1. 1987. Impact of intensive forestry practices on net stand
values in
Keywords: release treatments
fertilization
thinning
yield
economics
Abstract: Yield responses
to major silvicultural treatments (regeneration
method, brushing and weeding, spacing and thinning and fertilizer use) are analysed in relation to growth and yield theory, and their
translation into operational use of treatments to increase merchantable vol. is
considered. Data from coastal Douglas fir (Pseudotsuga
menziesii), western hemlock (Tsuga
heterophylla) and western hemlock/Abies
amabilis stands and interior white spruce (Picea glauca), lodgepole pine (Pinus contorta) and wet belt Douglas fir stands are used to
quantify the net present value of treatments in terms of improvement in net
stand values and merchantable vol. Potentially viable treatment options are
identified for each stand type present.
2.
Keywords: genetic tree improvement
yield
wood quality
economics
Abstract: Relationships
between tree traits and tree value for lumber production were investigated. For
the purposes of estimating relative economic weights for use in multitrait selection in coastal Douglas fir (Pseudotsuga menziesii var. menziesii), tree height, diameter at breast height, and
branch diameter were measured on 164 trees (ages 36-66 yr) sampled from 11
intensively managed stands with a wide range of site attributes, growing
conditions, ages and stocking histories in western Washington and Oregon.
Increment cores from a subsample (92) of these trees
were assayed by X-ray densitometry to determine wood density. Bole volume was
derived by summing the log volumes of all logs from each tree. Value of lumber
recovered from each tree was determined in a separate mill study using both
visual and machine stress rated (MSR) grading rules. Multiple linear regression was used to relate tree value to the growth and
wood quality traits. Stem volume and branch diameter significantly influenced
tree value under visual grading, with relative economic weights of 0.06 dmsuperscript 3 and -5.22 cm, respectively. Wood density
significantly influenced tree value under MSR grading (relative economic
weights: 0.06 dmsuperscript 3, -6.69 cm, and 0.06 kg/msuperscript 3, respectively), where lumber strength is
measured more accurately. These regression coefficients can be used directly as
economic weights in selection indices in the development of advanced breeding programmes for Douglas fir.
3. Barbour, R.J.,
Keywords: thinning
yield
wood quality
Abstract:
Hundreds of thousands of hectares of Douglas fir (Pseudotsuga
menziesii) plantations in coastal forests in the US
Pacific Northwest have been 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,
in order to satisfy goals of ecosystem management. 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 forest management policy
associated with these types of regimes raise questions about whether it is
possible to manage for both ecosystem values and timber production.
State-of-the-art growth models were used to simulate stand development 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. It is concluded that it should be possible to manage Douglas
fir plantations to provide a high degree of structural diversity, and wood
products with a quality similar to that grown in many industrial plantations.
4. Busing, R.T. and S.L. Garman.
2002. Promoting old-growth characteristics and long-term wood production in
Douglas-fir forests. Forest-Ecology-and-Management 160(1/3): 161-175.
Keywords: thinning
yield
wood quality
Abstract: Trade-offs
among wood production, wood quality and ecological characteristics in the
management of harvested forest stands are explored through model simulation of
various silvicultural regimes. Long-term production
of merchantable wood, production of various types of high-quality wood, and the
level of certain quantitative ecological indicators are projected for
coniferous forests of Pacific Northwestern USA. The set of ecological
indicators used is based on the species composition and physical structure of
old, unlogged forest stands. Simulations are
performed with an ecological model of forest stand dynamics that tracks the
fate of live and dead trees. Short rotations (<50 years) produce the least
amount of high-quality wood over the multi-century simulation period. They also
fail to generate ecological attributes resembling
those of old forest stands. Production of high-quality wood is moderate to high
under all rotations of 80 years or more; however, most ecological indicators
require longer rotations unless alternatives to clear felling are applied.
Alternatives examined include retention of 15% cover of live tree canopy at
each harvest in combination with artificial thinning between harvests. Thinning
from below can expedite the development of large live and dead trees, and
canopy height diversity without greatly diminishing wood quantity or quality.
Proportional thinning retains understorey stems,
thereby expediting the recruitment of shade-tolerant trees. A possible drawback
to thinning, particularly proportional thinning, is
the diminished production of clean-bole wood at rotations of 150 and 260 years.
It is concluded that most wood quantity, wood quality and ecological objectives
can be met with long rotations (approximately 260 years). Certain objectives
can be met with shorter rotations (80-150 years) when treatments of thinning
and canopy tree retention are applied.
