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: fertilization
economics
Abstract: A large
scale pilot study to determine the potential of hand fertilizing forest stands
in western
3. Atkinson, W.A. 1981. Preliminary guidelines for fertilizing less than fully stocked
stands and mixed species stands. In Conference Proceedings:
Keywords: fertilization
economics
Abstract: Foresters
engaged in selecting areas for operational fertilization rarely encounter the
fully stocked pure-species Douglas-fir stands that are studied by researchers.
Most often the question is one of establishing minimal standards for choosing
stands to fertilize. This paper offers preliminary guidelines for fertilizing
less than fully stocked stands and mixed-species stands. Results are presented
by age and site, and consist of a table showing minimal basal area stocking
required to earn a given interest rate.
4. Bailey, V.L., J.L. Smith and H.
Bolton, Jr. 2002. Fungal-to-bacterial ratios in soils investigated for enhanced
C sequestration. Soil-Biology-and-Biochemistry 34(7): 997-1007.
Keywords: fertilization
soil properties
Abstract: Fungi
and bacteria govern most of the transformations and ensuing long-term storage
of organic C in soils. We assessed the relative contributions of these two
groups of organisms to the microbial biomass and activity of soils from five
different ecosystems with treatments hypothesized to enhance soil C
sequestration: (1) desert (an elevation gradient allowed comparison of soil
developed in a cooler, wetter climate with soil developed in a warmer, drier
climate), (2) restored tallgrass prairie (land reverted to native prairie in
1979 and neighbouring land farmed to row crops for ~100 year), (3,4) two forest
types (Douglas fir [Pseudotsuga menziesii] and loblolly pine [Pinus taeda],
unfertilized control and N-fertilized plots), and (5) agricultural land (conventional-
and no-till management systems). The selective inhibition technique, using
captan (fungicide) and oxytetracycline hydrochloride (bactericide), was used to
determine the activities (respiration) of fungi and bacteria in each of these
soils and substrate-induced respiration was used to measure total active soil
microbial biomass C. Phospholipid fatty acid analysis was used to determine the
composition of the soil microbial biomass and determine if the activities and
structure of the microbial communities were related. Differences in
fungal-to-bacterial (F:B) activities between
treatments at a site were greatest at the prairie sites. The restored prairie
had the highest F:B (13.5) and high total C (49.9 g C
kg-1 soil); neighbouring soil farmed to maize had an F:B of 0.85 and total C of
36.0 g C kg-1 soil. Within the pairs of study soils, those that were tilled had
lower fungal activities and stored C than those that were managed to native or
no-till systems. In all pairs of soils, soils that had higher absolute fungal
activities also had more total soil C and when two extreme cases were removed
fungal activity was correlated with total soil C (R2=0.85). Thus, in this small
set of diverse soils, increased fungal activities, more than F:B ratios, were associated with increased soil C. Practices
that involved invasive land management decreased fungal activity and stored
soil C compared to similar soils that were less intrusively managed.
5. Ballard, T.M. 1984. A simple model for predicting stand volume growth response to
fertilizer application. Canadian-Journal-of-Forest-Research 14(5):
661-665.
Keywords: fertilization
growth
Abstract: The equation
R=KTACZQ is used to predict cumulative stand volume growth response (R) to
fertilizer application, where K is a constant and the last 5 (dimensionless)
multipliers represent functions of time, amount of fertilizer applied, stand
composition, stocking, and site quality, respectively. Site-specific input data
requirements are stand composition expressed as percent responding species,
stocking expressed as a percentage of normal stocking, and site index. The
model was calibrated for Douglas-fir response to nitrogen using data from
6. Ballard, T.M. and N. Majid. 1985.
Use of pretreatment increment data in evaluating tree growth response to
fertilization. Canadian-Journal-of-Forest-Research 15(1): 18-22.
Keywords: fertilization
growth
Abstract: The use
of pretreatment increment can lead to improved estimates of individual and
average tree growth response to fertilizing, 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 fertilizing, and
also in estimating responses to operational fertilizing. Equations for
analysing increment response to fertilizing are presented and discussed and 2
particularly useful ones were evaluated by examining branch length increment
data from foliar spray application of iron and copper to Pinus contorta and of
nitrogen and iron to Pseudotsuga menziesii, in field trials in
7. Barclay, H., H. Brix and C.R.
Layton. 1982. Fertilization and thinning effects on a Douglas-fir ecosystem at
Keywords: fertilization
thinning
growth
Abstract: Further
results are given for a trial established in 1970 in a 24-yr-old stand in
8. Barclay, H.J. and H. Brix. 1984.
Effects of urea and ammonium nitrate fertilizer on growth of a young thinned
and unthinned Douglas-fir stand. Canadian-Journal-of-Forest-Research 14(6):
952-955.
