1.
1987. Impact of intensive forestry practices on net stand values in British
Columbia. B.C.
Ministry of Forests FRDA-Report 014. 109 p.
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.
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2. Anderson, H.W. and M. Hyatt. 1981. Feasibility of hand application
of urea to forest land in western Washington.
In Proceedings: Forest Fertilization Conference,
University
of Washington,
Seattle,
Washington, USA.
Eds. S.P. Gessel, R.M. Kenady and W.A. Atkinson. pp.
205-208.
Keywords: fertilization
economics
Abstract: A large
scale pilot study to determine the potential of hand fertilizing forest stands
in western Washington
was undertaken by the Department of Natural Resources in 1976. Tests were
conducted in two major stand types of Douglas-fir (juvenile stands with voids
and openings and older open growh stands), where two hand spreading techniques
(broadcast and individual tree fertilization) and two types of work crews
(contract and DNR) were evaluated. During the study manhours of the various
job-related activities were recorded and costs determined. A total of 634 acres
was treated and costs ranged from $36.95 to $125.42 per acre and averaged
$81.74 per acre (1976 dollars). Costs varied because of stand type which
influenced the fertilizer rate and crew type which influenced the application
cost. Based on units treated in this study and assuming similar conditions,
estimates of hand fertilization costs for an operational fertilization project
where stand conditions would allow for a reduced fertilizer rate (individual
tree fertilization) would be approximately $52 per acre at the rate of 330
pounds of urea and $42 per acre at the rate of 220 pounds of urea. This
compares to costs of $61 per acre for hand broadcast application at 440 pounds
of urea and $56 per acre for aerial application at the same rate. Therefore,
where stand conditions allow for a reduced rate of fertilizer, hand application
could be a more inviting alternative to the normal procedure of aerial
application.
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3. Atkinson, W.A. 1981. Preliminary guidelines for fertilizing less than fully stocked
stands and mixed species stands. In Conference Proceedings: Forest
Fertilization Conference, University
of Washington,
Seattle,
Washington, USA.
Eds. S.P. Gessel, R.M. Kenady and W.A. Atkinson. pp.
59-61.
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.
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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.
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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 Washington
and Oregon.
A preliminary test of the model and its calibration compared predicted
responses with estimates of actual response derived from some fertilizer trials
on Vancouver Island.
Soil drainage class and foliar analysis data may help in qualitatively
inferring whether the model's site quality function leads to overestimation of
response. Future development of the model may include development and
calibration of a predictively better site quality function which quantitatively
uses site water regime and stand nutrient data.
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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 British
Columbia.
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7. Barclay, H., H. Brix and C.R.
Layton. 1982. Fertilization and thinning effects on a Douglas-fir ecosystem at Shawnigan
Lake:
9 year growth response. Pacific-Forestry-Centre,
Canadian-Forest-Service Information-Report BC-X-238. 35
p.
Keywords: fertilization
thinning
growth
Abstract: Further
results are given for a trial established in 1970 in a 24-yr-old stand in British
Columbia, last measured 6 yr
after treatment. Volume increments over 9 yr for heavy thinning alone, heavy
fertilizer (urea) treatment alone, or both together, were 46%, 75% and 120%,
respectively.
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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., British Columbia.
Ammonium nitrate yielded higher growth of diam. and vol. than urea over a 9-yr
period, particularly with thinning. Ht. growth was not affected by nitrogen
source. The efficiency of nitrogen fertilizing in terms of stem vol. response
per kilogram of nitrogen applied was greatest with ammonium nitrate in thinned
plots. Tree mortality increased substantially with fertilizing for both
sources, and decreased markedly with thinning.
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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.
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10. Barclay, H.J. and H. Brix. 1985b.
Fertilization and thinning effects on a Douglas-fir ecosystem at Shawnigan
Lake:
12-year growth response. Pacific-Forestry-Centre,
Canadian-Forest-Service Information-Report BC-X-271. 34
p.
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 British Columbia.
Fertilizers (urea) and thinning both increased vol. increments over 12 yr.
Refertilization 9 yr after initial treatment has produced substantial increases
in vol. increment.
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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.
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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 Douglas
firs at Shawnigan
Lake
(British
Columbia) were destructively
sampled. Dry wt. of seven aboveground components (wood, bark, dead branches,
new or old foliage, new twigs and live branches) were determined and regression
equations from d.b.h. were developed. Differences among treatments were shown
for all biomass components and for the proportion of the total biomass
allocated to each component. Thinning reduced the proportion of wood, bark and
dead branches while increasing the proportion of foliage and live branches.
Fertilization increased the proportion of branches but had negligible effects
on the proportions of other components.
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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 British
Columbia, Canada,
which had been treated with 3 levels of thinning and 3 levels of fertilizer 28
years previously. The 4 treatment extremes (no thinning or fertilizing, no
thinning and heavy fertilizing (448 kg N/ha as urea), heavy thinning (to 1/3
basal area) and no fertilizing, and heavy thinning and heavy fertilizing) were
sampled for foliage. Projected leaf areas were calculated from these biomass
samples using specific leaf areas derived in a previous biomass sampling. Total
one-sided leaf area was then computed by dividing the projected leaf areas by
0.9 to allow for lateral leaf curvature. In addition, LAI-2000 readings were
taken in the same plots and then factors were derived to convert LAI-2000
readings to total one-sided LAI. These conversion factors were found to vary
strongly with quadratic mean diameter, stand density, mean diameter at breast
height, mean height and stand basal area. The effect of live crown height was
minimal. These should allow the prediction of the conversion factor based on 2
or 3 of these highly correlated factors.
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14. Bare, B.B. 1981. Tax effects of
fertilization. In Proceedings: Forest
Fertilization Conference, University
of Washington,
Seattle,
Washington, USA.
Eds. S.P. Gessel, R.M. Kenady and W.A. Atkinson. pp.
238-242.
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 USA.
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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 Washington
State
were examined for repsonses in stem growth, leaf area, and stem growth per unit
leaf area. Although measurements occurred 20-30 yr after plot installation,
substantial effects from the various treatments were still present. Thinning
reduced leaf area of the stands but increased stem growth per unit leaf area,
resulting in little difference in stem growth per ha over the 5-yr measurement
period (1977-81). Fertilization increased both stand leaf area and stem growth
per unit leaf area, and more than doubled 5-yr stem growth per ha.
Consideration of the role of leaf area and stem growth per unit leaf area in
determining stand treatment responses may account for much of the variation
found among replicates of treatments or between studies on different sites.
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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.
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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.
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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.
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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
Sweet Home, Oregon, and a 48-yr-old
thinned stand near Corvallis.
Wood properties, studied between and within treatments, included ring density
(analysed by X-ray densitometry), earlywood and latewood density, min.
earlywood density, max. latewood density, and ring
width. There was n.s.d. in av. wood density between treatments. There were
significant between-treatment differences in MOE and MOR.
Heavy thinning (during the juvenile wood formation phase) reduced latewood
fibre length by 26.5%. Min. earlywood density and max.
latewood density were the most important components of
ring density.
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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. Seattle, Washington, USA:
University
of Washington
Press. pp. 246-257.
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.
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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.
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22. Brix, H. 1993. Fertilization and
thinning effect on a Douglas-fir ecosystem at Shawnigan
Lake:
a synthesis of project results. B.C. Ministry of Forests
FRDA-Report 196. X + 64 p.
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.
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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 British
Columbia was treated in
1971-72 with various intensities and combinations of N fertilization and
thinning. For 5-9 yr after treatments, trees were sampled to determine effects
on foliage quantity and sapwood characteristics at varying stem ht. together
with their relationships. Sapwood width remained relatively constant up the
stem where heartwood was present, but the number of annual rings it contained
decreased with ht. The sapwood width at b.h. increased with stem diam.;
treatments had little effect on % sapwood at b.h. The ratio of foliage mass to
sapwood cross-sectional area changed for different portions of the crown and
was lower when based on sapwood area at b.h. than at base of live crown.
Significant linear relationships of foliage mass and area to sapwood area at
b.h. were found, but relationships of foliage to b.a.
were just as close for all treatments; treatments significantly affected these
relationships with control trees having the lowest regression slopes.
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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.
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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 (10:30:10) at
450 kg/ha. Site nutrient levels improved substantially over 5 yr with N showing
the greatest gains, and Douglas fir seedlings (1+2) planted in 1977 responded
with increased foliar N and K contents and 300% greater ht. growth. Plots at
(b) were seeded in 1981 at 40 kg/ha with a legume mixture of 3 spp. of
Trifolium, Medicago sativa and L. corniculatus, and received NPK (19:19:19)
at 300 kg/ha. Nutrient gains were found after 2 yr for P, K and especially N,
and although foliar nutrient contents and growth of lodgepole pine (Pinus
contorta) seedlings showed no increase, the enhancement of site nutrient
capital is considered to be a gain likely to benefit commercial forestry
production.
OSU Link
Non-OSU
Link
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 British
Columbia. A total of 149
study plots in even-aged immature Douglas fir (Pseudotsuga menziesii) stands
were categorized into 6 ecologically similar site associations (indicated best
by climax plant communities) and into 15 soil moisture and soil nutrient
combinations, for the prediction of site index. Fifty-one of these plots were
used to predict basal area growth response to nitrogen fertilizer (225 kg N/ha
as urea). Regression models indicated strong correlations between Douglas fir
site index (m (height)/50 yr) and both indirect and direct measures of soil
moisture and nutrient regimes (Rsuperscript 2 >0.72; p <0.01). Third-year
basal area response to N fertilizer varied significantly among site
associations (Rsuperscript 2 = 0.60; p <0.01). Site index also showed a
significant relation with third-year basal area response (Rsuperscript 2 =
0.52; p <0.01), while the best predictive model included site associations
and pretreatment foliar N and sulfate-S (Rsuperscript 2 = 0.64; p <0.01). It
is suggested that the approach and methods of the study are applicable to
predicting site-specific growth performance and response to fertilization of
other tree species, including eucalypts.
OSU
Link
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Link
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 British
Columbia.
OSU Link
Non-OSU
Link
28. Carter, R.E. and R.P. Brockley.
1990. Boron deficiencies in British
Columbia: diagnosis and
treatment evaluation. Forest-Ecology-and-Management 37(1-3): 83-94.