5. Cahill, J.M., T.A. Snellgrove and T.D. Fahey. 1988. Lumber and veneer recovery
from pruned Douglas-fir. Forest-Products-Journal 38(9): 27-32.
Keywords: pruning
yield
wood quality
Abstract: Logs were
selected from a 75-yr-old stand of Douglas fir (Pseudotsuga
menziesii) in
6. Cameron, I.R. 1988. An evaluation of the density management diagram for coastal
Douglas-fir. BC Ministry of Forests FRDA-Report 024.
vi + 17 p.
Keywords: planting operations
growth
yield
Abstract: Yield
predictions based on Drew and Flewelling's (1979)
density management diagram for coastal Douglas fir (Pseudotsuga
menziesii) were compared with remeasured
plot data from
7. Comeau,
P. and D. Sachs. 1992. Simulation of the consequences of red alder management
on the growth of Douglas-fir using FORCYTE-11. B.C. Ministry
of Forests FRDA Report 187. 45 p.
Keywords: planting operations
yield
computer modeling
Abstract: The
ecosystem model FORCYTE-11 was used to investigate the effects of initial red
alder (Alnus glutinosa)
density on yields of Pseudotsuga menziesii
and alder over a 80-year rotation, the effects of
delayed planting of red alder on stand yields, and the effects of 5 management
strategies on the total yield over a 240-year period.
8. Curtis, R.O., G.W. Clendenen and D.J. DeMars. 1981.
A new stand simulator for coast Douglas-fir: DFSIM user's guide. Pacific-Northwest-Forest-and-Range-Experiment-Station,-USDA-
Keywords: planting operations
thinning
precommercial thinning
commercial thinning
fertilization
yield
computer modeling
Abstract: A
description of a computer program, written in FORTRAN IV, for simulating
managed stands. The program has been developed from remeasured
plot data contributed by many organizations in the Pacific Northwest USA. It
can produce yield tables which include estimates of effects of initial spacing,
precommercial and commercial thinning and addition of
N fertilizer. Topics discussed include program limitation and potential for
further development. Appendices include operating instructions and notes on
testing. The program is available from the authors on request.
9. Curtis, R.O. and D.D. Marshall.
2002. Levels-of-growing-stock cooperative study in Douglas-fir: report no. 14 -
Stampede Creek: 30-year results. Pacific-Northwest-Research-Station,-USDA-
Keywords: thinning
commercial thinning
growth
yield
tree morphology
tree/stand health
Abstract: Results
of the Stampede Creek installation of the levels-of-growing-stock (LOGS) study in
Douglas-fir (Pseudotsuga menziesii)
are summarized. To age 63 (planned completion of 60 feet of height growth), volume growth on the site III natural stand has been
strongly related to level of growing stock, but basal area growth-growing stock
relations were considerably weaker. Marked differences in tree size
distributions have resulted from thinning. Periodic annual volume increments at
age 63 are two to three times greater than mean annual increment; this stand is
still far from culmination. Results for this southwest
10. Curtis, R.O., D.D. Marshall and
J.F. Bell. 1997. LOGS: a pioneering example of silvicultural
research in coast Douglas-fir. Journal-of-Forestry 95(7): 19-25.
Keywords: thinning
commercial thinning
growth
yield
Abstract: A
regional levels-of-growing-stock (LOGS) study of young Douglas fir (Pseudotsuga menziesii) stands in
western
11. Duryea, M.L. and S.K. Omi. 1987.
Top pruning Douglas-fir seedlings: morphology, physiology, and field
performance. Canadian-Journal-of-Forest-Research 17(11): 1371-1378.
Keywords: nursery operations
nursery pruning
tree phenology
tree/stand health
growth
yield
Abstract:
Seedlings from 9 seed sources at 6 nurseries in Washington, Oregon and
California were treated with various pruning treatments including tall and
short ht. (25 and 15 cm, respectively), early and late timing (6 wk after bud
burst or 6 wk after bud set, respectively), pruning twice or no pruning.
Seedlings were evaluated for phenology and quality,
and graded in the nursery. For each seed source, seedlings were planted at
field sites in their own zone and on one common site. Seedlings pruned tall and
early began growing again within 5 wk and set buds 2 wk later than unpruned seedlings. Shippable yield of seedlings pruned
tall and early and of unpruned seedlings were n.s.d, although more pruned seedlings had multiple leaders.