Keywords: fertilization
thinning
growth
tree physiology
tree/stand health
Abstract: The
effects were studied of 2 sources of nitrogen fertilizer applied at rates of
224 and 448 kg/ha N on growth of thinned and unthinned plots established in
1970 in a 24-yr-old stand on southern Vancouver Is.,
9. Barclay, H.J. and H. Brix. 1985a.
Effects of high levels of fertilization with urea on growth of thinned and
unthinned Douglas-fir stands. Canadian-Journal-of-Forest-Research 15(4):
730-733.
Keywords: fertilization
thinning
growth
tree physiology
tree/stand health
Abstract: Diameter
height and volume growth were documented for 9 yr after thinning and
fertilizing in a 24-yr-old stand on a poor site on southern Vancouver Is. The
treatments involved 3 thinning treatments (0, 1/3, and 2/3 b.a.
removed) and 6 fertilizer treatments (0-1344 kg/ha N) with urea. Increments for
both diameter and gross volume increased with the rate of fertilizer
application and responses were still apparent 9 yr after treatment. For
unthinned plots, the 9-yr volume growth responses were 30, 50, and 80% with
fertilizer rates of 224, 448, and 896 kg/ha N, respectively. The efficiency of
fertilizer use, measured as stem volume response per unit of nitrogen applied,
decreased with rate of fertilizer application, but this result may change over
a longer response period. There was a positive interaction between fertilizing
and thinning such that high amounts of both mutually enhanced growth. Mortality
increased with fertilizing, but only noticeably in unthinned plots.
10. Barclay, H.J. and H. Brix. 1985b.
Fertilization and thinning effects on a Douglas-fir ecosystem at
Keywords: fertilization
thinning
growth
Abstract: [See FA
45, 2316] Further results are given from the study
established in 1970 in a 24-yr-old stand in
11. Barclay, H.J. and C.R. Layton.
1990. Growth and mortality in managed Douglas fir: relation to a competition
index. Forest-Ecology-and-Management 36(2-4): 187-204.
Keywords: fertilization
thinning
growth
tree/stand health
Abstract: Twelve-year
increments of diameter at breast height (DBH), height, and volume in thinned
and fertilized 45-year-old Douglas fir (Pseudotsuga menziesii) stands on
Vancouver Island, Canada, were related (by regression) to degree of thinning,
amount of fertilizer (3x3 factorial), initial DBH, and a competitive stress
index (CSI). The ability of the CSI to predict growth after treatment was
examined. Causes of tree death, and CSI data, are presented, and the
relationship between them discussed. The CSI was found to be only moderately
good at predicting Douglas fir growth and mortality: initial DBH provided a
better predictor. Most mortality in unthinned plots resulted from suppression,
and correlated reasonably well with CSI; mortality in thinned plots was not
correlated with CSI, and resulted principally from snow damage. Tree height
variability generally became less over the 12 years following treatment, which
is more consistent with two-sided than one-sided competition predictions, a
result which is contrasted to that of many other species.
12. Barclay, H.J., P.C. Pang and
D.F.W. Pollard. 1986. Aboveground biomass distribution within trees and stands
in thinned and fertilized Douglas-fir. Canadian-Journal-of-Forest-Research
16(3): 438-442.
Keywords: fertilization
thinning
carbon allocation
Abstract: Nine
years after heavy thinning and fertilization with urea, 34-yr-old
13. Barclay, H.J. and J.A. Trofymow.
2000. Relationship of readings from the LI-COR canopy analyzer to total
one-sided leaf area index and stand structure in immature Douglas-fir.
Forest-Ecology-and-Management 132(2/3): 121-126.
