key assumptions is
displayed.
Keywords
National Forest (Alaska), forest sector models, lumber
Spatial structure of light and dipterocarp seedling growth in a tropical secondary forest
Bebber D, Brown N, Speight M, Moura-Costa P, Wai YS
Abstract
Variation in forest canopy openness influences the growth and survival of
seedlings below, and is therefore of practical importance when wishing to
restock a forest with valuable timber species after logging. In this study,
growth and light environment of dipterocarp seedlings in an enrichment planting
project in secondary lowland forest in Borneo were analyzed using geostatistics,
in order to determine the spatial relationships between canopy openness and
seedling performance, Seedling growth was correlated with canopy openness
measures up to 50 m away along planting lines but was uncorrelated across
planting lines, because the dense understorey between planting lines blocked
lateral light. It is recommended that planting be conducted in patches rather
than along lines, so that understorey clearance can allow light from canopy gaps
in all directions to reach seedlings. Bebber, Brown et al. 2002. For. Ecol. Manage. 157:
65-75.
Author
Keywords
geostatistics, enrichment planting, dipterocarpaceae, seedling growth, spatial
autocorrelation, canopy openness
KeyWords
Plus
lowland rain-forest, solar-radiation, canopies, gap, autocorrelation, understory,
sabah, danum
A system design for tracking the carbon flux from changes in cover, use
,and management of the land
Sandra
Brown
US
Environmental
Protection Agency Environmental Research Laboratory 200 SW 35th St. Corvallis, OR 97333, USA
Lowell
F. Smith
Office
of Research and Development, US Environmental
Protection Agency Washington, DC 20460
Abstract
The development of a global, terrestrial C-flux
tracking system is motivated by the need of scientists to balance the
terrestrial C budget, including estimating the magnitude, precision, and
location of C sources and sinks, and how they change over time; and by the
needs of policy makers for a sound scientific basis to deal effectively with the
socioecono9mic implications of climate change and for negotiations under the UN
Framework Convention on Climate Change (UNFCCC).
To meet these needs, we propose that a C-flux tracking system should be
capable of : measuring changes in cove, us, and management of the land
(LC/LU/LM) within nations; accounting for net C gains and losses in ecosystems brought
about by past and resent changes in LC/LU/LM, natural disturbance,
climate, and atmospheric composition; estimating errors and range in variation of
the C flux; scaling up consistently to regions and the globe; auditing for
compliance with national and international obligations under the UNFCCC; and
tracking the net consequences of policy actions that change the magnitude and
direction of C sinks and sources. In this paper, we present a research and
development program for producing and testing a system to track the C flux
caused by changes in LC/LU/LM only, including a discussion of the key data
requirements and their availability, and a series of parallel and sequential
tasks to produce C flux estimates and their errors for major countries, test
methodology, assess applicability of available data, establish programs to fill crucial
data gaps, calibrate and validate remote sensing products, and establish
national and international cooperation, We conclude with a discussion as to how
such a tracking system could be implemented
Use
of Profile Equations in Tree Volume Estimation
David
Bruce, Timothy A. Max
Pacific
Northwest Research Station, USDA, Forest Service P.O. Box 3890, Portland, Oregon 97208-3890
Abstract
Profile equations are used today for tree volume
estimation because they are more flexible in estimating partial stem volumes and
are just as accurate for total volume as two other systems.
Profile
models have been used for more than 200 years,
but recent developments abetted by
electronic computers make them more versatile today. Methods of accounting for variation in form, determining accurate actual volumes, and assuring desirable characteristics of models are described. Stem profile models currently used are discussed as well as anticipated improvements. Bruce and Max 1989. USDA, For. Ser., Pac. Nw. Res. Sta. (Syracuse, Aug 89). 1-8. 1989.
Development of empirical forest growth models
David
Bruce
Pacific
Northwest Research Station, USDA, Forest Service P.O. Box 3890, Portland, Oregon 97208-3890
Abstract
Empirical
models predicting periodic growth of trees and forests are based on measurements
in the forest at two or
more times and are developed without direct reference to the biological
processes involved. Process models describing changes in trees and forests may
be more complicated than empirical models; although they emphasize processes,
those that predict quantities necessarily include some empirical elements.
Growth models programmed to run on
computers can be listed in order
of increasing complexity, both forming progressions of information content and
change best uses for
the models. A
recent growth simulator that adds measures of the effects of nutrient cycling to
an empirical model shows promise of increasing versatility without improving
reliability of growth estimates under conditions currently measurable. Growth
models differ greatly in how they handle competition among trees, and it has been
found that competition measures at the stand level often work as well as those
at the tree level. Models are evaluated objectively by predicting and observing growth
in stands
that sample the conditions modeled. Simple empirical models are accurate enough to
guide short-term
forest management decisions, because prudent managers monitor growth of their
stands. Mixed models including both empirical and process elements are likely to
be needed to make reliable long-term forecasts and credible growth predictions
for large heterogeneous areas or for management conditions that cannot currently
be observed.
Yield differences between research plots and managed forests
David
Bruce
Pacific Northwest Forest and Range Experiment Station, Portland, Oregon 97232
Abstract
Differences between timber yields on small research plots and on managed forests are due mainly to differences in definition of forested area, in scale and quality control of management treatments, and in uniformity of the stands. In large areas where management has not yet made stands uniform, research results may serve only as general guides to potential growth. The manager who is practicing some degree of intensive forestry can often find research data on which to based accurate estimates of growth and yield. To apply the information, he must exclude unproductive areas from estimates of his acreage, monitor stands for damage, and supervise treatments efficiently. There is however, no single magic number that adjust for differences in growth between research plots and larger managed forests. Bruce 1977. J. For. 75: 14-17. 1977.