Pruned seedlings were smaller than unpruned seedlings
at the time of planting. Survival and growth were the same for pruned and unpruned seedlings in the 1st year after planting. Pruned
seedlings grew more than unpruned seedlings in the
2nd year, but were still shorter after 2 yr. Field growth was greater in
seedlings pruned tall or early than in seedlings pruned short or late. It is
concluded that pruning should be continued as a cultural practice if it
benefits nurseries, but that late short pruning should be avoided.
12. Emmingham,
W.L., P. Oester, M. Bennett, F. Kukulka,
K. Conrad and A. Michel. 2002. Comparing short-term financial aspects of four
management options in
Keywords: thinning
commercial thinning
economics
yield
Abstract: Private
family forest owners are often more interested in comparing short-term
financial outcomes of management options, as opposed to longer time horizons
and classical economic analyses including net present value. Therefore, we
compared projected 10-year value of timber and land for four theoretical
management scenarios starting with stands ripe for thinning. The options were
(1) hold for 10 years (i.e. no thinning), (2) thin for even-age, or (3) partial
cut for uneven-age and (4) clearcut now. To simulate
the outcomes of these scenarios, we marked and measured 2-ha plots
in 10 stands typical of private forest ownerships across
13. Fight, R.D., J.M. Cahill, T.D.
Fahey and T.A. Snellgrove. 1987a. Financial
analysis of pruning coast Douglas-fir. Pacific-Northwest-Research-Station,-USDA-
Keywords: pruning
fertilization
economics
wood quality
yield
computer modeling
Abstract: Unpruned stands of Douglas fir (Pseudotsuga
menziesii) will yield little clear material under
current management regimes in western
14. Fight, R.D., J.T. Chmelik and E.A. Coulter. 2001. Analysts guide: TreeVal for Windows, Version 2.0. Pacific-Northwest-Research-Station,-USDA-
Keywords: pruning
economics
wood quality
yield
Abstract: TreeVal for Windows
provides financial information and analysis to support silvicultural
decisions in coast Douglas-fir (Pseudotsuga menziesii). It integrates the effect of growth and yield,
management costs, harvesting costs, product and mill type, manufacturing costs,
product prices, and product grade premiums. Output files from the ORGANON
growth and yield simulator can be read directly into TreeVal.
All management actions, including pruning, are supported. Results, including
product recovery information, net value, and financial analysis of silvicultural regimes, are available in both tabular and
graphical forms to facilitate comparison of alternative regimes and sensitivity
analysis with prices, costs, and other assumptions.
15.
Keywords: fertilization
thinning
growth
yield
tree morphology
tree/stand health
Abstract:
Responses after 15 yr to 3 rates of nitrogen (urea),
applied at 0, 224 or 448 kg N/ha to a 24-yr-old Douglas fir (Pseudotsuga menziesii) stand in
the very dry maritime region of
16. Garman, S.L., J.H. Cissel and J.H. Mayo. 2003. Accelerating development of
late-successional conditions in young managed
Douglas-fir stands: a simulation study. Pacific-Northwest-Research-Station,-USDA-
Keywords: thinning
commercial thinning
yield
Abstract: The
goal of this simulation study was to provide information for defining thinning
regimes for young Douglas-fir (Pseudotsuga menziesii) stands in the Central Cascades Adaptive
Management Area, located in west-central
17. Haight,
R.G. 1993b. Technology change and the economics of silvicultural investment.
Rocky-Mountain-Forest-and-Range-Experiment-Station,-USDA-
Keywords: planting operations
site preparation
prescribed fire
release treatments
chemical release
tree/stand protection
thinning
commercial thinning
precommercial thinning
yield
economics
Abstract: Financial
analyses of intensive and low-cost reforestation options are conducted for
loblolly pine (Pinus contorta)
stands with broadleaved competition in the Southern USA, and Douglas fir with
red alder (Pseudotsuga menziesii
with Alnus rubra) in the
Pacific Northwest. Results show that the expected present values (EPVs) of low-cost options that result in mixtures of
conifers and broadleaves are superior in some situations to the EPVs of the intensive options.
18. Hermann, R.K. and D.P. Lavender.
1999. Douglas-fir planted forests. New-Forests 17(1/3): 53-70.
Keywords: genetic tree improvement
nursery operations
planting operations
site preparation
release treatments
fertilization
thinning
pruning
tree/stand protection
growth
yield
Abstract: A
combination of superior wood quality and high productivity has made Douglas fir
(Pseudotsuga menziesii) one
of the premier timber trees in the world. As such, it is grown as a plantation
species in several countries in
19. Hummel, S. and R. Hummel. 2004.
Five-year thinning response of an overgrown Douglas-fir Christmas tree
plantation. Western-Journal-of-Applied-Forestry 19(3): 171-174.