Keywords: fertilization
thinning
tree morphology
Abstract: Estimation
of leaf area is important in predicting potential growth. This estimation is
often done by means of a photometer, such as the LI-COR plant canopy analyser,
but such instruments generally give biased estimates. Consequently, conversion
factors are required to convert output from the photometer to the actual leaf
area index (LAI). Foliar biomass was estimated in a 52-year-old Douglas fir
(Pseudotsuga menziesii) stand at Shawnigan in
14. Bare, B.B. 1981. Tax effects of
fertilization. In Proceedings:
Keywords: fertilization
economics
Abstract: This
paper describes the sensitivity of investment performance when fertilzization
activities are treated as expensed, capitalized, or amortized expenditures.
Current Internal Revenue Service policy favors capitalization, but pending
revenue rulings are expected to recommend amortization. The impact of these
three alternatives on after-tax cash flows is illustrated by a numerical
example for the Douglas-fir zone of the
15. Binkley, D. and P. Reid. 1984.
Long-term responses of stem growth and leaf area to thinning and fertilization
in a Douglas-fir plantation. Canadian-Journal-of-Forest-Research 14(5):
656-660.
Keywords: fertilization
thinning
tree morphology
carbon allocation
growth
Abstract: Replicated
thinning and nitrogen fertilization plots in a 53-year-old plantation in
16. Binkley, D. and P. Reid. 1985.
Long-term increase of nitrogen availability from fertilization of Douglas-fir.
Canadian-Journal-of-Forest-Research 15(4): 723-724.
Keywords: fertilization
growth
tree physiology
soil properties
Abstract: [See FA
44, 4708; 46, 1837] Most Douglas-fir stands respond to nitrogen fertilizing by
increasing stem growth for less than 8 yr, but one plantation at the United
States Forest Service Wind River Experimental Forest in Washington State has
responded for over 15 yr. In this study nitrogen concn.
of foliage and fresh litter were shown to be higher in
the fertilized plots (470 kg/ha N) 18 yr after fertilizing. Retranslocation of
N from senescent needles was not affected and stem growth per unit N in the
canopy was similar between unfertilized and fertilized plots. An index of soil
N availability in the fertilized plots was twice that of unfertilized plots.
The higher stem growth, leaf area, and stem growth per unit leaf area
demonstrated in an earlier study appeared to be related to a sustained increase
in soil N availability rather than increased N-use efficiency. An examination
of soil N transformation processes is needed to complete the explanation of the
unusually prolonged fertilizer response in these plots.
17. Blake, J., S.R. Webster and S.P.
Gessel. 1988a. Soil sulfate-sulfur and growth responses of
nitrogen-fertilized Douglas-fir to sulfur. Soil-Science-Society-of-America-Journal
52(4): 1141-1147.
Keywords: fertilization
soil properties
growth
Abstract: Two
studies were conducted to determine the growth response of N-fertilized Douglas
fir [Pseudotsuga menziesii (Mirb.) Franco] to S supplements. The relationship
between response and soil SO4-S extracted with Morgan's solution, 1.22 M NaOAc
+ 0.53 M HOAc (pH 4.8), was used to establish critical levels for S. Douglas
fir seedlings were grown in the greenhouse in the surface mineral layer (0 to
0.15 m) of 20 forest soils from western Washington and Oregon. On the average,
significant increases in total dry weight (17.5%), stem diameter (10.1%), and
height (6.9%) occurred when soils were fertilized with N and S in comparison to
N alone. Using the Cate-Nelson procedure, growth responses to N and S were most
likely to occur when soil SO4-S was below 14 mg S kg-1. Twenty eight
installations were established in the field containing five treatments, three
rates of N as urea, and one plot of 336 kg N ha-1 with P, K, Ca, and S.
Differences in percent basal area growth between N alone and N with P, K, Ca,
and S were significantly related to soil SO4-S. Over the initial 5-yr period,
response over N alone was improved by 74% when soil SO4-S was <20 mg S kg-1.
When the N with P, K, Ca, and S plots were retreated with only N and S,
response over the next 3 yr was more than doubled compared with N alone.
Identification of S responsive stands was improved by the inclusion of stand
age weighted subsoil SO4-S concentrations.
18. Blake, J.I., H.N. Chappell, W.S.
Bennett, S.R. Webster and S.P. Gessel. 1990. Douglas fir growth and foliar
nutrient responses to nitrogen and sulfur fertilization. Soil-Science-Society-of-America-Journal
54(1): 257-262.