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 British
Columbia and a lodgepole pine (Pinus
contorta) stand near Burns
Lake,
in the interior of the province. Site conditions commonly associated with B
deficiency are outlined, and relations between dormant-season foliar B
concentration and growing-season precipitation and moisture stress are
suggested. Diagnostic methods used in the study include examination of
deficiency symptoms, and foliar-analysis techniques; evaluation of response for
corrective fertilizer treatments is based on changes in frequency and severity
of deficiency symptoms and growth responses, measured by graphical-analysis and
changes in shoot length between treatments. Boron deficiencies and response to
B fertilizers are difficult to confirm. Results of graphical-analysis and
examination of frequency and severity of deficiency symptoms were inconclusive,
while changes in shoot length identified a measurable response in the Burns
Lake
fertilizer trial with lodgepole pine. Deficiencies appear to be acute rather
than chronic, and may not occur in untreated control trees for several years
after establishment of fertilizer trials. Alternative causes for deficiency
symptoms are also common, further complicating diagnosis and evaluation of
response to treatment. It is concluded that all future trials should include
nitrogen and/or other limiting nutrients with and without B to aid in
identification of acute B deficiencies and deficiencies induced by increasing
growth.
OSU
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Link
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 British
Columbia (48 sites) was used
to examine 3- and 6-yr crop tree growth responses to prescribed fertilizer
applications (N alone, and N + additional nutrients identified as potentially
deficient by foliar analysis). Absolute and relative basal area responses were
evaluated in relation to site associations of the provincial ecosystem
classification system, site index (SI), and a large number of site and stand
chemical and physical properties. Few of the site and stand variables examined
as possible response prediction criteria appeared to have any real utility. The
strongest relationships found were between relative basal area response and (1)
site index (Rsuperscript 2 0.46 for both 3- and 6-yr responses), (2) mineral
soil mineralizable-N (Rsuperscript 2 0.50 and 0.46 for yr 3 and 6 responses, respectively),
and (3) total mineralizable-N (Rsuperscript 2 0.47 and 0.50 for yr 3 and 6
responses, respectively). In all cases average relative response declined with
increasing site quality. However, there were highly productive sites (SI50
<more or =>35 m) characterized by an absence of growing-season water
deficits and relatively low foliar N concentrations (12-13 g/kg) which showed
significant fertilizer responses. These sites are where the greatest financial
returns from fertilizing may be realized. Relationships identified between site
and stand variables and basal area responses were, in many cases, different
from those found by other researchers for coastal Douglas fir. This brings the
portability of identified relationships into question.
OSU
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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
Pacific Northwest.
Fertilizer-Research 27(1): 129-140.
Keywords: fertilization
soil properties
Abstract: A
review showed that most Pacific Northwest USA
Douglas-fir (Pseudotsuga menziesii) forest sites are nitrogen deficient.
Mineral cycling research has shown high C:N ratios and
low nitrification rates for soils in the region. Research and development
projects in the Pacific Northwest
have produced an information base that is used to select sites and stands for
fertilization and to forecast growth after treatment. Much of the basis for
operational fertilization programmes in western Oregon
and Washington
comes from cooperative research; current activities for these programmes are
directed toward improving site-specific response information. Forest
fertilization in the Pacific Northwest
has become a major silvicultural practice over the past two decades. Forest
industry and government organizations managing forest lands in western Oregon
and Washington
apply nitrogen fertilizer to Douglas-fir stands over a range of soil and stand
types. About 50 000 to 55 000 ha are fertilized each year, and future
programmes will probably be of similar magnitude. Most current plans for
management regimes including fertilization require multiple applications.
OSU Link
Non-OSU
Link
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 Oregon,
USA,
were compared by measuring net N mineralization rates in forest floors and by
estimating rates of N turnover from the litterfall/forest floor ratio.
Litterfall N contents, litter N concentrations, and rates of N turnover
increased along the gradient in soil N capital in both control and fertilized
stands. Fertilization did not affect litterfall N content, but C:N ratios of litter and forest floors were significantly
lower in fertilized stands along the gradient. Turnover rates of N in the
forest floors were not higher in fertilized plots than in control plots, nor
were rates of net N mineralization affected by fertilization. Net nitrification
rates were higher in some of the plots that received 1120 kg N ha-1 than in
control plots. Nitrogen fertilization did not result in a sustained increase in
N cycling and N availability analogous to a higher site N capital, and the
effect of N fertilization was not related to the initial soil N capital of
these sites.
OSU
Link
Non-OSU
Link
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-Forest-Service
Research-Note PNW-RN-445. 10 p.
Keywords: fertilization
tree physiology
growth
Abstract: During
1979-80, sulfated urea (pelletted) was applied to conifer stands in the Wenatchee
National Forest,
west of Cle
Elum, Washington.
Nitrogen concn. in current needles of Pacific silver
fir (Abies amabilis) showed a significant 1.9-fold increase after fertilizer
treatment compared with a non-significant 1.3-fold increase in Douglas fir
(Pseudotsuga menziesii). A significant 2.5-fold increase in foliar N also
occurred in bracken (Pteridium aquilinum). Analysis of foliage from untreated
trees indicated N deficiency in A. amabilis, but N concn. in
Douglas fir was above threshold values. Fertilizer treatment did not affect
foliar S in either species, but increased needle surface area for A. amabilis.
Tree diam. growth, stand b.a. growth and vol. growth
were all increased by fertilizer treatment.
OSU
Link
Non-OSU Link
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 Washington
State.
Application procedures and rates and suitable sites for treatment are
described. There was a 6 yr av. diam. growth response of 93% in unthinned and
48% in thinned stands treated with 142 t/ha sludge and a vol. growth response
of 53 and 42%, respectively. The accelerated rate of growth has not shown signs
of decreasing since treatment. Relative density of sludge-grown wood was 10-15%
less than that of untreated wood, but within the range for Douglas fir grown on
higher land. This is thought to be a result of the change in forest site
produced by the sludge treatment.
OSU
Link
Non-OSU
Link
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 Oregon.
To determine the component(s) of transferred soil responsible for increased
ectomycorrhiza formation, soil from a clearcut, a mature forest and a
plantation was treated with one of the following: (1) fertilizer to test for
the effect of nutrients, (2) dimethoate and carbofuran to test for the effect
on microarthropods or nematodes, (3) fumagillin to test for the effect on
protozoa, (4) captan to test for the effect on fungi, (5) penicillin and
oxytetracycline to test for the effect on bacteria, (6) pasteurization to test
for the effect of active forms of organisms, (7) Tyndallization to test for the
effect of resting forms of organisms, or (8) water as a control. The effect was
studied of inoculation with soil subjected to these treatments on number and
types of ectomycorrhizas, on length of active mycelium, and on number of active
bacteria in the rhizosphere. Inoculation with untreated forest or plantation
soils increased the number of ectomycorrhizas but did not change the
mycorrhizal types present. Most agents had different effects in different
soils. Inoculation with pasteurized and Tyndallized
clearcut and plantation soils increased the number of Rhizopogon- and
Thelephora-type ectomycorrhizas and decreased the number of active bacteria, as
did untreated forest soil. It is hypothesized that the role of the soil
transfer is to provide a rhizosphere environment free from a deleterious
organism present in the clearcut. In this environment, beneficial organisms
present in the clearcut or brought in with the seedling from the nursery can
proliferate.
OSU
Link
Non-OSU
Link
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.
OSU
Link
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Link
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-Forest-Service. Research-Note PNW-RN-368. 15 p.
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 Oregon
and Washington.
Trees were examined and measured for up to 4 yr. In the first year after
treatment trees given the N-only fertilizer in Washington were more heavily
browsed by black tailed deer (Odocoileus hemionus columbianus), but this effect
disappeared in the second year. Height growth was increased by N-only treatment
in taller trees in Oregon after 1 and 2 yr, but the effect had disappeared
after 4 yr. Total N content was significantly increased by the N and N + P
treatments in the first year, but this effect also disappeared after 2 yr. The
amounts of moisture, ash, Ca and P, and diam. growth were not affected by any
treatments.
OSU
Link
Non-OSU Link
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-Forest-Service
General-Technical-Report PNW-GTR-128. ii + 79
p.
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 nitrate and urea fertilizers
on tree growth and soil processes. In Proceedings: Forest
Fertilization Conference, University
of Washington,
Seattle,
Washington,
USA.
Eds. S.P. Gessel, R.M. Kenady and W.A. Atkinson.
pp. 133-139.
Keywords: fertilization
thinning
growth
tree physiology
Abstract: Growth
response of Douglas-fir to ammonium nitrate and urea, applied at rates of 200 and
400 pounds per acre (224 and 448 kilograms of nitrogen per hectare), was
studied over a 7-year period at Shawnigan Lake, B.C. Diameter growth was 21 and
9 percent better, respectively, for the two rates with ammonium nitrate than
with urea in unthinned plots and 7 percent better for plots that had been
thinned and received 400 pounds per acre (448 kilograms nitrogen per hectare).
Foliar nitrogen concentrations also increased most with ammonium nitrate
fertilzization during the first 2 years, indicating that nitrogen from this
source was initially more readily available to the trees. This is explained in
part by the greater mobility of nitrate supplied by ammonium nitrate and by
nitrogen immobilization in buildup of bacterial populations with urea.
OSU
Link
Non-OSU
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40. DeBell, D.S., C.A. Harrington and J.
Shumway. 2002. Thinning
shock and response to fertilizer less than expected in young Douglas-fir stand
at Wind
River Experimental
Forest.
Pacific-Northwest-Research-Station,-USDA-Forest-Service
Research-Paper PNW-RP-547. ii + 20 p.
Keywords: fertilization
thinning
precommercial thinning
growth
Abstract: Three
thinning treatments (thinned to 3.7 by 3.7 m, thinned to 4.3 by 4.3 m, and an
unthinned control treatment with nominal spacing averaging 2.6 by 2.6 m) were
installed in a 10-year-old Douglas-fir (Pseudotsuga menziesii) plantation
growing on a low-quality site at the Wind
River Experimental
Forest
in southwest Washington,
USA.
Two years after thinning, two fertilizer treatments were superimposed on the
design (0 and 224 kg per ha of nitrogen applied as ammonium nitrate). Diameter
growth increased with increasing spacing throughout the 6-year study period,
and it was also increased by fertilizer in both the thinned and unthinned (control)
treatments. Thinning shock, a reduction in height growth after thinning, was
expected at this study site because severe thinning shock had been documented
in earlier nearby trials. Height growth was initially reduced slightly by
thinning, but by the third 2-year period after thinning, height growth in
thinned, unfertilized treatments was equal to or greater than height growth in
the unthinned, unfertilized treatment. Fertilizer application increased height
growth on average by 13 per cent in the first 2 years after fertilizer
application. In the third and fourth years after fertilizer application,
however, fertilizer increased average height growth by 9 per cent, but the
increase was substantial (16 per cent) only in the unthinned control treatment.