Development of a system of taper and volume tables for red alder
David Bruce, Robet O. Curtis, Caryanne Yancoevering
Pacific Northwest Forest
and Range Expt Sta., Forest Service, US. Dept. of Agric., Portland, Oreg.
Abstract
An estimating equation was derived for red alder ( Alnum rubra Bong.), expressing ratio of squared upper stem d.i.b to squared dbh outside bark as a function of dbh, total height, and the 3/2, 3rd, 32nd, and 40th powers of relative height. This equation formed the basis for a system of tables and equations which provides estimates of tree volume for various combinations of product units, utilization limits, and size classes of material. The methods used should also be applicable to other species. Bruce, Curtis et al. 1968. For. Sci. 14: 339-350. 1968.
A. Bruckner
University
of Agricultural Sciences, Institute of Zoology, Gregor-Mendel-Str. 33, A-1180
Vienna, Austria
E.
Kandeler
University
of Hohenheim, Institute of Soil Science, Department of Soil Biology, Emil-Wolff-Str.
27, D-70599 Stuttgart, Germany
C.
Kampichler
Free
University of Berlin, Institute of Zoology, Grunewaldstr. 34, D-12165 Berlin,
Germany
Abstract
Samples of two perpendicular transects from an even-aged Norway spruce ( Picea
abies) forest were used for geostatistical analysis of forest floor water
content (WC), pH, substrate-induced respiration (SIR, a measure of microbial
biomass), and N mineralization (Nmin). Nmin data did not fulfill the stationary assumptions of geostatistics and had to be detrended prior to analysis. All
variables exhibited spatial structure. The degree of spatial dependence was
generally high (60%-95%). pH and SIR were isotropically distributed; WC and Nmin
were anisotropic. Three different scales of spatial variability were detected at
the site. (1) A fine-scale pattern with ranges < 1 m that was attributed to
retarded decomposition, poor chemical and structural diversity of P. abies
litter, and lacking bioturbatic activity of earthworms. (2) A mesoscale pattern
was indicated by sinoidal periodicity of most variograms, with inflection points
every 1.0-1.5 m. This periodicity probably reflected the influence of regularly
spaced tree individuals. (3) Nmin and WC exhibited unexplained long-range trends
that exceeded transect length. Bruckner, Kandeler et al. 1999. Geoderma. 93: 207-223. 1999.
Author
Keywords
spatial distribution, geostatistics, variograms, autocorrelation, decomposition
KeyWords
Plus
southwestern british-columbia, individual tree canopies, in-field mesocosms,
microbial biomass, spruce forest, faunal complexity, heterogeneity, litter,
canada, nitrification
A Markov chain approach to the prediction of diameter distributions in
uneven-aged forest stands
Harold
D. Bruner
Weyerhaeuser
Company. Mounruin Pine, Arkansas
71956
John
W. Moser,
Jr.
Department
of Forestry and Conservation. Purdue University, Wess Lafoyefte. Indiana
47907
Abstract
A simple stochastic model to predict future diameter distributions, number of survivor trees, number of mortality trees, and number of harvested trees is developed from conventional continuous forest inventory data over two measurement periods. The length of the prediction period is limited to multiples of the remeasurement period. Data used to construct the model and test its predictive ability came from 19 consecutive years of C.F.I. measurements collected in Washington County, Wisconsin. Results indicate that number of survivor trees can be predicted with very good accuracy; predictions of diameter distributions, number of mortality trees, and number of harvested trees are less accurate. Bruner and Moser, Jr. 1973. Can. J. For. Res. 3: 409-417.
Sensitivity of texture of high resolution images of forest to
biophysical and acquisition parameters
Bruniquel-Pinel V, Gastellu-Etchegorry JP
Centre
d’Etudes Spatial, CNES-CNRS-UPS, Bpi 2801, 31401 Toulouse Cedex 4, France.
Abstract
This article presents a quantative analysis of the sensitivity of textural
information of high resolution remote sensing images of a forest plantation (Les
Landes, France) to a number of biophysical parameters: crown diameter, distance
between trees and rows, tree positioning, leaf area index (LAI), and tree
height. Influence of acquisition parameters (spatial resolution, spectral domain
and viewing, and illumination configurations) is also investigated. The work is
realized with the discrete anisotropic radioactive transfer model (DART) simulated
images with which we quantify texture with variograms. Results point out the
complex dependency of variogram characteristics (range, sill, amplitude of
oscillations) on biophysical and acquisition parameters. Neglect of spatial
variations of the reflectance of canopy elements, as in most geometric-optical
models, can lead to important errors. This stresses the interest of accurate
radiative transfer models, such as DART. Although tree crown diameter is the
most influential biophysic parameter, its influence may be totally masked by
acquisition parameters. Finally, theoretical results were tested against high
resolution airborne data (1.67 m resolution). Although encouraging results were
obtained, this work both confirms the difficulty of extracting reliable texture
information from real remote sensing data, and stresses the usefulness of
radiative transfer models for studying the texture of high resolution satellite
images.Bruniquel-Pinel and Gastellu-Etchegorry 1998. Remote Sens. Environ. 65: 61-85. 1998.