Keywords: planting operations
thinning
growth
yield
economics
Abstract: A
15-year-old Douglas-fir Christmas tree plantation in western
20. King, J.E., D.D. Marshall and
J.F. Bell. 2002. Levels-of-growing-stock cooperative study in Douglas-fir:
report no. 17 - the Skykomish study, 1961-93; the
Clemons study, 1963-94. Pacific-Northwest-Research-Station,
USDA-Forest-Service Research-Paper PNW-RP-548. vii
+ 120 p.
Keywords: thinning
commercial thinning
growth
yield
tree/stand health
Abstract: A study
was conducted at the Skykomish Tree Farm, and at the
Clemons Tree Farm,
21. Knapp, W.H., T.C. Turpin and J.H.
Beuter. 1984. Vegetation control for Douglas-fir
regeneration on the
Keywords: planting operations
site preparation
chemical preparation
mechanical preparation
prescribed fire
release treatments
chemical release
manual release
growth
yield
economics
Abstract: Records
from 324 plantations in
22.
Keywords: planting operations
release treatments
yield
economics
Abstract: Models
indicated that the yield and net present value (NPV) of young Pseudotsuga menziesii stands in
23. Kramer, H. and J.H.G. Smith.
1985. Establishment of Douglas fir stands in
Keywords: planting operations
thinning
pruning
growth
yield
economics
wood quality
Abstract: Square
spacing trials were established NW of Haney (180 m alt.) at 0.91, 1.83, 2.74,
3.66 and 4.57 m. Growth to age 25 yr, and simulation estimates up to 100 yr are
reported. Results indicated that extra costs (incurred by thinning) of stands
closer than 4 m spacing are difficult to justify in economic terms, because the
market for Douglas fir timber grown in British Columbia is such that only
production of large timber is economically viable. The quality of timber from
trees grown at wide spacing without thinning is acceptable in relation to
Canadian requirements, and could be improved if wide spacing were combined with
pruning. It is recommended that close spacings be
used only if availability of land is limited or demand for biomass is very
strong.
24. Marshall, D.D. and R.O. Curtis.
2002. Levels-of-growing-stock cooperative study in Douglas-fir: report no. 15 -
Hoskins: 1963-1998. Pacific-Northwest-Research-Station,-USDA-
Keywords: thinning
commercial thinning
growth
yield
tree/stand health
tree morphology
Abstract: The
cooperative levels-of-growing-stock (LOGS) study in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) was begun to study the relations between
growing stock, growth, cumulative wood production, and tree size in repeatedly
thinned stands. This report summarizes results from the Hoskins installation
through age 55. Growing stock has been allowed to accumulate for 19 years since
the last treatment thinning was applied in this high site class II natural
stand. Volume and diameter growth were strongly related to growing stock. Basal
area growth-growing stock relations were considerably weaker. Differences in tree
size and volume distribution were considerable. Culmination of mean annual
increment has not occurred for any of the treatments, although the control has
culminated for total stem cubic volume and is near culmination for merchantable
cubic volume. Only small differences are seen in growth percentages between
thinning treatments. Results demonstrate potential flexibility in managing
Douglas-fir to reach a range of objectives.
25. Miller, M. and B. Emmingham. 2001. Can selection thinning convert even-age
Douglas-fir stands to uneven-age structures?
Western-Journal-of-Applied-Forestry 16(1): 35-43.
Keywords: thinning
commercial thinning
growth
yield
tree/stand health
regeneration
Abstract:
Uneven-age management of Douglas-fir (Pseudotsuga menziesii) stands can be used to address aesthetic,
wildlife habitat, biodiversity and sustainability concerns, but there has been
little long-term experience with this type of management. To develop timely
information on converting even-age stands to uneven-age forests, we used
retrospective stand reconstruction methods to document harvest frequency,
intensity and stand structural development at four sites in western
26. Miller, R.E., R.E. Bigley and S. Webster. 1993a. Early
development of matched planted and naturally regenerated Douglas-fir stands
after slash burning in the
Keywords: planting operations
growth
yield
Abstract: Comparisons
were made of matched planted and naturally regenerated plots in 35- to
38-yr-old Douglas fir (Pseudotsuga menziesii var. menziesii) stands
at seven locations in western
27. Miller, R.E., E.L. Obermeyer and H.W. Anderson. 1999. Comparative effects of precommercial thinning, urea fertilizer, and red alder in a
site II, coast Douglas-fir plantation. Pacific-Northwest-Research-Station,-USDA-
Keywords: fertilization
thinning
precommercial thinning
growth
yield
tree/stand health
soil properties
Abstract: The
number of red alder (Alnus rubra)
trees retained with 300 Douglas-fir (Pseudotsuga menziesii) per acre was varied on a high-quality site in