The mild, ephemeral nature of thinning shock in our study was in contrast to
the severe, long-lasting shock in earlier studies at Wind
River. The milder shock in our study could be related
to one or more of the following: (1) thinning was done at an early age, (2)
impacts of fire (natural or prescribed) preceding planting were minor, and (3)
seed source of the planted stock was appropriate for the location. Based on
comparisons with other studies at Wind
River and elsewhere, we suspect that use of nonlocal,
maladapted seed sources in the earlier studies may have predisposed those trees
to thinning shock. Furthermore, we suspect that the much higher responses to
fertilizer application reported in the earlier studies may be associated with
intense natural fires prior to planting, and the reduced nutritional status of
those sites may have been further exacerbated by the use of maladapted seed
sources.
OSU
Link
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41. DeBell, D.S., R.R.
Silen, M.A. Radwan and N.L. Mandel. 1986. Effect of family and nitrogen fertilizer on growth
and foliar nutrients of Douglas-fir saplings. Forest-Science 32(3): 643-652.
Keywords: fertilization
growth
tree physiology
Abstract: Urea
(224 kg N/ha) was applied to 12-yr-old Douglas fir of 12 open-pollinated
families growing near Corvallis,
Oregon.
Ht. and d.b.h. were measured before fertilization in Feb. 1979 and 4 growing
seasons later, and tree vol. were estimated. Vol. increment varied among
families, but was increased by an av. 7% by fertilizer. Concentrations of
foliar nutrients, analysed in winter 1979 and 1980, differed significantly
between families and in response to fertilization. The familyxfertilizer
interaction was not significant for any growth or foliar nutrient measured.
OSU
Link
Non-OSU Link
42. Dosskey, M.G., L. Boersma and
R.G. Linderman. 1993. Effect of phosphorus fertilization on water stress in
Douglas fir seedlings during soil drying. Plant-and-Soil 150(1): 33-39.
Keywords: fertilization
tree/stand protection
growth
tree physiology
photosynthesis
Abstract: A
growth chamber experiment was conducted to determine if P fertilizing to
enhance the P nutrition of otherwise N and P deficient Douglas fir (Pseudotsuga
menziesii) seedlings reduces water stress in the seedlings during drought
periods. Seedlings were grown in pasteurized mineral soil under well watered
conditions and fertilized periodically with a small amount of nutrient solution
containing P at three levels: 0, 20, or 50 mg/litre. By age 6 months, leaf
nutrient analysis indicated that N and P were deficient in control (0 mg
P/litre) seedlings. The highest level of P fertilizer, which doubled leaf P
concentration, did not affect plant biomass, suggesting that N deficiency was
limiting growth. When these seedlings were subjected to drought, there was no
effect of P fertilizing on leaf water potential or osmotic potential.
Furthermore, P fertilized seedlings had lower stomatal conductance and net
photosynthesis rate. These results indicate that enhanced P nutrition, in the
presence of N deficiency, does not reduce water stress in Douglas fir seedlings
during drought periods.
OSU
Link
Non-OSU Link
43. Driessche, R.v.-d. 1988b. Response of Douglas-fir (Pseudotsuga menziesii (Mirb.)
Franco) to some different fertilizers applied at planting. New-Forests 2(2):
89-110.
Keywords: nursery operations
nursery fertilization
fertilization
growth
tree/stand health
tree physiology
Abstract: Four
fertilizer experiments to assess type of fertilizer, dosage and timing, were
conducted on eastern Vancouver
Island, BC,
Canada.
Two-yr-old, bare root planting stock was used except in experiment 3, where
container stock was compared with bare root stock. Little growth response was
obtained after one year, but height growth responses of 12 to 31% were measured
after 3 to 6 yr with fertilizers supplying 8.4 to 16.8 g N per tree. Growth
responses were little affected by type of fertilizer and were primarily due to
N, with release rate having no marked effect. The exception to this was triple
superphosphate which did not increase growth but did increase survival.
Survival was reduced by ammonium sulphate and to a lesser extent by Agriform
(NPK). Container seedlings responded more to fertilization at planting than
bare root seedlings. Seedling N, P and K concn. and contents declined following planting for 6 months and
only started to recover after July. Application of fertilizer caused a small
increase in seedling nutrient concn. regardless of
date, but this had no detectable effect on dry weight measured 6 wk later.
OSU
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44. Duke, K.M., G.M. Townsend and
W.A. White. 1989. An economic analysis of fertilization and thinning effects on
Douglas-fir stands at Shawnigan
Lake.
Canadian-Forest-Service, Pacific and Yukon
Region Information-Report BC-X-312. v + 19 p.
Keywords: fertilization
thinning
economics
computer modeling
Abstract: A
single-tree density-dependent growth model was used to project, from age 24 to
age 120 yr, 9 combinations of thinning and fertilizer application (nitrogen as
urea or ammonium nitrate) in Douglas fir (Pseudotsuga menziesii) near Shawnigan
Lake, British Columbia. Costs and benefits were estimated as a function of
stand diameter, and forestry investment criteria were used to evaluate each
treatment on both an incremental and a regime basis. The effect of rising real prices, and the treatment of silvicultural costs as an
initial investment or as a harvest cost were also studied.
OSU Link
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Link
45. Edmonds,
R.L. and T. Hsiang. 1987.
Forest
floor and soil influence on response of Douglas-fir to urea.
Soil-Science-Society-of-America-Journal 51(5): 1332-1337.
Keywords: fertilization
thinning
growth
soil properties
Abstract: Data
from the Regional Forest Nutrition Research Project (RFNRP) in Washington
and Oregon
were analyzed to improve stand-specific prediction of Douglas-fir [Pseudotsuga
menziesii (Mirb.) Franco] response to urea fertilization.
The response variable (relative difference in volume growth between fertilized
and control plots 4 yr after fertilization with 448 kg N/ha) was regressed
against 28 stand and site variables (e.g., age, elevation, forest floor C/N
ratio, soil cation exchange capacity, etc.) using stepwise multiple regression
analysis. Data from 120 installations were stratified by thinning level
(thinned or unthinned), geographic location (provinces), and site quality (site
index and class). Forest
floor C/N ratio was the dominant variable related to response. In thinned installations
of high site quality (site classes 1 and 2), 60% of variation in response was
explained by the forest floor C/N, and 75% of the variation in response was
explained with inclusion of surface soil exchangeable K. In thinned, low site
quality stands, response was not as well related to forest floor C/N. Analysis
of the data by province indicated that S may be limiting in southwest Oregon
and P in coastal Washington.
OSU
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46. Entry, J.A., K. Cromack, Jr.,
R.G. Kelsey and N.E. Martin. 1991. Response of Douglas-fir to infection by
Armillaria ostoyae after thinning or thinning plus fertilization.
Phytopathology 81(6): 682-689.
Keywords: thinning
fertilization
tree/stand protection
growth
tree morphology
carbon allocation
tree/stand health
tree physiology
Abstract: Second-growth
stands of Douglas-fir (Pseudotsuga menziesii) were thinned to a 5- x 5-m
spacing (TT); additional plots were thinned and fertilized once with 360 kg of
N (as urea)/ha (TF). An unthinned, unfertilized stand (UT) served as a control.
Ten years after treatment, trees were inoculated with 2 isolates of A. ostoyae.
Trees receiving the TF and TT treatments produced greater diameter growth, leaf
area, and wood production/msuperscript 2 leaf area per year than did those
under the UT treatment. Rates of infection by A. ostoyae were highest in trees
that received the TF and lowest in trees that received the TT treatment. Concn
of sugar, starch and cellulose in root bark tissue were highest in trees
receiving the TF treatment and lowest in trees receiving TT treatment. Concn of
lignin, phenolics and protein-precipitable tannins were highest in root bark
from TT trees and lowest in root bark from TF trees. Biochemical parameters of
root bark tissue were regressed with incidence of infection; coefficients of
determination (rsuperscript 2) ranged from 0.07 (starch) to 0.57 (phenolic
compounds). Ratios of the energetic costs of phenolic and of lignin degradation
to the energy available from sugars (Epd:Eas and
Eld:Eas) were correlated with incidence of infection (rsuperscript 2 = 0.77 and
0.70, respectively). It is concluded that thinning combined with fertilization
may predispose P. menziesii trees to infection by A. ostoyae by lowering concn
of defensive compounds in root bark and increasing the energy available to the
fungus to degrade them.
OSU
Link
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Link
47. Feller, M.C., J.P. Kimmins and
K.A. Scoullar. 1983. FORCYTE-10: calibration data and simulation of potential
long-term effects of intensive forest management on site productivity, economic
performance, and energy benefit/cost ratio. In I.U.F.R.B.
Symposium on. Forest Site and
Continuous Productivity; Seattle,
Washington;
August 22-28, 1982.
Eds. R. Ballard and S.P. Gessel. Pacific-Northwest-Forest-and-Range-Experiment-Station,
USDA-Forest-Service General-Technical-Report PNW-GTR-163 Part B. 179-200 pp.
Keywords: thinning
fertilization
soil properties
economics
computer modeling
Abstract: FORCYTE
(FORest
nutrient Cycling and Yield Trend Evaluator) is a computer simulation model of
forest plant biomass production, litterfall, and decomposition, complete with
nutrient cycling, nutrient limitation on growth, and a variety of management
interventions. The model is a computerized approach to the estimation of the
effects of varying thinning and fertilizer regimes, utilization level, and
rotation length on site nutrient budgets, stand productivity, and the economic
performance and energy efficiency of management. The model has evolved over 5
years to its present version FORCYTE-10, which is briefly described.
Accompanying the development of FORCYTE, there has been a series of field
research projects. Detailed biomass and biogeochemical descriptions of age
sequences of Douglas-fir stands on both good and poor sites have been prepared
for purposes of model calibration and testing. The present report summarizes
some of the results of the FORCYTE-10 field studies on Vancouver Island,
British Columbia,
and presents some examples of the use of the model when calibrated with these
data.
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48. 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-Forest-Service
Research-Paper PNW-RP-390. ii + 17 p.
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 Oregon
and western Washington.