KeyWords
Plus
variograms
A
light model for spatially explicit forest stand models
Andreas Brunner
Universitat
Freiburg, Waldbau-Institut, Tennenbacher Str. 4, D 79085 Freiburg, Germany
Abstract
There is an increasing demand for detailed simulation of light in forest stand
models. This is particularly true for spatially explicit growth models that
represent individual trees. A large number of light models has been developed
for forest stands, but only a few are spatially explicit and none has become
part of a forest growth model for management applications. This paper describes
a light model called tRAYci that can be used with models including a
three-dimensional canopy representation calculated from crown shapes. The
unobstructed irradiation of PAR above the canopy is simulated by combining
submodels for the spatial distribution of direct and diffuse light. For a given
paint within a forest stand, up to 32,400 sample rays are traced in the upper
hemisphere, and for each sample ray, its path length in the simulated canopy
space is calculated. PAR attenuation in the modelled crown space is simulated
according to Bouguer's law using leaf area density for each species as the only
variable. The results are given as percentage of the above canopy Light (PACL)
for a defined growth period no shorter than a few weeks. PACL can be calculated
for every point in a simulated stand. Light maps, profiles, and average PACL
over the crown surface for individual tree crowns can be generated. The model
was validated using light measurements and estimates from hemispherical
photographs from a Douglas-fir stand in British Columbia. Sensitivity analyses
for all model variables are presented and demonstrate the importance of crown
representations for light models. Brunner 1998. For. Ecol. Manage. 107: 19-46. 1998.
Author
Keywords
light, model, PAR, crown, forest
Keywords
Plus
intercepted solar-radiation, diffuse sky radiance, even-aged stands, leaf-area
index, abies l karst, Douglas-fir, canopy structure, hemispherical photography,
deciduous forest, individual tree
D.J. Brus
DLO
Winand Staring Centre for Integrated Land, Soil and Water Research, P.O. Box
125, 6700
AC
Wageningen, Netherlands
L.E.E.M.
Spatjens
Laboratory
for Soil and Crop Testing, P.O. Box 115, 6860 AC Oosterbeek, Netherlands
J.J.
de Gruijter
DLO
Winand Staring Centre for Integrated Land, Soil and Water Research, P.O. Box
125, 6700
AC
Wageningen, Netherlands
Abstract
A soil sampling scheme for estimating the mean extractable P concentration of
fields is designed to be used as a tool for environmental regulation of the
application rates of manure. The field to be sampled, is split up into
geographically compact blocks of equal area that are used as strata. From each
stratum one sampling point is selected by Simple Random Sampling. These samples
are bulked into one composite for the field. The geographical stratification is
performed by restricted least-squares clustering of raster cells using the
coordinates of the midpoints as classification variables and the within-group
sum of squares as the minimization criterion. Using a variance model and a cost
model, the numbers of sample points and laboratory analyses are optimized simultaneously, given a maximum allowed variance of the total error (sampling
error plus measurement error). To predict the sampling variance, variograms have
been estimated for 16 fields differing in land-use, soil parent material and
phosphate level. A pooled relative variogram was used to predict the sampling
variance for various sample sizes (5 to 50), field-areas (1 to 10 ha) and
phosphate levels (for grassland 20 to 80 mg P2O5 extracted in ammonimum lactate
per 100 g soil, for arable land 20 to 80 mg P2O5 extracted in water per 1 dm(3)
soil). The cost model consists of three components: (i) fieldwork cost; (ii)
field equipment cost and, (iii) laboratory cost. For the 16 fields, the
predicted sampling variance of the Stratified Sampling design is 0.8 to 0.4
times the predicted variance of Simple Random Sampling if 40 points were
sampled. To estimate the mean extractable P concentration with a total variance
less than or equal to 9, replicate measurement of the composite only pays if the
mean extractable P concentration of the field exceeds 40 to 50. This critical
phosphate level increases with the maximum allowed variance of the total error.
Brus, Spatjens
Author
Keywords
soil testing, Stratified Random Sampling, geostatistics, cluster analysis, optimization, composite samples
Keywords
Plus
soil
Survival predictions for major Lake States tree species
North
Central Forest Experiment Station, Forest Service--U.S. Department of
Agriculture, 1992 Folwell Avenue, St. Paul, Minnesota 55108
Abstract
A
model of species' coefficients are reported for predicting individual tree
survival for 10 Lake States species. Tree attributes are diameter growth rate
and diameter at breast height. Regional and local performances are summarized.
Buchman 1983.USDA For. Serv. Res. Pap. NC-233. 8p. 1983
Key
Words
mortality rates, mortality models, survival model, mortality coefficients, tree risk
Guide to evaluating forest growth projection systems
Roland
G. Buchman, Stephen R. Shifley
North Central Forest Experiment Station, Forest Service--U.S.
Department of Agriculture, 1992 Folwell Avenue, St. Paul, Minnesota 55108
Abstract
The number and complexity of forest growth projection systems may make the task of evaluating and comparing alternative systems seem overwhelming. Evaluations typically require the synthesis of many quantitative and qualitative factors. Managers can often benefit by separately considering the application environment, the performance, and the design of each candidate system. Although selection of evaluation criteria depends largely upon the application of being considered, guidance is available form the many evaluation criteria in the literature. Buchman and Shifley 1983. J. For. 81: 232-234
Plant self-thinning and leaf area dynamics in experimental and natural
monocultures
Michael
1. Hutchings, Christopher S. J. Budd
School
of Biological Sciences, Univ. of Sussex, Falmer, Brighton, Sussex BNI 9QG,
England.