Keywords: fertilization
tree physiology
growth
Abstract: Nitrogen-fertilizer
response in conifer stands of the Pacific Northwest has been related to soil
and foliar S, and growth has sometimes been enhanced by the addition of S. Five
stands of Douglas fir (Pseudotsuga menziesii) in Washington or Oregon, with low
to moderate quantities of sulfate in the mineral soil horizon, were treated
with N (urea) alone or with S (as ammonium sulfate). The results indicated that
levels of soil sulfate did not provide local or site-specific predictions of
the magnitude of the gain from applying N with S. The observed treatment
effects were highly variable. Foliar N concentrations in the N plus S treatment
were generally higher than in the N treatment. Little change in foliar S
content occurred in the N plus S plot. Periodic annual growth response to N
over the study period was inversely related to site index and directly related
to foliar N content.
19. Bodner, J. 1984. Effect of thinning and fertilization on wood properties and
intra-ring characteristics in young Douglas-fir.
Holzforschung-und-Holzverwertung 36(1): 5-11.
Keywords: fertilization
thinning
wood quality
Abstract: Studies
were made on samples from a total of 21 trees (felled in 1982) from 42-yr-old
control and thinned/[N] fertilizer-treated stands near
20. Briggs, D.G., F. Mecifi and W.R.
Smith. 1986. Effect of sludge on wood properties: a conceptual review with
results from a sixty-year-old Douglas-fir stand. In The forest
alternative for treatment and utilization of municipal and industrial wastes. Ed. D.W. Cole, C.L. Henry, and W.L. Nutter.
Keywords: fertilization
wood quality
Abstract:
Expected changes in wood properties due to cultural practices are reviewed. The
hormone theory and published studies on the effects of thinnings and
fertilizers are used to provide a basis for hypotheses describing the effects
of sludge treatments on wood properties. Notes are given on the effect of
municipal sludge on relative density, tracheid characteristics and strength
properties of Douglas fir.
21. Brix, H. 1984.
Effects of thinning and nitrogen fertilization on growth of Douglas-fir:
relative contribution of foliage quantity and efficiency.
Canadian-Journal-of-Forest-Research 13(1): 167-175.
Keywords: fertilization
thinning
growth
carbon allocation
tree morphology
Abstract: [See FA
43, 1948, 3839] On Vancouver Island, aboveground biomass and annual production
over 7 yr was studied in relation to thinning and
nitrogen fertilization at 24 yr old. Biomass yield of both treatments increased
during the first 3-4 yr then decreased for fertilization but not with thinning.
Treatments doubled biomass production of individual trees over the study period
when applied separately and quadrupled it when combined. Annual biomass
production per unit of foliage (E) increased during the first 3-4 yr, but was
at or below control level after 7 yr. E accounted for 20, 37, and 27% of the
stemwood dry matter response to thinning, fertilization and the combined
treatments, respectively; the remainder was attributed to an increase in
foliage biomass. Thinning, but not fertilization, influenced distribution of
radial growth along the stem, increasing growth only below the top one-third of
the stem. This pattern was related to crown development.
22. Brix, H. 1993. Fertilization and
thinning effect on a Douglas-fir ecosystem at
Keywords: fertilization
thinning
growth
tree morphology
tree/stand health
carbon allocation
wood quality
tree physiology
photosynthesis
economics
Abstract:
Treatments were initiated in 1970-71 in a 24-year-old Douglas fir (Pseudotsuga
menziesii) near Shawnigan Lake, Vancouver Island, British Columbia, to
determine the effects of 3 intensities of thinning (removing none, one-third
and two-thirds of basal area) and 3 levels of urea fertilizer (0, 224 and 448
kg N/ha) on the growth and biology of the trees. Subsidiary experiments were
established during 1972-87 to examine the effects of high doses of urea
(672-1344 kg N/ha), ammonium nitrate as an N source instead of urea,
understorey response to thinning and fertilizer, and responses to P and S
fertilizer.
23. Brix, H. and A.K. Mitchell. 1983.
Thinning and nitrogen fertilization effects on sapwood development and
relationships of foliage quantity to sapwood area and basal area in
Douglas-fir. Canadian-Journal-of-Forest-Research 13(3): 384-389.
Keywords: fertilization
thinning
tree morphology
tree physiology
Abstract: A
24-yr-old stand in
24. Brix, H. and A.K. Mitchell. 1986.
Thinning and nitrogen fertilization effects on soil and tree water stress in a
Douglas-fir stand. Canadian-Journal-of-Forest-Research 16(6): 1334-1338.