Data from a recent study of grade recovery from pruned logs were analysed and a
spreadsheet program was developed and used to simulate the increase in grade
recovery and financial returns from pruning. Results are presented for a range
of site indices, ages at time of pruning and time of harvest, product prices
and interest rates, and for stands with and without nitrogen fertilizer
treatment. Results showed that a 5-yr difference in the time of pruning can
make a substantial difference in the financial return. An earlier age at
pruning always gave a higher return. At 4 and 8% interest rates, the return was
generally greatest when the harvest was 40-50 yr or 30-40 yr, respectively,
after pruning. Fertilizer treatment substantially increased the return from
pruning, especially on poor sites.
OSU
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49. Fight, R.D., J.M. Cahill, T.D.
Fahey and T.A. Snellgrove. 1988. A new look at pruning coast Douglas-fir.
Western-Journal-of-Applied-Forestry 3(2): 46-48.
Keywords: pruning
thinning
fertilization
economics
Abstract: A short
account of an evaluation of the financial returns of pruning coast Douglas fir
(Pseudotsuga menziesii), using new product-recovery information and computer
software, and assuming that: the analysis is for lumber, interest rates are 4
and 8%, stands are fertilized 2 or 3 times and thinned periodically, and that
trees were pruned at age 20 yr. Results showed that higher returns from pruning
could be achieved by concentrating pruning in younger stands that have a higher
site index and that will be fertilized.
OSU
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50. Fox, T.R. 2004. Nitrogen
mineralization following fertilization of Douglas-fir forests with urea in Western Washington.
Soil-Science-Society-of-America-Journal 68(5): 1720-1728.
Keywords: fertilization
soil properties
Abstract: Nitrogen
mineralization following repeated applications of urea fertilizer was
determined in the A horizon soil from two stands of Douglas-fir [Pseudotsuga
menziesii (Mirb.) Franco] in the Cascade Mountains of Washington.
Repeated applications of urea at rates ranging from 0 to 600 kg N ha-1 were
made at annual and 5-yr intervals over a 6-yr period. Nitrogen fertilization
increased N mineralization potential in these soils. However, soil N
mineralization followed a quadratic relationship with the total amount of N
applied in fertilizer over the 6-yr treatment period, increasing up to total
application rates of 450 kg N ha-1 and then declining at higher rates. The
decrease in N mineralization rates at the high N fertilization rates may be due
to changes in the quality of soil organic matter, which reduced the
effectiveness of extracellular enzymes and decreases the rate of decomposition
and mineralization. Soil pH dropped following urea fertilization, with greater
declines observed in the highest rates of urea fertilizer. Decreases in
extractable Ca and Mg levels in the soil accompanied the decline in soil pH.
These results suggest that high rates of nitrification occurred and that
nitrate leaching was stripping Ca and Mg from the cation-exchange complex in these
soils. It appears that repeated applications of urea fertilizer at low to
intermediate rates may increase long-term N availability and thus improve soil
quality. However, annual applications of high rates of urea may decrease soil
quality because under these circumstances N mineralization did not increase and
there was a loss of cations from the soil.
OSU
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51. Gardner, E.R. 1990. Fertilization and thinning effects on a
Douglas-fir ecosystem at Shawnigan
Lake:
15-year growth response. Canadian-Forest-Service, Pacific and
Yukon
Region Information-Report BC-X-319. ix + 42 p.
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 British Columbia,
were analysed on the basis of per hectare, individual tree, crop tree and tree
size class. Thinned and unthinned plots were measured.
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52. Gartner, B.L., J.J. Morrell, C.M.
Freitag and R. Spicer. 1999. Heartwood decay resistance by vertical and radial
position in Douglas-fir trees from a young stand. Canadian-Journal-of-Forest-Research
29(12): 1993-1996.
Keywords: fertilization
thinning
wood quality
Abstract:
Heartwood durability of Douglas-fir (Pseudotsuga menziesii var. menziesii) was
studied as a function of vertical and radial position in boles of trees with a
wide range of leaf area/sapwood area ratios. Six 34-year-old trees were
harvested from each of three plots: very dense, thinned, and thinned and
fertilized with N, P, K, Ca, S and Fe (51, 11, 10, 7, 4 and 0.3 kg/ha,
respectively), established 14 years before at a site in the central Cascades of
Oregon. Heartwood samples from three radial positions and five heights were
incubated with the decay fungus Postia placenta [Oligoporus placenta]. There
were no significant differences in wood mass loss (decay resistance) by
vertical or radial position. One could expect that trees with high leaf
area/sapwood area could have the carbon to produce heartwood that is more
resistant to decay than trees with lower leaf area/sapwood area. However, no
relationship was found between leaf area above node 20, sapwood area there, or
their ratio, and the decay resistance of outer heartwood at that node. These
results suggest that, for young Douglas-fir trees, heartwood durability does
not vary with position in the bole or with environments that alter the balance
of sapwood and leaf area in a tree. It is suggested that young stands may thus
be robust with respect to the effect of silvicultural regimes on heartwood
durability.
OSU
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53. Gertner, G.Z. 1984. Localizing a diameter increment model with a sequential Bayesian
procedure. Forest-Science 30(4): 851-864.
Keywords: fertilization
growth
Abstract: A procedure
is described for modifying a non-linear model taken from a regional forest
growth projection system for use in a smaller subregion. Diameter growth
monitored in the subregion of interest is used to adjust the parameters. The
amount of adjustment required depends on the precision of the growth estimates
from the regional model and of the estimates based on the local sample. More
weight is given to the local estimates when their precision is relatively high
in comparison with the regional estimates. An example is given of modifying a
model developed for the Western Oregon Region for a Douglas fir stand in NW
Oregon. In another example the procedure is used to adjust for the effects on
diam. increment of fertilizing with urea.
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54. Gessel, S.P. and W.A. Atkinson.
1984. Use of fertilizers in sustained productivity of Douglas-fir forests. In
Forest soils and treatment impacts: Proceedings, Sixth North American Forest
Soils Conference, Department of Forestry, Wildlife and Fisheries, University of
Tennessee, Knoxville, TN, June 1983. pp. 67-87.
Keywords: fertilization
growth
economics
Abstract: A
review is given of studies leading to the establishment of nitrogen deficiency
as a factor reducing growth and the development of N fertilization programmes.
Data from several long-term fertilizer trials in Washington
and Oregon
support the conclusion that N deficiency is frequently a controlling factor in
the growth of Douglas fir and that additions of N can result in long-term
growth increases. The economics of fertilization and the continued availability
of nitrogen fertilizers are discussed.
OSU Link
55. Gessel, S.P., R.E. Miller and
D.W. Cole. 1990. Relative importance of water and nutrients on the growth of
coast Douglas fir in the Pacific
Northwest. Forest-Ecology-and-Management 30(1-4):
327-340.
Keywords: fertilization
growth
soil properties
Abstract: The
Douglas-fir region in northwestern North
America is characterized by abundant moisture supply
during winter, extended dry periods during the growing season and significant
differences in water availability. Many soils have low fertility and indigenous
tree species respond to nitrogen fertilization, especially Douglas fir
(Pseudotsuga menziesii). Although irrigation of commercial forests in this
region is currently impractical, questions arising about the relative
importance of water and nutrients were examined using long-term growth data
from three studies. At Pack
Forest
(Washington),
fertilization without irrigation doubled growth rates, and no positive growth
responses were measured from irrigation. Short-term (5 yr) irrigation with
sewage effluent containing many nutrients resulted in a six-fold increase in
biomass production for poplar and three-fold for Douglas fir as compared to
irrigation with equal volumes of river water. Volume growth in 12- to 65-yr-old
stands in southwestern Oregon
was increased by fertilization at about 70% of the locations; annual gain
averaged 2.73 msuperscript 3/ha for 5-12 yr. Response was not related to annual
precipitation, which ranged from 81 to 279 cm, nor other moisture-related
variables. Absolute and relative volume response showed highest correlation
with soil carbon : nitrogen ratio. Compared with
nutrition, moisture does not seem to be a major limiting factor for growth in
the Douglas fir region of the Pacific
Northwest.
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56. Gessel, S.P., E.C. Steinbrenner
and R.E. Miller. 1981. Response of Northwest forests to elements other than
nitrogen. In Proceedings: Forest
Fertilization Conference, University
of Washington,
Seattle,
Washington,
USA.
Eds. S.P. Gessel, R.M. Kenady and W.A. Atkinson. pp.
140-149.
Keywords: fertilization
growth
economics
Abstract: This
paper reviews the development of forest tree nutrition research in the
Northwest. Field observations, foliar analysis, and greenhouse cultures using
both solution and forest soil as media established deficiency symptoms and
levels for major and minor elements. Field experimentation with the entire
range of essential elements has failed to demonstrate widespread deficiencies
of elements other than nitrogen. Certain test areas have shown somewhat better
response to combinations of elements; but because of the limitations of
experimental design and field variation, the response does not generally have a
high statistical significance. In some cases of apparent response, application
of fertilizer materials other than nitrogen does not appear to be economic.
There is sufficient evidence of response to other elements to suggest that much
work needs to be done. Increased utilization of forest materials, shorter
rotation, and greater yields with nitrogen fertilization all point to the fact
that many of the Northwest forest areas could have future elemental
deficiencies, other than nitrogen.
OSU
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57. Graff, J.E., Jr., R.K. Hermann
and J.B. Zaerr. 1999b. Ionic balance and organic acids in
western redcedar, western hemlock, and Douglas-fir seedlings grown in low- and
high-N soils. Canadian-Journal-of-Forest-Research 29(6): 669-678.
Keywords: fertilization
tree physiology
Abstract: Seedlings
of western redcedar (Thuja plicata), western hemlock (Tsuga heterophylla) and Douglas
fir (Pseudotsuga menziesii) were transplanted into soils collected in early May
1987 from 2 sites with low (near Carson, Washington) and high (near the Oregon
coast) levels of available NO3- (and total N). Current-year foliage was sampled
after 10 weeks to determine the effect of N availability on foliar cation-anion
balance (C-A) and the concentrations of low molecular weight organic acids of
the 3 species. Carboxylate concentrations were estimated by using the
difference between sums of cations and anions (C-A): 750 mequiv/kg for Thuja
plicata, 351 mequiv/kg for Tsuga heterophylla and 266
mequiv/kg for P. menziesii. Quinic acid was a primary constituent, accounting
for 40% of the total for Thuja plicata and 75% for Tsuga heterophylla and P.
menziesii. Oxalic acid was present in greatest concentration in the foliage of
Thuja plicata (65 mequiv/kg) but was a minor
constituent in both other species. The quantified acids accounted for only 15%
of the C-A of Thuja plicata but >80% of the C-A of the other species. It is
suggested that a considerable portion of the C-A balance not accounted for in
Thuja plicata may be associated with the accumulation of CaCO3 and that
litterfall deposition of CaCO3 may lead to the consumption of H+ ions and
enrichment of exchangeable soil Ca in the rooting zone of long-lived Thuja
plicata trees. No statistically significant differences between the soils were
detected with regard to C-A or the concentration of
organic acids.