Abstract
The
gradient of the relationship between mean plant weight and density for many
species in self-thinning monocultures is known to be -3/2. There is evidence in
the literature that this gradient may decline as light intensity falls. A recent
controversy has centred upon whether or not the -3/2 gradient can be restored at
low light intensities by graphing mean leaf area per plant against density. An
experiment was conducted, using Trifolium pratense L.
grown at three light intensities, to establish the gradient of this
relationship. Whereas the mean weight vs. density gradient remained near -3/2 at
all light intensities, the mean leaf area vs. density gradient approximated to
-1.0, indicating that leaf area index stays constant as thinning proceeds. Thus,
the results do not support the proposal that alterations in leaf area ratio act
to restore the -3/2 gradient to the mean leaf area vs. density graph at low
light intensities. Support for these findings is discussed, including data from
field monocultures of Mercurialis
perennis L.
Hutchings and Budd 1980. Oikos. 36: 319-325.
Spatial
sampling design based on stochastic complexity
M. C. Bueso,
J. M. Angulo
Departamento
de Estadistica e Investigacion
Operativa, Universidad de Granada
Campus
de Fuente Nueva, s/n, E-18071 Granada, Spain
G.
Qian
School
of Statistical Science, La Trobe University, Bundoora, Victoria, VIC 3083,
Australia
F.
J. Alonso
Departamento
de Estadistica e Investigacio n Operativa, Universidad de Granada, Campus de
Fuente Nueva, s/n, E-18071 Granada, Spain
Abstract
A new methodology is introduced for spatial sampling design when the variable of
interest cannot be directly observed, but information on it can be obtained by
sampling a related variable, and estimation of the underlying model is required.
An approach based on entropy has been proposed by Bueso. Angulo, and Alonso
(1198, Environ. Ecol. Statist. 5. No. 1, 29-44) in the case where a model for
the involved variables is given. However. in some cases a predetermined
structure modelling the behaviour of the variables cannot be assumed. In this
context, we derive criteria by solving the design problem based on the
stochastic complexity theory and on the philosophy of the EM algorithm. For
applying the proposed criteria a computational procedure is developed based on
the supplemented EM algorithms. The methodology is illustrated with a numerical
example. Bueso, Angulo et al. 1999. J. Multivariate Anal. 71:
94-110.
Author
Keywords
EM algorithms, incomplete data, minimum description length, network design,
stochastic complexity
KeyWords
Plus
network design, lattice processes, incomplete data, entropy, EM, algorithm,
variance
Using biomass to improve site quality and carbon sequestration
Marilyn
A. Buford, Bryce J. Stokes
USDA
Forest Service, Vegetation Management and Protection Research P.O. Box 96090, Washington, DC 20090-6090,USA
Felipe
G. Sanche
USDA
Forest Service, Southern Research Station,
P. O. Box 12254, Research Triangle Park, NC 27709, USA
Emily
A. Carter
USDA
Forest Service, Southern Research Station, 520 Devall Drive, Auburn University,
AL 36849-5418,USA
The future demands on forest lands are a concern because of reduced productivity, especially on inherently poor sites, sites with long-depleted soils, or those soils that bear repeated, intensive short rotations. Forests are also an important carbon sink and, when well managed, can make even more significant contributions to sequestration and to reduction of greenhouse gases. This paper looks at the use of forest biomass as a carbon sink and as a source of nutrients for enhancing or restoring site productivity. It is hypothesized that wood incorporated into the soil will store carbon for an unknown length of time, and an example analysis using logging residues is presented. A field study was also conducted to evaluate the use of mulching and tilling as site preparation tools for incorporating biomass into the soil. Buford, Sanche et al. P.7. SESSION 4:carbon balances and sequestration in conventional Systems.
Key Words
carbon, nutrients, site preparation, biomass
Probability distribution as models for mortality
M.A. Buford
Champion International Postdoctoral Fellow, School of Forestry and
Wildlife Resources, Virginia Poly technic Institue and State University, Blacksburg, VA 24061
W. L. Hafley
School of Forest Resources, North
Carolina State University, Box 8002,
Raleigh, NC 27695-8002
Abstract
The necessary attributes for a mortality model for an even-aged forest stand are started. The Weibull distribution, the Gamma distribution, and the negative binominal distribution are proposed based on their previous use in failure research and as mortality models. A distribution derived from the Richards generalization of the Von Bertalanffy growth equation is proposed. The four functions are examined mathematically and empirically using data from a loblolly pine spacing study to determine their usefulness as mortality models. The negative binomial distribution and its continuous analog, the gamma distribution show instability under right-censoring and are computationally difficult. The Weibull distribution show extreme instability under right-censoring due to constrains on the location of the inflection points of its probability density function, limiting its value as a mortality model. The distribution derived from the Richards generalization of the Von Bertalanffy function is table under slight-censoring shows no constraints on assumable shapes, and is computationally simple. Buford and Hafley 1985. For. Sci. 31: 331-341.
Construction of forest growth models based on physiological principles
T.E.
Burk
Department of Forest Resources, College of Natural Resources, University of Minnesota, 1530, North Cleveland Avenue , St. Paul, MN, 55180
R.
Sievanen
Department of Mathematics, The Finnish Forest Research Institute, Unioninkatu 40 A,00170 Helsinki, Finland
A.
R. EK
Department of Forest Resources, College of Natural Resources, University of Minnesota, 1530, North Cleveland Avenue , St. Paul, MN, 55180
Abstract
Basic structures for management-oriented forest growth models have changed little over last several decades. If additional progress is be made in the prediction of forest growth, especially under a potentially changing environment, new modeling approaches must be sought. We discuss the use of physiological principles for construction of forest growth models. An example of such a model is presented for aspen. Extensions necessary for modeling at the tree level are discussed. Key components and methodological advances requisite to making such models practical for forest management decision making are outlined. Burk, Sievanen et al. 1989. P.1-10. Aspen Symposium. 1989.