Keywords: thinning
fertilization
soil properties
tree physiology
Abstract: Soil
and tree water potentials were studied for 10 yr in a Douglas fir stand near
Shawnigan Lake, British Columbia that was treated when 24 yr old with heavy
thinning (removing superscript 2/3 of b.a.) and/or fertilization with 448 kg
N/ha as urea. Control plots were not thinned or fertilized. Throughout the 10
yr, thinning increased soil water potential during the dry summer periods
(July-early Oct.) by as much as 1 MPa. The effect of fertilization on soil
water potential was slight and nonsignificant, and only apparent towards the
end of the study in spite of large increases in leaf area (50% after 7 yr).
Fertilization increased water use efficiency. The favourable soil water
conditions produced by thinning led to improved shoot water potential only during
predawn and early morning. Removal of understorey in a thinned and fertilized
plot did not affect soil or shoot water potential.
25. Carr, W.W. 1987. Restoring productivity on degraded forest soils: two case studies.
B.C. Ministry of Forests FRDA-Report 002. vi + 21 p.
Keywords: site preparation
fertilization
tree physiology
growth
soil properties
Abstract: The use
of green fallowing was studied at 2 sites, viz. (a) a coastal site at Koksilah,
15 km NW of Shawnigan Lake, British Columbia, where extensive subsoil exposure
had resulted from roading operations in a highly productive Douglas fir
(Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) stand, and (b)
an inland site 30 km S. of Vanderhook including several landings and skid roads
which had been deep-ripped to a depth of 50 cm, reducing soil density to 1350
kg/msuperscript 3. Plots at (a) were seeded in 1976 at 100 kg/ha with a
grass/legume mixture including 3 spp. of Trifolium and Lotus corniculatus, and
received NPK (
26. Carter, R. and K. Klinka. 1992.
Use of ecological site classification in the prediction of forest productivity
and response to fertilisation. South-African-Forestry-Journal (160): 19-23.
Keywords: fertilization
growth
soil properties
Abstract: The
results are presented of two related studies in southern coastal
27. Carter, R. and R. Scagel. 1989.
The effects of stand density and fertilization on stand development in immature
coastal Douglas-fir. B.C. Ministry of Forests FRDA-Report
094. i + 15 p.
Keywords: fertilization
thinning
growth
tree morphology
Abstract: The effects
of urea fertilizer were studied in Pseudotsuga menziesii stands spaced to 500,
750 and 1000 stems/ha in coastal
28. Carter, R.E. and R.P. Brockley.
1990. Boron deficiencies in
Keywords: fertilization
growth
tree/stand health
Abstract: Two
case-studies are presented, outlining methods of
diagnosis and treatment evaluation of boron deficiencies in a Douglas fir
(Pseudotsuga menziesii) stand in coastal southern
29. Carter, R.E., E.R.G. McWilliams
and K. Klinka. 1998. Predicting response of coastal Douglas-fir to fertilizer
treatments. Forest-Ecology-and-Management 107(1/3): 275-289.
Keywords: fertilization
growth
soil properties
Abstract: A
broadly-based, intensive Douglas-fir (Pseudotsuga menziesii) fertilizer
experiment throughout southern coastal
30. Chapman, R.J. 1984. Growth, nitrogen content and water relations of sludge-treated
Douglas-fir seedlings. Forestry-Abstracts 45(7): 385-386.
Keywords: fertilization
growth
tree physiology
OSU
Link
Non-OSU
Link
31. Chappell, H.N., D.W. Cole, S.P.
Gessel and R.B. Walker. 1991. Forest fertilization research and practice in the
Keywords: fertilization
soil properties
Abstract: A
review showed that most
32. Chappell, H.N., C.E. Prescott and
L. Vesterdal. 1999. Long-term effects of nitrogen fertilization on nitrogen
availability in coastal Douglas-fir forest floors.
Soil-Science-Society-of-America-Journal 63(5): 1448-1454.