coastal
28. Mitchell, K.J. and J.R. Cameron.
1985. Managed stand yield tables for coastal Douglas-fir: initial density and precommercial thinning. Ministry-of-Forests, British-Columbia
Keywords: planting operations
thinning
precommercial thinning
growth
yield
Abstract: Yield
tables are presented for second growth stands of Pseudotsuga
menziesii, established naturally (4440 trees/ha) or
planted with 300, 500, 750, 1110 or 2500 trees/ha in
29. Murray, M.D. 1988. Growth and yield of a managed 30-year-old noble fir plantation.
Pacific-Northwest-Research-Station,-USDA-Forest-Service
Research-Note PNW-RN-475. 8 p.
Keywords: planting operations
growth
yield
economics
Abstract: Yield
of noble fir (Abies procera)
from a managed (urea application 15 yr after planting, precommercially
thinned after 17 and 24 yr) stand in the Doty Hills, western Washington was
measured and compared with the simulated yield of a Douglas fir (Pseudotsuga menziesii) plantation
of the same age. Noble fir produced 3450 ftsuperscript
3/acre at age 30 yr; more than half this volume was in trees of <more or
=>10 inches d.b.h. Current annual increment during
the 6 yr after the second thinning (to 300 trees/acre) was 295 ftsuperscript 3/acre. Ornamental boughs had been harvested
annually for 15 yr. Total noble fir volume was about 5% less than the simulated
volume of Douglas fir. The estimated value of noble fir after 48 yr, including sawlogs and boughs, could exceed the value of Douglas fir
at the same age grown on the same site.
30. O'-Hara, K.L. 1990. Twenty-eight
years of thinning at several intensities in a high-site Douglas-fir stand in
western
Keywords: thinning
commercial thinning
growth
yield
Abstract: Results
are presented of a 28-year thinning study of a dense (182-452 tree/acre)
natural, second growth Douglas fir (Pseudotsuga menziesii) stand at Delezenne,
which compared 3 thinning treatments with an unthinned
control. Treatments were: an increasing basal area treatment; a constant basal
area treatment (of approximately 140 ftsuperscript
2/acre); a decreasing/increasing reserve basal area treatment; and control
plots, which were 35 to 37-years-old with basal area 80-203 ftsuperscript
2/acre in 1957 when the tests were started. Gross, net, and total recoverable
periodic cubic volume increments of the control treatment (10 396, 9108 and 16
092 ftsuperscript 3/acre, respectively) were not
significantly different from the highest yielding treatment, which was the
increasing reserve basal area thinning treatment (8896, 8594 and 16 636 ftsuperscript 3/acre, respectively). These results, and
options for thinning schedules, are discussed; it is suggested that commercial thinnings of dense or fully stocked plantations of Douglas
fir may produce similar results, that is, vigorous stands with rapid growth
potential.
31. O'-Hara, K.L. and C.D. Oliver.
1988. Three-dimensional representation of Douglas-fir volume growth: comparison
of growth and yield models with stand data. Forest-Science 34(3): 724-743.
Keywords: planting operations
thinning
growth
yield
computer modeling
Abstract: Growth
and yield estimates for unthinned stands from the
Douglas fir Stand Simulator (DFSIM) and the Tree and Stand Simulator (TASS)
were used to construct graphical three-dimensional representations of Douglas
fir (Pseudotsuga menziesii)
stand growth on site index 44 m (50 yr). The three-dimensional models used
three variables: trees per hectare, b.h. age, and
either mean tree vol. or stand vol. The TASS and DFSIM models were in agreement
over most of their common range of age and number of trees. At wider spacings and older ages, however, the volumes predicted by
the DFSIM model exceeded those predicted by the TASS model by as much as 25%.
Comparisons of these three-dimensional models to unthinned
and thinned stand data from a site of similar quality in the Delezenne thinning trial,
32. Omule,
S.A.Y. 1984. Results from a correlated curve trend experiment on spacing and
thinning of coastal Douglas fir. B.C. Ministry-of-Forests
Research-Note 93. ix + 22 p.