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58. Green, R.N. and R.E. Carter.
1993. Boron and magnesium fertilization of a coastal Douglas-fir plantation.
Western-Journal-of-Applied-Forestry 8(2): 48-53.
Keywords: fertilization
growth
tree/stand health
tree physiology
Abstract: A study
was made of the role of boron and magnesium nutrition in the occurrence of
severe growth distortion symptoms in Douglas-fir (Pseudotsuga menziesii) in the
Skwawka
River
valley of south coastal British
Columbia. Four fertilizer
treatments, including boron (2.25 kg/ha B), magnesium (42 kg/ha Mg), boron plus
magnesium, and a control, were applied in conjunction with planting on a site
believed to be deficient in these nutrients. After 5 growing seasons, only
treatments containing boron (B and B + Mg) showed improved height growth
compared to controls. The incidence of leader dieback, swollen leading shoots,
and foliage distortion was significantly related to treatment, with virtually
no occurrence in plots treated with boron. Seedling uptake of applied boron was
high, with foliar concentrations of 45 p.p.m. found after the second growing
season. Foliar B levels declined to 13-15 p.p.m. after 5 growing seasons. No
significant increase in foliar magnesium levels was detected for either of the
magnesium treatments. The reduction in the incidence of leader dieback, and
shoot and foliar symptoms, in seedlings treated with B indicate that these
symptoms were the result of boron deficiencies. This is the first study to
verify boron deficiency in coastal Douglas fir through fertilizer trials.
OSU
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59. Grier, C.C., K.H. Lee and R.M.
Archibald. 1984. Effect of urea fertilization on allometric relations in young
Douglas-fir trees. Canadian-Journal-of-Forest-Research 14(6): 900-904.
Keywords: fertilization
growth
carbon allocation
tree morphology
Abstract: Twenty
three yr old trees growing on a class III site in Washington State were
fertilized with 225 kg/ha N in March 1980. Trees were measured before
fertilizing and after 1980-83 growing seasons and destructively sampled after 2
growing seasons (in Nov.-Dec. 1981 and Jan. 1982). Logarithmic regression
equations using stem diam. to predict tree biomass components were not
significantly (p = 0.05) different between fertilized and control trees for total
foliage, total branch, dead branch, stembark, or stemwood. New foliage and new
twig components, however, were higher in fertilized trees than in control
trees. Analysis of data from this and earlier studies suggests that fertilizing
will increase leaf biomass per tree relative to control trees on sites having
low nitrogen availability; however, this response will decrease with increasing
nitrogen availability. Regression equations based on regional analysis of
unfertilized trees yield estimates of foliage biomass for average trees on
average sites. If N fertilizing brings the site above average in terms of
nitrogen availability then these regression equations will underestimate
foliage biomass. However, on sites that are initially very nitrogen deficient,
N fertilizing will bring the site closer to average in terms of nitrogen
availability, resulting in more accurate predictions of foliage biomass for
fertilized stands than for control stands.
OSU
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60. Hall, T.H., R.V. Quenet, C.R.
Layton and R.J. Robertson. 1980. Fertilization and thinning effects on a
Douglas-fir ecosystem at Shawnigan
Lake:
6 year growth response. Pacific-Forest-Research-Centre,
Canadian Forestry Service Information-Report BC-X-202. 31 p.
Keywords: fertilization
thinning
growth
Abstract: Further
results are given for this stand in British Columbia
at 30 yr old [see FA 43, 1945]. Gains in gross vol. increment (over control at
24 yr old) for the 200 initially largest trees/ha were 20% for heavy thinning
alone, 51% for heavy fertilizer (urea) application alone and 139% for heavy
thinning plus heavy fertilizer application. Adjustments by covariance analysis
for differences in intitial stocking and tree size distributions gave values of
47, 76 and 139% respectively.
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61. Harrison, R., D.S. Xue, C. Henry
and D.W. Cole. 1994a. Long-term effects of heavy applications
of biosolids on organic matter and nutrient content of a coarse-textured forest
soil. Forest-Ecology-and-Management 66(1/3): 165-177.
Keywords: fertilization
soil properties
Abstract:
Long-term changes in soil properties due to a single heavy application of
municipal biosolids (municipal sewage sludge) on a coarse-textured glacial
outwash soil were evaluated. Study sites, located at the Pack Experimental
Forest, 100 km S. of Seattle, Washington, were clearcut, cleared, fertilized
with 500 t/ha of municipal biosolids and planted with either Lombardy poplar
(Populus nigra var. italica), Douglas fir (Pseudotsuga menziesii) or ponderosa
pine (Pinus ponderosa) in 1975. Soil samples were taken in 1990 from treated
stands and from adjacent (unamended) control sites by horizon to a depth of 185
cm. Biosolids-amended samples had greater amounts (mg/g) of C (139 vs. 67), N
(12 vs 3.4), P (14 vs. 2.2) and S (2.5 vs. 0.4) contents in 0-7 cm mineral soil
and other surface soil horizons, compared with control soil horizons, but
showed no significant differences below 25 cm. Soil pH ranged from 0.4 to 1.0
units lower in biosolids-amended vs. unamended soil throughout the sampled soil
horizon. Soil cation exchange capacity was higher in the surface soil horizons
of treated plots (30 vs. 18 mmolc kg-1 in 0-7 cm soil), but there were no
significant differences below 50 cm. Biosolids-amended samples had greater
amounts (mg/g) of total Ca (13 vs. 6.1 in 0-7 cm soil) and K (1.9 vs. 1.5 in
0-7 cm soil) throughout the sampled soil profile. Total Mg was relatively
constant (2.0-3.0) throughout the sampled soil profile. Study results indicate
that one of the primary objectives of the original biosolids application
(increasing total nutrients in the rooting zone of the forest soil) extended at
least 15 years from the application date.
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62. Harrison, R.B., S.P. Gessel, D.
Zabowski, C.L. Henry, D.S. Xue, D.W. Cole and J.E. Compton. 1996. Mechanisms of
negative impacts of three forest treatments on nutrient availability.
Soil-Science-Society-of-America-Journal 60(6): 1622-1628.
Keywords: fertilization
growth
soil properties
tree/stand health
Abstract: Many
forest management treatments are directly aimed at maintaining or enhancing
forest productivity. There may also be secondary effects that detract from this
goal. Three case studies in Washington
state, USA,
are discussed in which several mechanisms may have led to adverse secondary
impacts. In the first study, pulp and paper (PIT) sludges were mixed into soil
and growth of Douglas-fir (Pseudotsuga menziesii), noble fir (Abies procera)
and western white pine (Pinus monticola) was monitored. There was a significant
negative correlation of height and diameter growth and C:N
ratio for Douglas-fir and western white pine. In a second study, effects of 50
years of red alder (Alnus rubra) and Douglas-fir growth on soil chemistry and
stand productivity were compared. When the 50-year-old stands were cut and red
alder was established by planting into the soil of the former Douglas-fir and
red alder forests, a reduction in available P in the soil of the previous red
alder stand was observed. In a third study, high rates of low C:N ratio organic matter (300 t/ha) were added in municipal
biosolids (~8000 kg N/ha) to Douglas-fir and grand fir (Abies grandis)
plantations. Excess organic N in the biosolids apparently mineralized,
nitrified, and contributed to soil acidification and accelerated cation
leaching. Severe Mg deficiency (0.25 g/kg in biosolids-treated vs. 0.93 g/kg in
untreated areas) might be the cause of observed foliar chlorosis and poor
growth rates.
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63. Harrison,
R.B., C.L. Henry, D.W. Cole and D. Xue. 1995. Long-term changes in organic
matter in soils receiving applications of municipal biosolids. In Carbon
forms and functions in forest soils. Eds. W.W. McFee
and J.M. Kelly. Soil Science Society of America Inc.,
Madison WI. pp. 139-153.
Keywords: fertilization
soil properties
Abstract: Soil
concn of C, N, P, Ca, Mg, K, pH, and CEC were compared at two forest sites of
contrasting mineralogy and management in Washington,
U.S.A.,
after the application of municipal biosolids. The soil on the Pack forest site
was an extremely coarse-textured outwash soil whilst that of the Mt. Pilchuck
Tree Farm was a sandy outwash soil. The Pack forest was characterized by
80-yr-old second growth Douglas fir (Pseudotsuga menziesii) with an understory
of salal (Gaultheria shallon). The Mt. Pilchuck Tree Farm site was
characterized by 60-yr-old second growth Douglas fir with an understory of
salal. Both sites were harvested and cleared prior to the initiation of the
studies. The forest floors were different in the biosolids-amended soils
compared with the unamended soils, with more highly humified material and fewer
fine roots. Large increases in C, N, and P concn in the amended plots were
restricted to the top 27 cm of soil. Ca and Mg increases were observed at the Pack
Forest
amended site but not at the Mt. Pilchuck Tree Farm site. At both sites the pH
was lower in the amended plots. The differences between the sites are discussed
with reference to soil type and management practices. Implications for
long-term nutrient retention are considered.
Non-OSU
Link
64. Harrison,
R.B., C.L. Henry and D.S. Xue. 1994b. Magnesium deficiency in Douglas-fir and
grand fir growing on a sandy outwash soil amended with sewage sludge. Water,
Air, and Soil Pollution 75(1/2): 37-50.
Keywords: fertilization
tree/stand health
tree physiology
soil properties
Abstract: Soil
and plant samples were collected from chlorotic plantations of grand fir (Abies
grandis) and Douglas fir (Pseudotsuga menziesii) near Seattle,
Washington
state, USA,
in winter 1989. The soils had been amended in 1981 with an average of 300 dry
t/ha of municipal sewage sludge. The sludge amendment resulted in an N
application rate of approximately 8000 kg/ha. Foliage analysis indicated that a
severe Mg deficiency (0.25 g/kg in sludge-treated vs. 0.93 g/kg in untreated
areas) might be the cause of chlorosis. No other nutrient showed concentrations
in the deficient or toxic ranges. Trace metal levels in foliage were increased
significantly for Ni, Cd and Cr at sludge-treated sites, but were not at toxic
levels. Soil samples taken to a depth of 1.4 m indicated the potential for soil
acidification (up to 0.9 pH unit) in soil surface horizons. In addition,
exchangeable Ca, Mg and K may have been depleted in surface horizons. Exchangeable
Al and Fe were greater in the surface of sludge-treated sites. These
observations, and the loss of much of the nitrogen added during the sludge
amendment, indicated that nitrification and cation leaching were the most
likely mechanism for acidification and depletion of exchangeable cations.