A simple algorithm for moment-based recovery of Weibull distribution
parameters
Thomas E. Burk, James D. Newberry
Department of Forestry, Virginia Polytechnic Institute and State
University, Blacksburg, VA 24061
Abstract
A
solution technique to solve for the parameters of a three-parameter Weibull
distribution is presented. The specific application of interest concerns the use
of the Weibull in yield model. Two alternative formulations are discussed, and a
numerical example is presented. FORTRAN
programs which implement the formulations are available from the authors.
Burk and Newberry 1984. For. Sci. 30: 329-332. 1984.
Additional
key words
Growth
and yield modeling, diameter distribution
Marianne K.
Burke
USDA Forest Service, Center for Forested wetlands
Research, Chleston, SC 29414, USA
B.
Graeme Lockaby
School of Forestry, Auburn University, Auburn,
AL36849, USA
William
H. Conner
Belle
W. Baruch Forest Science Institute, Clemson University, Georgetown, SC 29442 USA
Abstract
Relative to effects of flooding, little is known about the influence of
hydrology-nutrient interactions on aboveground net primary production (NPP) in
forested wetlands. We found that nutrient circulation and NPP were closely
related along a complex physical, chemical, and hydrologic gradient in a
bottomland hardwood forest with four distinct communities. Aboveground biomass,
NPP, biomass partitioning to stem production, growth efficiency, and soil
macronutrient availability were greatest in the flooded zone, possibly because
of the stable hydrologic regime. In the wet transition zone, trees were least
productive, nutrient use efficiency was highest, and N retranslocation from
foliage before abscission was "complete." Wet and dry transition zones
had the lowest litterfall quality. Soil organic matter was negatively correlated
with extractable NH4-N plus NO3-N before in site incubations and positively
correlated with litterfall lignin/N ratios. Lignin/P and C/N ratios were
positively correlated with exchangeable soil Ca and Mg, cation exchange
capacity, and clay content and negatively correlated with extractable soil P. We
concluded that periodic flooding and associated widely fluctuating soil
chemistry resulted in disequilibria between the plant community and
environmental conditions, which led to nutrient deficiency and low NPP in the
transition zones compared with the continuously flooded and mesic zones. Burke,
Lockaby et al. 1999. Can. J. For. Res. 29: 1402-1418. 1999.
KeyWords
Plus
southeastern floodplain forests, use efficiency, nitrogen mineralization,
loblolly-pine, photosynthetic rates, growth-responses, nyssa-sylvatica,
swamp-forest, wetlands, resorption
Stand modeling for radiata pine in New Zealand
Harold
E. Burkhart
Department
of Forestry,
Virginia Polytechnic Institute and State University. Blacksburg. VA, U.S.A.
24061
Abstract
Intensive
forest management
requires reliable information on stand dynamics, growth, and yield. A
variety of modeling
options will
probably be
required to provide information on which to base the full spectrum of forest
management decisions. In
this paper, modeling
alternatives are regarded as part of a
continuum of complementary
systems rather than as mutually exclusive options. A brief overview of selected
stand modeling alternatives is given, with some discussion of general situations for which the
various approaches might prove efficient; and data bases for stand modeling are
considered. Suggestions are offered for modeling Pinus
radiata stands
in New Zealand.
Burkhart 1977. N. Z. J. For.
22: 297-307. 1977.
Site index equations for Douglas fir in Kaingaroa forest
H.E. Burkhart, R.B. Tennent
Forest
Research Institute, New Zealand Forest Service, Rotorua
Abstract
Site
index (height of the dominant stand at some specified reference age) is a practical and commonly used method for quantifying site
quality in pure even-aged stands. Permanent plot records form Douglas fir (Pseudotsuga
menziesii (Mirb) Franco) stands in Kaingaroa Forest were used to compute
site index equations. Coefficient for the equation developed are presented, and
limitations in the application of the equation are discussed. Burkhart and
Tennent 1977. N. Z. J. For.
Sci. 7: 417-419. 1977.
Comparisons
of Modeled Height Predictions to Ocular
W.A.
Bechtold, S.J. Zarnoch, and W.G. Burkman
USDA
Forest Service, Southern Research Station,
Asheville, NC.
Abstract
Equations used by USDA Forest Service Forest
Inventory and Analysis projects to predict individual tree heights on the basis
of species and dbh were improved by the addition of mean overstory height.
However, ocular estimates of total height by field crews were more accurate than
the statistically improved models, especially for hardwood species. Height predictions from the improved equations
attained the desired measurement quality objective only 57% of the time, while
ocular estimates achieved the desired accuracy 75% the time. Bechtold, Zarnoch
et al. 1998. South. J. Appl.
For. 22(4):216-221. 1998.
The occurrence and possible sources of nitrite in a grazed, fertilized,
grassland soil
Burns LC,
Stevens RJ, Smith RV
Department
of Agricultural and Environmental Science, the Queen’s University of Belfaast,
NewForge Lane, Belfast BT9 5PX Northern Ireland, UK
Cooper JE
Department
of Applied Plant Science,the Queen’s University of Belfaast, NewForge Lane,
Belfast BT9 5PX Northern Ireland, UK
SOIL BIOLOGY & BIOCHEMISTRY
27 (1): 47-59 JAN 1995
Abstract
Concentrations of NO2--N in land drainage and river waters in Northern Ireland
in recent years have frequently exceeded EEC guide values. Very little
information exists to indicate if and when NO2- accumulates in soil solution,
and whether NO2- from the soil profile is the source of NO2- in drainage and
river waters. The occurrence of NO2- in the field was studied and laboratory
incubation experiments carried out to determine the possible sources of NO2- in
grassland soil. Field studies were carried out to determine the occurrence and
spatial variability of NO2- in a grazed, grassland soil. Plots receiving either
100 or 500 kg N ha-1 yr-1 were systematically sampled in May and October 1992.