Keywords: thinning
precommercial thinning
growth
yield
tree/stand health
Abstract: Plots were
established in 1952 in 13-yr-old plantations and given a variety of thinning
treatments to produce post-thinning densities of 125-3000 stems/ha. Trees were
measured at intervals up to 1980. Analysis showed that diam.,
ht. and their growth increased with decrease in density. Mortality, b.a., total vol. and b.a. growth decreased as density decreased. Stand
merchantable vol. was not affected by density except at extremes. Prolonged
early suppression appeared to reduce the ability of a stand to respond to subsequent
thinning in terms of b.a.
and total vol.
33. Omule, S.A.Y. 1987b. Early growth of four species planted at
three spacings on
Keywords: planting operations
tree/stand health
growth
yield
Abstract: Seedling
survival and 24- to 26-yr growth were measured of (a) Douglas fir (Pseudotsuga menziesii), (b)
western hemlock (Tsuga heterophylla),
(c) Sitka spruce (Picea sitchensis)
and (d) Thuja plicata grown
at 2.7x2.7, 3.7x3.7 and 4.6x4.6 m spacings on the W.
coast of Vancouver Island, British Columbia. Initial spacing had no significant
effect on survival, which was 86% in (a), 56% in (b), 87% in (c) and 91% in
(d). Effects of spacing on growth and yield were as expected (little effect on ht.; wider spacings produced
larger trees, but vol./ha was lower) in (a), but were delayed or confounded in
(b) by poor seedling survival, in (c) by weevil (Pissodes
strobi) damage and in (d) by salal
(Gaultheria shallon) competition and browsing.
34. Omule, S.A.Y. 1988. Growth and yield 35 years
after commercially thinning 50-year-old Douglas-fir. B.C.
Ministry of Forests FRDA-Report 021. vi + 15 p.
Keywords: thinning
commercial thinning
growth
yield
tree/stand health
Abstract: Remeasurement data
over a period of 35 years from fourteen 0.2023-ha permanent plots were analysed to determine the growth and yield effects of
commercially thinning 50-year-old Douglas fir (Pseudotsuga
menziesii) stands on a good site on Vancouver Island,
British Columbia. Compared to unthinned stands, the
commercially thinned stands had: virtually the same total volume gross annual
increment, top height and top height increment; 12% more potentially usable
total volume yield (including thinnings); 18% less
total volume at final harvest age 86 yr; virtually the same crop tree (193
largest diameter trees per hectare) average diameter, but 24% larger entire
stand quadratic mean diameter; and 11% less total volume production lost to
mortality. These results show that commercial thinning slightly increased total
stand yield (including thinnings) and produced larger
stand diameter at rotation age 86 yr, but that it also reduced usable total
volume at final harvest and had virtually no effect on size of the crop trees.
Data from this study are useful for validating growth models, and for
constructing and comparing managed stand yield tables for various commercial
thinning regimes.
35. Ralston, R., J. Buongiorno and J.S. Fried. 2004. Potential yield, return,
and tree diversity of managed, uneven-aged Douglas-fir stands. Silva-Fennica 38(1): 55-70.
Keywords: thinning
commercial thinning
economics
yield
Abstract: The effects
of different management regimes on uneven-aged Douglas-fir stands in the
36. Reukema, D.L. and J.H.G. Smith. 1987. Development over 25 years of
Douglas-fir, western hemlock, and western redcedar
planted at various spacings on a very good site in
Keywords: planting operations
pruning
growth
yield
tree morphology
Abstract: Five
spacing trials were established during 1957-67 at the University of British Columbia Research Forest, covering a range of spacings from 1 to 5 m and of experimental designs
(49-tree-plot, 0.2-ha plot, rectangularity, Nelder
and variable block trials). Results showed that initial spacing is among the
most important factors influencing stem and crown development, and stand growth
and yield for Douglas fir (Pseudotsuga menziesii), western hemlock (Tsuga
heterophylla) and western redcedar
(Thuja plicata). Top
heights were initially taller at closer spacings, but
are now similar at all spacings. Av. ht. is now
shorter at close spacing. Decreases in heights to dead and live crowns and
increases in diam. of lower stem, taper and crown
size occurred as spacing increased. B.a.
and stand vol. increased as spacing decreased until onset of density-related
mortality. It is concluded that initial wide spacings
with rectangularities up to 2:1 (e.g. 6x3 m) will
result in efficient production of large trees of high value and satisfactory
quality. Pruning of widely spaced trees to enhance lower stem quality is
strongly recommended.
37. Riitters,
K. and J.D. Brodie. 1984. Implementing optimal
thinning strategies. Forest-Science 30(1): 82-85.