Fertilizing the plantation with MgSO4 or dolomitic limestone was carried out in
spring 1990. New foliage collected in June 1990 was non-chlorotic and
significantly higher in Mg concentration than unfertilized foliage (1.1. vs.
0.7 g/kg, respectively). The results of this study indicate that it is
important to assess the potential for initiating a nutrient deficiency due to
secondary effects of sludge application in forest systems.
OSU
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65. Harrison,
R.B., E.C. Turnblom, C.L. Henry, P. Leonard, R. King and R. Gonyea. 2002.
Response of three young Douglas-fir plantations to forest fertilization with
low rates of municipal biosolids. Journal-of-Sustainable-Forestry 14(2/3):
21-30.
Keywords: fertilization
growth
tree/stand health
Abstract: Growth
responses were monitored in three Pseudotsuga menziesii stands (Units 2, 11 and
13) in Washington, USA, following single low applications (17-19 t/ha) of
municipal biosolids amendment. At the last measurement, in 1995, there were a
total of 162 vs. 137 live trees (per 0.121 ha of 3 plots) in unit 2, 94 vs. 137
in unit 11, and 100 vs. 110 in unit 13 in control vs. biosolids-treated plots,
respectively. The response ranged from 0.4 to 2.2 cm for average diameter at
breast height, and -0.03 to 0.64 m for average total height. The small negative
response could be due to mortality of trees or small errors in height
measurements. The response in per ha values ranged from 0.8-5.2 m2/ha for basal
area, 9-39 m3/ha for volume, and 3965-16 107 kg/ha for dry weight.
OSU
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66. Heath, L.S. and H.N. Chappell.
1989. Growth response to fertilization in young Douglas-fir stands.
Western-Journal-of-Applied-Forestry 4(4): 116-119.
Keywords: fertilization
thinning
growth
Abstract:
Response surface methodology was used to estimate 6-yr vol. growth response to
1 application of 200 lb N/acre in unthinned and thinned Douglas fir
(Pseudotsuga menziesii) stands of b.h. age <less or =>25 yr in W.
Washington and W. Oregon. Regional mean fertilizer response was 16% in
unthinned stands and 20% in thinned stands. Site index had an increasingly
inverse effect on response as b.a. increased in both
unthinned and thinned stands. Response varied little over site index in regions
of low b.a., decreased moderately as site index
increased in the intermediate region, and decreased rapidly in the high b.a.
region.
OSU
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67. Henry, C.L., D.W. Cole and R.B.
Harrison. 1994. Use of municipal sludge to restore and improve site
productivity in forestry: The Pack Forest Sludge Research Program.
Forest-Ecology-and-Management 66(1/3): 137-149.
Keywords: fertilization
growth
soil properties
stand conditions
Abstract:
Municipal wastewater residuals - sludge or biosolids - represent a major waste
by-product from society that must be managed in responsible ways. Because of
its high nutrient and organic matter content, sludge can be beneficially
recycled into forest sites for site improvement purposes. This paper reviews
the opportunities and problems that have been encountered during 20 yr of
research into sludge application in forests, based on data from studies carried
out in the Pack Demonstration Forest, Washington, on a variety of sites -
including clear-felled, young or mature Douglas fir [Pseudotsuga menziesii]
stands, and rights-of-way. Research to date on forest application of sludge has
been very encouraging, clearly demonstrating the validity of this management
technique. Forest
sites typically display benefits in two ways: (1) an immediate growth response
by both overstorey and understorey species; (2) a long-term improvement to the
productivity of the site. However, for this practice to have broad utility and
acceptance, it is critical that the concerns of the regulatory agencies and
general public be addressed regarding public health and environmental issues
through continued research. These concerns include the fate of trace metals,
including movement, uptake and potential phytotoxicity, and passage into wildlife
and human food chains, the fate of pathogens, and leaching of nitrates into
groundwater systems. Many concerns are a result of misconceptions or
misunderstandings of the potential problems involved and require working with
these agencies and the general public through education and demonstration
programmes.
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68. Henry, C.L., D.W. Cole, T.M.
Hinckley and R.B. Harrison. 1993. The use of municipal and pulp and paper
sludges to increase production in forestry. Journal-of-Sustainable-Forestry
1(3): 41-55.
Keywords: nursery operations
nursery fertilization
fertilization
thinning
growth
tree/stand health
soil properties
Abstract: Because
of their high nutritional content and soil conditioning properties, municipal
and pulp and paper (P&P) sludges (biosolids) can serve as soil amendments
for nutritionally deprived or organically poor soils on forest sites. Studies
conducted over the past 20 years at an experimental forest site in Western
Washington, USA,
have largely confirmed the potential of biosolids to increase the productivity
of many forest lands. These studies clearly demonstrated that application of
biosolids at environmentally acceptable rates will result in growth responses
for both young seedlings as well as established stands. Municipal biosolids
have been applied to a number of Douglas fir (Pseudotsuga menziesii) stands.
Young stands treated with 47 t/ha showed an average of 72, 14 and 2% height
responses for Site Class IV, III and II, respectively, over a 10 year period.
Thinned versus unthinned 55-year-old Douglas fir treated with 142 dry t/ha
averaged 43 and 48%, respectively, for the 12 year period greater than
controls. Average growth responses of 65 and 40% occurred in the 65-year-old
stand for the Site Class IV and II, respectively, from a 47 dry t/ha
application. Growth response resulting from application of P&P biosolids to
a number of tree species (Douglas fir, Pinus monticola and Abies procera in
nursery beds, and plots of Populus deltoides x P. trichocarpa rooted cuttings)
has also been excellent. When properly applied, biosolids can provide an
excellent alternative to chemical fertilizers as a means of enhancing forest
production. Growth response is typically greater and lasts longer when compared
with chemical fertilizers.
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69. 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 Europe and South
America, and in New
Zealand and Australia,
as well as throughout its extensive natural range in western North
America. Decades of experience with the silviculture
of young stands have demonstrated that practices such as planting, the use of
genetically improved seedlings, precommercial and commercial thinning, and
fertilizing may dramatically increase the yield of industrial products over
that of natural forests. Further, such silviculture is compatible with the
production of desired amenities. Vigorous implementation of such practices
wherever Douglas fir is cultivated will increase the world's timber resources,
and be an effective strategy for reducing the pressure, occasioned by the
world's rapidly increasing population, to harvest the fragile tropical and
boreal forests.
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70. Hetherington, E.D. 1985. Streamflow nitrogen loss following forest fertilization in a
southern Vancouver Island
watershed. Canadian-Journal-of-Forest-Research 15(1): 34-41.
Keywords: fertilization
soil properties
Abstract: Water
quality was monitored in the Lens Creek catchment to determine nitrogen loss
following aerial application of 224 kg/ha N (as urea) to a second-growth Douglas-fir
forest in Sept. 1974. Peak nitrogen concentrations measured in 2 small
tributary streams were 14 mg/litre as urea (after 12 h), 1.9 mg/litre as
ammonia (after 24 h), and 9.3 mg/litre as nitrate (after 7 wk). For the first
14 months, estimated nitrogen outputs in excess of background amounts were 5.9
and 14.5% respectively of the total nitrogen applied to the 2 subsidiary
catchments which had 46 and 80% of their drainage areas fertilized. These
losses were considerably higher than amounts of <1% previously reported for
western North America.
Increased amounts of urea N and ammonia N were short-lived, while nitrate N
remained above background values for the duration of the study. Reasons for the
high nitrogen loss include nitrification of the urea during 7 wk of mild, dry
weather following fertilizing, the presence of alder and swampy areas adjacent
to the streams, high soil permeability, steep slopes, and abundant, above
average early winter rainfall. The catchments had been fertilized previously in
1967-68 and 1972 but any influence of this on nitrogen loss during the present
study is unknown. Lens Creek water quality was not adversely affected by the
fertilizing in terms of drinking water standards or toxicity to fish.
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71. Homann, P.S., B.A. Caldwell, H.N.
Chappell, P. Sollins and C.W. Swanston. 2001. Douglas-fir soil C and N
properties a decade after termination of urea fertilization.
Canadian-Journal-of-Forest-Research 31(12): 2225-2236.
Keywords: fertilization
soil properties
Abstract: Chemical
and microbial soil properties were assessed in paired unfertilized and urea
fertilized (>89 g N/m-2) plots in 13 second-growth Douglas fir (Pseudotsuga
menziesii) stands distributed throughout western Washington and Oregon, USA. A
decade following the termination of fertilizer application, fertilized plots
averaged 28% higher total N in the O layer than unfertilized plots, 24% higher
total N in surface (0-5 cm) mineral soil, and up to four times the amount of
extractable ammonium and nitrate. Decreased pH (0.2 pH units) caused by
fertilizer application may have been due to nitrification or enhanced cation
uptake. In some soil layers, fertilizer application decreased cellulase
activity and soil respiration but increased wood decomposition. There was no
effect of fertilizer application on concentrations of light and heavy
fractions, labile carbohydrates, and phosphatase [phosphoric monoester
hydrolases] and xylanase activities. No increase in soil organic C was detected,
although variability precluded observing an increase of less than ~15%. Lack of a regionwide fertilizer application influence on soil
organic C contrasts with several site-specific forest and agricultural studies
that have shown C increases resulting from fertilizer application.
Overall, the results indicate a substantial residual influence on soil N a
decade after urea fertilizer application but much more limited influence on
soil C processes and pools.
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72. Hong, S. and J.J. Morrell. 1997.
Treatability of Douglas-fir heartwood with ACZA or CCA: effect on site,
silvicultural practice, and wood properties. Forest-Products-Journal 47(10):
51-55.