Concentrations of NO2- in soil were highly variable and ranged from 0 to 2.747
mug N g-1, the data being significantly skewed to the right. Correlation
matrices and stepwise multiple regression analyses showed relationships between
NO2- and a number of soil variables. Nitrite appeared to be related to variables
which indicated its occurrence as a result of nitrification of either
fertilizer- or urine-derived NH4+. Nitrate was repeatedly correlated to NO2-
concentrations, suggesting that both nitrification and nitrate reduction may be
responsible for NO2- formation. Spatially, nitrite occurred at random, basic geostatistic
producing only one variogram, showing an increase in NO2-
concentrations with an increase in distance between sampling points. There was
no pattern to the distribution of NO2- with depth, indicating differences in the
ratios of the rates of NO2- production and consumption. Numbers of NH3-oxidizers
were consistently higher than numbers of NO2- -oxidizers, with some degree of
variation between samples. The microbial aspects of NO2- formation are
discussed, including partial recycling of NO2- via the NO3- pool, and possible
causes of NO2- accumulation due to the inhibition of NO2--oxidizing bacteria.
Laboratory incubation studies were carried out in which measurable NO2- flushes
were induced. Increasing soil pH and NH4+ concentrations produced large NO2-
flushes, which peaked after about 17 days of incubation, then rapidly declined.
Soil incubated with urea produced NO2--N concentrations equivalent to those
encountered in the field, suggesting that NH4+ oxidation accounts for a
significant proportion of NO2- formed in this soil. Burns,
Stevens et al. 1994. Soil Biol. Biochem. 27: 47-59. 1994.
Keywords
Plus
banding nitrogen fertilizers, nitrosomonas-europaea, nitrate reduction, temporal
patterns, denitrification, nitrification, nitrobacter, growth, nitrifiers,
bacteria
Spatial variability of topsoil characteristics within one silty soil
type - Effects on clay migration
Bartoli F, Burtin G
Cnrs,Ctr
Rech Petrog & Geochim,F-54501 Vandoeuvre Nancy,France
Univ Nancy 1,Cnrs, Upr 6831,Ctr Pedol Biol,Bp 5,F-54501 Vandoeuvre Nancy,France
Leviandier
T, Gafrej R
Cemagref,Div
Hydrol,F-92164 Antony,France
GEODERMA
68 (4): 279-300 NOV 1995
Abstract
In order to understand and to model soil runoff erosion as well as to optimize
sampling schemes, improved understanding of spatial variability of clay and some
other soil erosion parameters is needed. For this purpose, two complementary
approaches to the study of spatial variability of silty topsoil characteristics,
the pedological approach and the fractal approach applied to geostatistics, were
carried out in the context of soil erosion within the intensive cereal
agriculture zone of northwestern Europe.
Fractal
geometry provides one synthetic key to the description of classical
geostatistical tools such as variograms. Spatial structures of soil properties
of each of the three topsoil pedological units were mostly characterized along
the slope by the ranges of the fractal one-dimensional space domains and their
scale invariants: the fractal dimensions. Results suggest that, within each
topsoil pedological unit, these scale invariants are relevant qualifiers of the
intrinsic topsoil variability, which can be modelled as a fractal Brownian
process and should be incorporated in simple recursive or complex network soil
erosion models. Different surface fractal dimensions, in a one-dimensional
space, have been found within these three topsoil units for each soil parameter
studied (multifractals), All the data have been aggregated within the whole
one-dimensional slope transect in order to obtain both possible general scale
laws on clays and other soil characteristics and possible evidence concerning
underlying soil erosion mechanisms by particle runoff. B artoli, Burtin et al.
1995.
KeyWords
Plus
fractal dimensions, aggregate stability, multiscale sources, water properties,
erosion, runoff, fragmentation, infiltration, porosity, networks
Burton, J.D.
Alexandria
Forestry Center, Southern Forest Experiment Station, Forest Service-USDA,
Pineville, Louisiana.
Second-growth even-aged loblolly-shortleaf pine stands on good and medium sites were thinned from above or below to a basal area of 70 ft2, 85 ft2, and 100 ft2/acre, to an increasing basal area, or according to the judgment of a committee. Treatments began at age 20 for original plots and at age 25 for supplementary plots (on good sites only), which were thinned to a basal area of 55ft2, 115 ft2, or 130 ft2/acre. Stands were thinned every 5 years. At age 45, most trees in good-site original plots and supplementary plots thinned from below were in the l0-inch d.b.h. class and larger. In the 70-ft2, 85-ftk,and "increasing" treatments, most stems were in the 15-inchclass and larger. On good-site original plots thinned from below, at 45 years standing sawtimber volume for trees (>=)9.6 inches d.b.h. containing (>,=) one 16-ft log to an 8-inchtop was greatest in "increasing" treatment plots and least in 85-ft2and 100-ft2/acre plots. In supplementary plots, standing board-foot volume was greatest in 130-ft2 and least in 55-ft2/acre plots. On medium sites, standing volume was greatest in "judgment" and l00ft and least in 70 ft2/acre plots. Sawtimber m.a.i. was still increasing rapidly at age 45 in all treatments. Cubic-foot m.a.i. was increasing slowly on medium sites but declining in supplementary plots and in all good-site original plots except the 70-ft" and "increasing" treatments. On good sites, p.a.g. in board feet culminated between ages 30 and 35 in the 70-ft2/ and 85.ft2 treatments and between ages 40 and 45 in "increasing" plots. On medium sites, p.a.g. apparently was still increasing at 45 years. On both sites, sawtimber ingrowth was much less complete at age 45 in thin-from-above stands than in those thinned from below. On good sites, sawtimber yield to age 45 in plots thinned from below was greatest in "increasing" treatment plots and least in l00- ft2/acre stands. In supplementary plots, sawtimber yield was greatest in 55-ft2 and least in 115-ft2/acre treatments. On medium sites, sawtimber yield was greatest in "judgment" and l00ft and least in 70-ft2/acre stands. On good sites, cubic-foot yield to age 45, in peeled stemwood to a 3-inch d.i.b., trees (>,=) 3.6 inches d.b.h., in plots thinned from elow,was greatest for "increasing" treatment plots and least for 70-ft2 stands. In supplementary plots, cubic-foot yield was greatest for 130-ft2 and least for 55-ft2 /acre plots. On medium sites, cubic-foot yield was greatest for 100.ft2and least for 70-ft2/acre stands. Burton 1980. USDA For. Serv. Res. Pap. SO-159. 27p. 1980.