Keywords: fertilization
soil properties
Abstract: The aim
of this study was to determine if N availability was elevated 8 to 12 years
after repeated N fertilization, and if the effects of N fertilization were
related to the soil N capital. Rates of N cycling in control and fertilized
plots of Douglas-fir (Pseudotsuga menziesii) in
33. Cochran, P.H., W. Lopushinsky and
P.D. McColley. 1986. Effect of operational fertilization on foliar nutrient
content and growth of young Douglas-fir and Pacific silver fir. Pacific-Northwest-Research-Station,-USDA-
Keywords: fertilization
tree physiology
growth
Abstract: During
1979-80, sulfated urea (pelletted) was applied to conifer stands in the
34. Cole, D.W., M.L. Rinehart, D.G.
Briggs, C.L. Henry and F. Mecifi. 1984. Response of Douglas fir to sludge
application: volume growth and specific gravity. In Proceedings of the
Technical Association of the Pulp and Paper Industry 1984 Research and
Development Conference, Appleton, Wisconsin, September 30-October 3. pp. 77-84.
Keywords: fertilization
thinning
growth
wood quality
Abstract: In 1977
and 1980 municipal sludge was applied to a 60-yr-old lowland Douglas fir stand
in
35. Colinas, C., R. Molina, J. Trappe
and D. Perry. 1994a. Ectomycorrhizas and rhizosphere
microorganisms of seedlings of Pseudotsuga menziesii (Mirb.) Franco
planted on a degraded site and inoculated with forest soils pretreated with
selective biocides. New-Phytologist 127(3): 529-537.
Keywords: planting operations
fertilization
soil properties
mycorrhizal response
Abstract:
Inoculation of planting holes with small amounts of soil from a mature forest
or a plantation can improve formation of ectomycorrhizas on Pseudotsuga
menziesii seedlings in degraded clearcuts in southwestern
36. Colinas, C., D. Perry, R. Molina
and M. Amaranthus. 1994b. Survival and growth of Pseudotsuga menziesii
seedlings inoculated with biocide-treated soils at planting in a degraded
clearcut. Canadian-Journal-of-Forest-Research 24(8): 1741-1749.
Keywords: planting operations
fertilization
growth
tree/stand health
tree morphology
Abstract: To
determine the factors of transfer soils responsible for increased seedling
survival and growth, planting holes, at a site in SW Oregon, were inoculated
with forest, plantation, and clear-cut soils subjected to one of 8 treatments:
(i) treated with fertilizer to test for effects of nutrients; treated with
biocides to test for effects of (ii) grazers (microarthropods or nematodes),
(iii) protozoa, (iv) fungi, or (v) bacteria; (vi) pasteurized; (vii)
Tyndallized; or (viii) untreated. Douglas fir (Pseudotsuga menziesii) seedlings
were planted in June 1990 and seedling growth and survival was assessed in
December 1990. Survival was increased by inoculation with untreated plantation
soils, but not if they were fertilized or treated with dimethoate + carbofuran
(grazercide), fumagillin (protozoacide), or oxytetracycline + penicillin
(bactericide). Addition of untreated forest soil did not increase survival. For
all soils, survival was increased by captan (fungicide), pasteurization and
Tyndallization. Untreated plantation and forest soil transfers increased dry
weights whereas neither did when treated with dimethoate + carbofuran. Dry
weights of seedlings given clear-cut soil were increased by fertilization,
pasteurization and Tyndallization of the soil; the latter two treatments also
increased the number of short roots. It is hypothesized that stimulation of
seedling growth by soil transfers was related to an increased rate of nutrient
mineralization due to microbivorous soil animals contained within the transfer
soils. Soil transfers may have enhanced seedling survival by at least two
mechanisms: (i) by providing a safe site for beneficial rhizosphere organisms
to proliferate, free from competing organisms that have proliferated in the
clear-cut soil; and (ii) through volatile organic compounds, especially
ethylene, that stimulated seedling root growth.
37. Crouch, G.L. and M.A. Radwan.
1981. Effects of nitrogen and phosphorus fertilizers on deer browsing and
growth of young Douglas-fir. Pacific-Northwest-Forest-and-Range-Experiment-Station,-USDA-
Keywords: fertilization
tree/stand health
growth
tree physiology
Abstract: N and P
fertilizers were applied in March 1968 singly or in combination at a rate
equivalent to 200 lb/acre of N or P to young trees (2-5 ft tall) in
38. 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.
OSU Link
Non-OSU Link
39. Dangerfield, J.
and H. Brix. 1981. Comparative effects of ammonium