Keywords: planting operations
fertilization
thinning
wood quality
Abstract: The
effects of site, silvicultural treatments, and wood properties on treatability
of Douglas-fir (Pseudotsuga menziesii) heartwood, from Washington
and Oregon,
with chromated copper arsenate (CCA) or ammoniacal copper zinc arsenate (ACZA)
were studied. Thinning appeared to be associated with slight improvements in
treatability (penetration and retention of preservative), but combinations of
thinning and fertilization had no significant effect on this property. Other
factors such as site, height from which the sample was removed, and percentage
of juvenile wood had inconsistent effects on treatability. Although the results
indicate that silvicultural practices have minimal effects on treatability of
Douglas-fir, further studies are required to clarify these effects.
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73. Hopmans, P. and H.N. Chappell.
1994. Growth response of young, thinned Douglas-fir stands to nitrogen
fertilizer in relation to soil properties and tree nutrition.
Canadian-Journal-of-Forest-Research 24(8): 1684-1688.
Keywords: fertilization
growth
soil properties
tree physiology
Abstract: Application
of 224 kg N/ha to young, thinned stands of Douglas fir (Pseudotsuga menziesii)
at 35 sites in W. Oregon and Washington significantly increased basal area and
volume increment over 8 years following treatment. However, response varied
considerably between sites, and relative volume increment exceeded 10% at only
19 of the 35 sites. Response to applied N was evaluated in relation to forest
floor and soil variables as well as to levels of N in foliage. Relative
responses in basal area and volume were significantly correlated with total N
concentration and the C/N ratio of the soil. However, these relationships
explained only part (18-22%) of the observed variation in response. In
contrast, relative response was strongly correlated with the level of N in the
foliage of non-fertilized trees at 11 sites, accounting for 94% of the
variation between sites. It is suggested that foliar N could be used to predict
growth responses to N fertilizers in young thinned Douglas fir stands.
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74. Jacobs, D.F., R. Rose, D.L. Haase and P.D. Morgan. 2003b.
Influence of nursery soil amendments on water relations, root architectural
development, and field performance of Douglas-fir transplants. New-Forests
26(3): 263-277.
Keywords: nursery
operations
fertilization
tree physiology
tree morphology
growth
carbon allocation
soil properties
tree/stand health
Abstract:
This experiment evaluated the influence of manure, peat, and vermiculite
incorporated at low and high rates (0.0118 and 0.0236 m3/m2) and under two soil
moisture regimes on Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedling
(1+0 for 1+1) xylem water potential ( Phi xylem),
whole-plant growth, root architectural development, and subsequent field
performance under fertilized and non-fertilized conditions. Trends in soil
moisture retention were observed (high manure > high peat > control) but
there were no differences in Phi xylem. Root length in the wetter soil moisture
experiment was initially (three months) greatest for seedlings in high
vermiculite and least in high manure but there were no differences among
treatments at lifting (eight months). Mean height was greatest for seedlings
grown in vermiculite and peat (wetter nursery experiment) after two field
seasons. Field fertilization (35 g/seedling) with controlled-release fertilizer
in the planting hole stimulated height growth
initially, but decreased height and diameter growth during the second growing
season. Dramatic improvements associated with the use of nursery soil
amendments were not realized, but the failure to identify negative effects, a
potential reduction in disease incidence, and improvement of nursery soil
physical and chemical properties may justify their use.
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75. Jozsa, L.A. and H. Brix.
1989. The effects of fertilization and thinning on wood quality of a
24-year-old Douglas fir stand. Canadian-Journal-of-Forest-Research 19(9): 1137-1145.
Keywords: fertilization
thinning
wood quality
growth
Abstract:
The effect of thinning and N fertilization on growth and wood density
of coastal Douglas fir (Pseudotsuga menziesii) on a poor site on Vancouver
Island (British Columbia) is
described for plots established at approx. 24 yr old in 1971-72. Stem cores
were taken using an increment borer in Mar.-Apr. 1984. Ring-width and
ring-density data were obtained from pith to bark for all trees using
computerized X-ray densitometry. Fertilization reduced ring density at b.h. and
25% stem ht. by an av. of 6% for a 3- to 4-yr period after treatment, but not
thereafter. Reductions in ring density resulted from decreases in the density
of earlywood and latewood, as well as from decreases in latewood percentages.
Effects were only pronounced in the lower half of the stem. Thinning resulted
in a slight increase in ring-density in the lower bole and a reduction in the
top. The combined treatments had an intermediate effect on ring density. Ring
density showed an increasing trend from pith to bark at all ht. except at 75%
stem ht., and a decrease with increasing ht. in the
bole. Fertilization and thinning both increased diam. growth, and the
beneficial effects were still evident 13 yr after treatments.
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76. Kabzems, R.D. and K. Klinka. 1987. Initial quantitative
characterization of soil nutrient regimes. I. Soil properties.
Canadian-Journal-of-Forest-Research 17(12): 1557-1564.
Keywords: fertilization
soil properties
Abstract:
Data on properties of the forest floor and mineral soil were collected
from 6 Douglas fir ecosystems on southern Vancouver
Island. Data were analysed to determine whether soil
properties reflecting nutrient status differed significantly from soil nutrient
regimes assessed using selected vegetation, environmental and physiographic
features. The sum of mineralizable N, total N and exchangeable Ca and Mg in
mineral soil and forest floor were the properties that best characterized the
soil nutrient regimes recognized in this study (poor, medium, rich, very rich).
Previous application of N fertilizer did not appear to change soil N status
sufficiently to alter the classification. Both discriminant and cluster
analyses consistently differentiated the soil nutrient regimes using
exchangeable Mg and mineralizable N in forest floor plus mineral soil. The
consistency of these groupings suggests that important differences between the
nutrient regimes could be identified using soil properties alone.
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77. Kershaw, J.A., Jr. and D.A. Maguire. 1996. Crown structure in
western hemlock, Douglas-fir, and grand fir in western Washington:
horizontal distribution of foliage within branches.
Canadian-Journal-of-Forest-Research 26(1): 128-142.
Keywords: fertilization
tree morphology
Abstract:
Horizontal distribution of foliage within individual branches was explored for
western hemlock (Tsuga heterophylla), Douglas fir (Pseudotsuga menziesii) and
grand fir (Abies grandis), three major tree species in the Pacific Northwest. Weibull, beta , normal, and Johnson's SB distributions were assessed
for their ability to conform to the empirical foliage distributions.
Moment-based parameter recovery and parameter prediction methodologies were
applied. On the basis of the rank of individual branch chi superscript
2-values, the beta distribution performed best under parameter recovery, while
Johnson's SB distribution was best in terms of total sum of chi superscript
2-values. Overall, few differences between the four distributions were
observed. A system of moment-based parameter prediction equations was developed
from branch dimensional and positional measures. The prediction equations
showed that the ratio of relative distances from the stem to mean foliage
density increased with increasing branch size. This relative increase was
enhanced with increasing depth into crown for western hemlock, but not for
Douglas fir or grand fir. Again, the beta distribution, based on predicted
moments, followed most closely the empirical distributions on the basis of the
ranks of chi superscript 2-values. The normal distribution was the best in
terms of total sum of chi superscript 2-values. As expected, moment-based
parameter recovery produced smoothed distributions that followed more closely
the observed empirical distributions; however, parameter prediction provides a
methodology for predicting distributions when empirical moments are not
available. No significant (p >0.05) differences in horizontal foliage
distribution were found between sites or fertilizer (0 or 225 kg N/ha as urea)
treatments.
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78. Kimball, B.A., E.C. Turnblom, D.L. Nolte, D.L. Griffin and R.M.
Engeman. 1998b. Effects of thinning and nitrogen fertilization on sugars and
terpenes in Douglas-fir vascular tissues: implications for black bear foraging.
Forest-Science 44(4): 599-602.
Keywords: fertilization
thinning
tree/stand protection
tree physiology
tree/stand health
Abstract:
Analyses of vascular tissue samples from Douglas fir (Pseudotsuga menziesii)
trees collected in test plots in W. Washington
and NW Oregon, USA,
showed that both thinning and N fertilizer application caused the sugar
concentration of vascular tissues in the lower bole to increase. However, these
treatments had no effect on the concentrations of hydrocarbon monoterpenes,
oxygenated monoterpenes or sesquiterpenes. These results may explain the
observations that black bears (Ursus americanus) prefer to forage in thinned and
fertilized stands, as the bears maximize sugar intake and minimize terpene
intake while foraging.
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79. Lavender, D.P. and R.B. Walker. 1981. Nitrogen and related
elements in nutrition of forest trees. In Proceedings: Forest
Fertilization Conference, University of Washington, Seattle, Washington,
USA.
Eds. S.P. Gessel, R.M. Kenady and W.A. Atkinson. pp.
15-22.
Keywords: fertilization
tree physiology
soil properties
mycorrhizal response
Abstract:
This paper discusses the principal inorganic ions used by forest trees
and their respective roles in tree physiology, their common range of
concentration in coniferous foliage, and the general symptoms associated with
their deficiency. The factors governing effective concentrations of each ion at
an active metabolic site are redistribution or internal nutrient cycling,
nutrient uptake, and soil status (temperature, moisture, and concentration of
each nutrient). Also described are endogenous patterns of nutrient storage and
translocation, and the possible effects of fertilizers upon them and upon the
mechanisms of ion uptake, especially the effect of pH change associated with
urea applications upon the mycorrhizal complement of western hemlock (Tsuga
heterophylla).
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80. Lee, Y.J. and H.J. Barclay. 1985. Ten-year
growth response of a 25-year-old and a 55-year-old Douglas-fir stand to
thinning and urea fertilization. Pacific-Forestry-Centre,
Canadian-Forest-Service Information-Report BC-X-260. 14
p.
Keywords: fertilization
thinning
growth
tree/stand health
Abstract:
In stands of medium site quality in British Columbia,
4 rates of nitrogen (0, 112, 224, and 336 k/ha of N), in the form of urea (46%
N), were tested at two thinning intensities. Fertilizer was applied in spring
or fall, but the season of application had little effect on growth. Thinning
almost doubled diam. growth by 10 yr but affected only net vol. growth; gross
vol. was only minimally affected by thinning. Fertilization in the 25-yr-old
stand increased mean d.b.h. growth significantly in the second and third yr and
increased vol. growth significantly in the first 3 yr, but the effect
diminished thereafter. Different rates of fertilizer application on the
55-yr-old stand gave inconsistent results. Combined thinning and fertilizer
treatment had the greatest growth response. In both stands the overall effect
of 336 kg/ha N was to increase vol. growth by about 20%. Thinning significantly
decreased mortality, but the effect of fertilizer was negligible. Combined
treatment had the greatest effect on the advancement of trees by the number of
d.b.h. classes. The effect of thinning and fertilizing on the cumulative growth
will probably continue after 10 yr until crowding sets in.