Promoting
old-growth characteristics and long-term wood production in Douglas-fir forests
R.T. Busing
Forestry
Sciences Laboratory, 3200 SW Jefferson Way, Corvallis, OR 97331, USA
S.L.
Garmanb
Department
of Forest Science, 321 Richardson Hall, Oregon State University, Corvallis, OR
97331, USA
Abstract
Trade-offs among wood production, wood quality and ecological characteristics in
the management of harvested forest stands a-re explored through model simulation
of various silvicultural regimes. Long-term production of merchantable wood,
production of various types of hi.-h-quality wood, and the level of certain
quantitative ecological indicators are projected for coniferous forests of
Pacific Northwestern USA. The set of ecological indicators used is based on the
species composition and physical structure of old, unlogged forest stands.
Simulations are performed with an ecological model of forest stand dynamics that
tracks the fate of live and dead trees. Short rotations (<50 years) produce
the least amount of high-quality wood over the multi-century simulation period.
They also fail to generate ecological attributes resembling those of old forest
stands. Production of high-quality wood is moderate to high under all rotations
of 80 years or more; however, most ecological indicators require longer
rotations unless alternatives to clearcutting are applied. Alternatives examined
include retention of 15% cover of live tree canopy at each harvest in
combination with artificial thinning between harvests. Thinning from below can
expedite the development of large live and dead trees, and canopy height
diversity without greatly diminishing wood quantity or quality, Proportional
thinning retains understory stems, thereby expediting the recruitment of
shade-tolerant trees. A possible drawback to thinning, particularly proportional
thinning, is the diminished production of clean-bole wood at rotations of 150
and 260 years. It is concluded that most wood quantity, wood quality and
ecological objectives can be met with long rotations (ca. 260 years). certain
objectives can be met with shorter rotations (80-150 years) when treatments of
thinning and canopy tree retention are applied. Busing and Garmanb 2002. For. Ecol. Manage. 160:
161–175. 2002.
Author
Keywords
ecological simulation, forest dynamics, late-successional characteristics,
Pacific Northwest, rotation length, silviculture, wood quality
KeyWords
Plus
pacific-northwest, regimes, oregon
Size-specific mortality, growth, and structure of a Great Smoky
Mountains red spruce population
Richard T Busing, Xinyuan Wu
Graduate Program in Ecology, University of Tennessee, Knowxville, TN
37996-1610, USA
Abstract
Old-growth population dynamics of Picea rubens Sarg. Were studied in a montane spruce-fir forest in North Carolina and Tennessee, Size-class structure fit a semilogarithmic rotated sigmoid curve typical of s stable population. Although the population contained trees of all ages, a large proportion of the population was less than 100 years old; few trees were greater than 350 years old. Mortality rates were estimated from a 2 decade census and from population structure data. For trees above breast height, annual mortality was approximately 1% of the population. Small trees (<30 cm dbh) and large trees (>60cm dbh) had mortality rates exceeding 0.7% per year. Intermediate-sized trees tended to have low mortality rates (<0.5% per year) and high radial growth rates. Growth in the 10-year interval preceding death tended to be slow for standing dead trees. Standing death of canopy trees was more prevalent than death by windfall. These findings emphasized the influence of stand dynamics on spruce growth and mortality. Busing and Wu 1990. Can. J. For. Res. 20: 206-210. 1990.
Application of a spruce-fir forest canopy gap model
R.T. Busing
Department of Botany, University of Tennessee, Knoxville, TN 37996-1100
USA
E.E.C. Clebsch
Graduate Program in Ecology, University of Tennessee, Knoxville, TN 37996-1610 USA
Abstract
A
gap model was developed from the FORET model of Shugart and West (1977) to
simulate stand dynamics of an old-growth spruce-fir forest in the Great Smoky
Mountains, North Carolina and Tennessee. As in FORET, the recruitment, growth and
mortality of individual trees on a gap-size tract are calculated and tabulated
annually. Regeneration algorithms were developed to simulate gap-phase
recruitment of subsamplings. The model was designed for studies of long-term
forest dynamics with and without exogenous disturbance.
The
spruce-fir model was validated by comparing simulated and natural forest
responses to disturbances involving canopy tree mortality. Simulated density and
basal area values were compared to those of actual stands. Absolute and relative
basal area responses were found to be reliable.
