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.