Keywords: thinning
economics
growth
yield
Abstract: [See FA
41, 3436; 44, 201] A method is described for comparing the results of optimal
thinning analyses based on different management or economic criteria (such as
soil expectation value, forest rent or m.a.i.).
Optimal thinning regimes for Douglas fir and ponderosa pine were calculated
using dynamic programming algorithms based on 2 stand growth simulators.
Residual mean tree volumes were then plotted against stand density at varying
time intervals. On a graph of this kind, the time trajectory of optimal
thinning regimes for even-aged stands is approximately parallel to the line of
maximum size/density.
38. Sachs, D. and P. Sollins. 1986. Potential effects of management practices on
nitrogen nutrition and long-term productivity of western hemlock stands.
Forest-Ecology-and-Management 17(1): 25-36.
Keywords: thinning
commercial thinning
yield
soil properties
computer modeling
Abstract: The FORCYTE-10 computer model, developed by J.P. Kimmins and K. Scoullar for
Douglas-fir forests in
39. Sachs, D. and J.A. Trofymow. 1991. Testing the performance of FORCYTE-11
against results from the
Keywords: fertilization
thinning
precommercial thinning
growth
yield
tree physiology
carbon allocation
tree/stand health
computer modeling
Abstract: FORCYTE-11 is an ecosystem-based forest growth simulation
model. Its performance was evaluated with data on stand and tree biomass,
height, stocking (mortality) and foliar assimilation and loss rates for Douglas
fir (Pseudotsuga menziesii)
in thinning/fertilizer trials in
40. Sonne, E., E. Turnblom, D. Briggs and
G. Becker. 2004. Log and lumber grades and value from a Douglas-fir stand 20
years after thinning and biosolids fertilization.
Western-Journal-of-Applied-Forestry 19(1): 34-41.
Keywords: fertilization
thinning
economics
yield
wood quality
Abstract: Three
replications of four treatments: biosolids fertilizer
application, thinning, thinning plus biosolids
fertilizer application, and untreated control were established in 1977 in a
dense, low site, 55-year-old Douglas-fir (Pseudotsuga
menziesii) stand in western Washington, USA. In 1998,
12 trees from each treatment were harvested, bucked into logs, and sawn into
visually graded lumber. Taking into account effects of treatments on stand
yield and log grades, biosolid fertilizer application
only, thinning only, and thinning combined with biosolids
increased log value/ac by $1142 (19%), $3642 (62%), and $9969 (155%),
respectively, over the untreated control. When treatment effects were viewed in
terms of changes in lumber yield and quality, per acre gains over the control
were $2107 (26%), $5683 (70%), and $10 708 (132%), respectively. Willingness to
pay analysis indicates that if the landowner intends to manage the stand to a
rotation of approximately 75 years, each of the treatments, and especially the
combination of thinning and applying biosolids,
appears to be financially attractive at both 5 and 9% interest rates. However,
if the rotation had been set at 55 years, only the thinning/biosolids
combination at 5% interest rate would entice management to delay immediate
harvest.
41.
Keywords: thinning
growth
yield
wood quality
Abstract: Results
are presented from four of the Port Blakely XT series of thinning trials,
established during 1948-58 in naturally regenerated Douglas fir [Pseudotsuga menziesii] stands in
western
42. Stone, M. 1993. An economic evaluation of commercial thinning
Douglas-fir in the coastal region of
Keywords: thinning
commercial thinning
economics
growth
yield
Abstract: The
economic evaluation of commercial thinning of Douglas fir [Pseudotsuga
menziesii] in the coastal region of
Non-OSU
Link
43. Tappeiner, J.C., J.F. Bell and J.D. Brodie.
1982. Response of young Douglas-fir to 16 years of intensive thinning.
Forest-Research-Laboratory,-
Keywords: thinning
growth
yield
tree/stand health
economics
Abstract: The
report of the thinning study in the
44. Tarrant, R.F., B.T. Bormann, D.S. DeBell and W.A.
Atkinson. 1983. Managing red alder in the Douglas-fir region: some
possibilities. Journal-of-Forestry 81(12): 787-792.
Keywords: planting operations
fertilization
yield
economics
Abstract: An
economic comparison of 3 systems for growing Alnus rubra (rotations of 13,20 and 28 yr) in the Pacific
Northwest USA, with or without alternating rotations (45 yr) of Douglas fir,
and 2 continuous systems for growing Douglas fir (45-yr rotations with or
without treatment with N fertilizer). Anticipated stand yield, and costs of
site preparation, planting, fertilization etc. were used to estimate m.a.i. (vol.), present net worth and internal rate of
return. The 2 most profitable systems were Douglas fir, thinned and treated
with fertilizer twice in 45 yr (present net worth $623/acre) and red alder
grown to sawlog size (28 yr) alternating with Douglas
fir thinned twice in 45 yr (present net worth $578/acre). The least profitable
system was red alder grown continuously in 13 yr rotations (present net worth
-$251/acre). Alternate cropping of red alder and Douglas fir or continuous red
alder production would be as profitable as growing Douglas fir alone if there
were increases in real interest rate, alder stumpage price, or the cost of N
fertilizer, or alder sawlog rotation length
decreased.