The
model was applied to predict future forest stand composition, structure and
dynamics under a variety of potential disturbance regimes including air pollution
stress and aphid-inced fir mortality. In the absence of exogenous
disturbance the model predicted long-term coexistence of
spruce and fir. Simulated balsam woolly aphid infestation of fir resulted
in a spruce-dominated forest with low total stand density. A moderately severe
spurce growth decline in the presence of an undisturbed fir population resulted
in a fir-brich forest. In association with a fir population decline the effects
of spruce growth stress were diminished. The contemporaneous decline of spruce
and fir populations resulted in a hardwood-dominated forest with low stand
biomass. Busing and Clebsch 1987. For. Ecol. Manage. 20: 151-169. 1987.
Estimating
DBH from Stump Diameter for 15 Southern Species
Carl V. Bylin
Renewable
Resources Evaluation, Southern Forest Experiment Station, Forest Service-USDA,
New
Orleans,
Louisiana.
Abstract
Regression
equations for predicting dbh from tree stump diameter inside and outside bark
are presented for 15 southern species. Equations were certified on independent test subsets using the F
distribution statistic with significance level of .05. Bylin 1982. USDA For. Serv. Res. Pap. SO-286. 3p. 1982.
Key
Words
dbh,
stump diameter
Volume Prediction from Stump Diameter and Stump Height of Selected
Species in Louisiana
Carl V.
Renewable
Resources Evaluation, Southern Forest Experiment Station, Forest Service-USDA,
New
Orleans,
Louisiana.
Equations
for predicting cubic foot volumes from stump diameter and stump height are
presented for 15 southern species. Of the two separate sets of equations
developed, one predicts volumes from stump diameter and the other predicts
volume from stump diameter and stump height. In each set, six equations for each
species predict total, merchantable, and sawtimber volumes. Two equations for
each of the above are presented using stump diameter inside bark and stump
diameter outside bark. Equations were verified on independent test subsets using
the F distribution statistic with a significance level of .05. Equations will
predict volume within +/- 2 standard errors 95 percent of the time. Bylie 1982. USDA
For. Serv. Res. Pap. SO-182. 15p. 1982.
Volume,
sawtimber volume, total volume, merchantable volume, stump diameter, stump
height
Complex compatible taper and volume estimation systems for red and
loblolly pine
John C. Byrne
USDA Forest Service, Intermountain Forest and Range Experiment Station,
Moscow, ID 83843
David D. Reed
School of Forestry and Wood Products, Michigan Technological University,
Houghton, MI 49931
Abstract
Five
equation systems are described which can be used to estimate upper stem
diameter, total individual tree cubic-foot volume, and merchantable cubic-foot
volumes to any merchantability limit (expressed in terms of diameter or height)
both inside and out side bark. The equations provided consistent results since
they are mathematically related and are fit using stem analysis data from
plantation-grown red and loblolly pine. Comparisons are made to determine which
equation system provides the best overall fit to a set of validation data for
each species. Results indicate that a system based on a segmented taper equation
outperformed all other systems for both species. Byrne and Reed 1986. For. Sci. 32: 423-443. 1986.
Additional
key words
Pinus resinosa, pinus taeda
Tools for optimizing management of spatially-variable fields
Laboratory
of Soil Science and Geology, Wageningen University, Duivendaal 1, PO Box 37,
6700 AA Wageningen, The Netherlands
Laboratory
of Soil Science and Geology, Wageningen University, Duivendaal 1, PO Box 37,
6700 AA Wageningen, The Netherlands
Iowa
State University, Ames, IA 50011-3080, USA
Iowa
State University, Ames, IA 50011-3080, USA
Laboratory
of Soil Science and Geology, Wageningen University, Duivendaal 1, PO Box 37,
6700 AA Wageningen, The Netherlands
CORBANA,
Direccio´n de Investigaciones, Apartado 390-7210 Gua piles, Costa Rica
Abstract
Efficient use of agro-chemicals is beneficial for farmers as well as for the
environment. Spatial and temporal optimization of farm management will increase
productivity or reduce the amount of agro-chemicals. This type of management is
referred to as Precision Agriculture, Traditional management implicitly
considers any field to be a homogeneous unit for management: fertilization,
tillage and crop protection measures, for example, are not varied within a
single field. The question for management is what to do it-hen. Because of the
variability within the field, this implies inefficient use of resources.
Precision agriculture defines different management practices to be applied
within single, variable fields, potentially reducing costs and limiting adverse
environmental side effects. The question is not only what and it-hen but also
where. Many tools for management and analysis of spatial variable fields have
been developed. In this paper, tools for managing spatial variability are
demonstrated in combination with tools to optimize management in environmental
and economic terms. The tools are illustrated on five case studies ranging from
(1) a low technology approach using participatory mapping to derive fertilizer
recommendations for resource-poor farmers in Embu, Kenya, (2) an example of
backward modelling to analyze fertilizer applications and restrict nitrogen
losses to the groundwater in the Wieringermeer in The Netherlands, (3) a
low-tech approach of precision agriculture, developed for a banana plantation in
Costa Rica to achieve higher input use efficiency and insight in spatial and
temporal variation, (4) a high-tech, forward modelling approach to derive
fertilizer recommendations for management units in Zuidland in The Netherlands,
and (5) a high-tech, backward modelling approach to detect the relative effects
of several stress factors on soybean yield. Booltink
and Alphen et al. 2001. Agr. Syst. 70: 445-476.
Author Keywords
precision agriculture, management, modelling, prediction, spatial variability,
temporal variability
Key Words Plus
precision agriculture, unsaturated soil, fuzzy-sets, classification,
variability, simulation, scenarios, scale