45.
Keywords: fertilization
thinning
pruning
tree/stand protection
growth
yield
tree/stand health
Abstract: The
Warm Springs Indian Reservation,
Non-OSU
Link
46. Walstad, J.D., J.D. Brodie, B.C.
McGinley and
Keywords: release treatments
chemical release
growth
yield
economics
Abstract: Retrospective
analyses were made of 3 Douglas fir plantations (age 12-39 yr) in western
47. Wang, T., S.N. Aitken, J.H. Woods, K. Polsson
and S. Magnussen. 2004. Effects of inbreeding on
coastal Douglas fir growth and yield in operational plantations: a model-based
approach. Theoretical-and-Applied-Genetics 108(6): 1162-1171.
Keywords: genetic tree improvement
seed orchard management
planting operations
yield
Abstract: In advanced
generation seed orchards, tradeoffs exist between genetic gain obtained by
selecting the best related individuals for seed orchard populations, and
potential losses due to subsequent inbreeding between these individuals.
Although inbreeding depression for growth rate is strong in most forest tree
species at the individual tree level, the effect of a small proportion of inbreds in seed lots on final stand yield may be less
important. The effects of inbreeding on wood production of mature stands cannot
be assessed empirically in the short term, thus such effects were simulated for
coastal Douglas fir [Pseudotsuga menziesii
var. menziesii (Mirb.) Franco] using an individual-tree growth and yield model TASS (Tree
and Stand Simulator). The simulations were based on seed set, nursery
culling rates, and 10-year-old field test performance for trees resulting from
crosses between unrelated individuals and for inbred trees produced through
mating between half-sibs, full-sibs, parents and offspring and self-pollination.
Results indicate that inclusion of a small proportion of related clones in seed
orchards will have relatively low impacts on stand yields due to low
probability of related individuals mating, lower probability of producing
acceptable seedlings from related matings than from
unrelated matings, and a greater probability of
competition-induced mortality for slower growing inbred individuals than for outcrossed trees. Thus, competition reduces the losses
expected due to inbreeding depression at harvest, particularly on better sites
with higher planting densities and longer rotations. Slightly higher breeding
values for related clones than unrelated clones would offset or exceed the
effects of inbreeding resulting from related matings.
Concerns regarding the maintenance of genetic diversity are more likely to
limit inclusion of related clones in orchards than inbreeding depression for
final stand yield.
48. Weetman, G.F., C.E. Prescott, F.L. Kohlberger
and R.M. Rournier. 1997. Ten-year growth response of coastal Douglas-fir on
Keywords: fertilization
growth
yield
tree physiology
Abstract: A
27-year-old stand of coastal Douglas fir (Pseudotsuga
menziesii) on Vancouver Island, British Columbia, was
fertilized four times (1981, 1983, 1986 and 1988) with N as urea at six rates
from 0 to 250 kg N/ha, with and without S coating (0-50 kg/ha). Current-year
foliage was collected annually during 1981-85 and in 1990. Foliar N levels
declined in the control plots over the 10-year period, but remained elevated in
the fertilized plots. The increase in foliar N concentrations was commensurate
with the amount of N added. Stand basal area response increased with increasing
rates of N addition. The greatest response in relative basal area net increment
was 4.52 msuperscript 2/ha (40%) in plots that
received a total of 1000 kg N/ha during the 10 years. Over a 60-year rotation,
about 62 msuperscript 3 of extra wood would be
produced under this regime. There was no additional response to S added in
conjunction with N, so the N + S plots received only a single application of
fertilizer. Mortality was confined to smaller suppressed stems, mostly of
species other than Douglas fir. Foliar N concentrations and basal area
increment declined steadily following cessation of fertilizer application in
these plots, but remained greater than those in control plots for the 10-year
measurement period. The results suggest that sustained increases in growth
response of Douglas fir can be achieved through repeated additions of N that
maintain elevated concentrations of N in foliage.
49.
Keywords: planting operations
thinning
yield
tree morphology
economics
tree/stand health
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