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81. Luxmoore, R.J., M.L. Tharp and R.A. Efroymson. 1999. Comparison of
simulated forest responses to biosolids applications.
Journal-of-Environmental-Quality 28(6): 1996-2007.
Keywords: fertilization
growth
Abstract:
Organic matter and N were added to humus pools of the LINKAGES simulator of
forest growth and N cycling at a range of application rates to investigate
long-term effects of biosolids (sewage sludge) on forest productivity. The
simulation was done for 2 conifer plantations (Douglas fir, Pseudotsuga
menziesii var. menziesii on the coast range of Washington state, USA; and
loblolly pine, Pinus taeda on the Piedmont soils of Georgia) and a northern
hardwood forest located in New Hampshire. Single applications of biosolids were
given at 0, 5, 10, 20, and 40 Mg/ha, and multiple applications on 7 occasions
at 3-yr intervals at rates of 5 and 10 Mg/ha. Highly significant increases in
aboveground phytomass and net primary productivity of Douglas fir plantations
were obtained in a 100-yr simulation with increasing biosolids application
rates. Results for loblolly pine from a 50-yr simulation produced about half
the growth response of Douglas fir. Long-term simulations of northern hardwoods
showed modest growth responses and small increases in NPP (net primary
productivity) with added biosolids. The phytomass of one overstorey and 3
understorey species in the hardwood forest changed in response to different
biosolids applications and varying species sensitivity to N supply. It is
concluded that biosolids are a significant resource for enhancing forest
productivity, particularly in conifer plantations. Estimates of N leaching
losses from simulated forest sites combined with a literature review of
leaching losses suggest that biosolids applications at 3-yr intervals with rates
less than 8.5 Mg/ha (0.4 Mg N/ha) during active forest growth may pose little
off-site contamination risk to ground water or surface waters.
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82. Marshall, V.G. and H.J. Barclay. 1994. Response of young
Douglas-fir to urea fertilizer applied on and off snow. Forestry-Chronicle
70(3): 294-298.
Keywords: fertilization
growth
Abstract:
The effects of 200 kg N ha-1 applied as urea fertilizer on 50 cm of snow or on
bare ground were studied in an 11-year-old Douglas fir (Pseudotsuga menziesii)
plantation on Vancouver Island.
Core samples were taken from all trees on the plot 6 yr after treatment; height
was measured for 20 selected dominant trees per plot 3 months and 4 yr after
treatment. Up to 2 years following treatment, urea significantly increased
absolute DBH increments over controls in all trees and the 20 selected trees
per plot; response to fertilizer application on snow was equal to that on bare
ground. Between the 3rd and 9th year following treatment, mean DBH increments
were not significantly different for any treatment. Four-year absolute volume
increments were 63 and 87% greater than the controls for bare-ground and
on-snow applications, respectively.
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83. McLeod, A.A., R.C. Evans and R.K. Scagel. 1993. Conversion of
understocked salal sites at Woss Lake, British Columbia.
B.C. Ministry of Forests FRDA-Report 194. vi + 15 p.
Keywords: nursery
operations
site preparation
mechanical preparation
fertilization
growth
tree/stand health
economics
Abstract:
A trial comparing the effect of spot scarification and slow release NPK
fertilizer application on stock types of coastal Douglas fir (Pseudotsuga menziesii)
was conducted in a 25-year-old backlog site occupied by a thick carpet of salal
(Gaultheria shallon) in the CWHxm2 habitat of Vancouver Island, British
Columbia. Bare root and container stock types were planted and treated, and
mortality and growth were measured for 3 years. Despite the high
fertilizer-related mortality of the bare-root stock type in the first year, the
3-year height growth performance of all treatments was better but more variable
than that of the untreated seedlings. The value of site
preparation and fertilizer for stimulating early growth varied by stock type.
Bare-root stock did not respond strongly enough to fertilizer or site
preparation to justify the cost of either of these treatments. Container stock
types did not respond strongly enough to site preparation alone to justify the
high cost of site preparation. The largest growth gains in the container stock
types were associated with the combination of site preparation and
fertilization.
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84. Mikels, R.A. 1983. Melamine, a controlled
release fertilizer for conifer seedlings. Forestry-Abstracts 44(11):
698.
Keywords: fertilization
growth
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85. Miller, R.E. 1981. Response of Douglas-fir to
foliar fertilization. In Proceedings: Forest
Fertilization Conference, University of Washington, Seattle, Washington,
USA.
Eds. S.P. Gessel, R.M. Kenady and W.A. Atkinson.
pp. 62-68.
Keywords: fertilization
tree/stand health
growth
economics
Abstract:
This paper summarizes past research about spray application of 10 to
32 percent nitrogen solutions to seedlings and established stands of
Douglas-fir. These investigations establish that Douglas-fir and associated
conifers can be foliarly fertilized with concentrated nitrogen solutions at
dosages of 50 to 200 pounds per acre; however, fertilization with these
solutions requires more critical selection of nitrogen source, dosage,
additives, and, perhaps, time of year than does fertilization with urea prill.
Some burning, up to about 30 percent of the needle surface, is visually
disturbing but probably has no measurable effects on growth. With low dosages
and careful application, gains in cubic volume or height growth per pound of
applied nitrogen were similar for both spray and prill. Yet costs per pound of
applied nitrogen have been about 25 percent more for 32 percent nitrogen solutions
than for prilled urea. Hence, foliar application of concentrated nitrogen
solutions is currently less cost effective than conventional use of urea solids
for fertilizing Douglas-fir and associated conifers.
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86. Miller, R.E., M.V. Atherton and J.E. Wilcox. 1986. Comparative
effects of three nitrogen fertilizers applied in fall and spring to a
29-year-old Douglas-fir plantation. Canadian-Journal-of-Forest-Research 16(5):
910-917.
Keywords: fertilization
growth
tree/stand health
tree physiology
Abstract:
Stand growth and mortality were monitored for 13 yr after application
of urea, ammonium nitrate or urea + ammonium sulphate (224 kg N/ha) in autumn
1967 and spring 1968 to plots in a 29-yr-old Douglas fir plantation on
Vancouver Island, British Columbia. The treatments and a control were
replicated 3 times. Foliar analysis indicated insufficient available N before
treatment and an increase in available N 1 and 2 yr after fertilization.
Addition of N at this location did not have a practical effect on stand growth
and the field experiment was not sufficiently sensitive to detect real
differences between N sources or season of application. Suggestions are
included for improving field trials.
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87. Miller, R.E., G.W. Clendenen and D. Bruce. 1988. Volume growth and
response to thinning and fertilizing of Douglas-fir stands in southwestern Oregon.
Pacific-Northwest-Research-Station,-USDA-Forest-Service
General-Technical-Report PNW-GTR-221. ii + 38
p.
Keywords: fertilization
thinning
growth
Abstract:
Data were collected from 114 thinning (felling 15-80% of initial basal
area) and/or fertilizer application (usually urea at 200 or 400 lb N/acre) trials
in naturally regenerated Douglas fir (Pseudotsuga menziesii) stands in SW
Oregon (111 stands) and N. California (3 stands). The data were used to develop
regression equations to estimate volume growth for a 10-yr period of treated
and untreated stands, aged 10-70 yr. The predictions for SW Oregon (SWOR) were
compared with other growth predictions including DFSIM, a simulation model
based on a broader, regional database. SWOR consistently showed greater gross
and net growth of untreated Douglas fir and showed greater benefits of nitrogen
fertilization, especially on poor quality sites and in young stands in the
subregion than did DFSIM. SWOR predicted reduced gross volume growth during the
10 yr after thinning, faster recovery from early thinning on good than on poor
sites, and increased wood production after nitrogen treatment in 70% of thinned
and unthinned Douglas fir stands.
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88. Miller, R.E., J.W. Hazard and D.C. Young. 1991. Effects of foliar
spray and prill applications of nitrogen fertilizer on four mixed-conifer
stands. Forest-Science 37(3): 741-754.
Keywords: fertilization
growth
tree/stand health
Abstract:
Concentrated urea-ammonium nitrate solution (32% N) and urea prill (granules;
46% N) were applied by helicopter at dosages of 56, 112, 224 and 448 kg N/ha
before (5 May) and during (14 July) the 1969 growing season to four 40- to
70-year-old mixed stands of Pseudotsuga menziesii and Tsuga heterophylla near
Sequim, Washington. Stand growth was measured repeatedly in the next 10 years.
Helicopter application of both fertilizers was variable and therefore weakened
comparisons between prill and foliar sprays and spring vs. summer applications.
Applying 112 kg N/ha or more to these poor-site stands increased gross and net
volume growth; volume growth was related linearly to N dosage of both prill and
spray. Gains from prill apparently exceeded those from spray, but a subsampling
of plots indicated that actual dosages, especially of spray, were less than
target dosages. At the target dosage of 224 kg N/ha, 10-year gains in gross
growth averaged 34.0 msuperscript 3/ha (30%) and 8.0 msuperscript 3/ha (7%)
after prill and spray, respectively. Although fertilizer treatment accelerated
tree losses, cumulative volume of dead trees was less than 15% of gross volume
growth. Season of fertilization seemed to have no effect on efficiency of
either prill or spray, but suspected differences between actual and target
dosages may have influenced this comparison. Concentrated N solution applied at
dosages up to about 224 kg N/ha caused little or no increase in foliar or tip
damage. Doubling this conventional dosage and applying in the growing season,
however, increased visible damage and may have reduced gains in volume growth.
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89. Miller, R.E., D.H. McNabb and J. Hazard. 1989. Predicting Douglas
fir growth and response to nitrogen fertilization in western Oregon.
Soil-Science-Society-of-America-Journal 53(5): 1552-1560.
Keywords: fertilization
growth
soil properties
stand conditions
Abstract:
The objective of this study was to determine the efficacy of various
stand (site index, age, and relative density), climatic (total precipitation,
average daily solar radiation), site (elevation, soil depth, and available
water-holding capacity), and soil-test variables (anaerobically mineralized N,
total N, organic matter, and C:N ratio) to predict
relative and absolute response of Pseudotsuga menziesii stands to a single
application of 224 Kg/N ha as urea. The core equation with stand variables
accounted for 70% of residual variation in average annual volume growth.
Predicting response of fertilized stands proved much less precise. The best
core equation explained 37% of the residual variation for average percentage
response in volume growth and explained less variation in absolute response in
both volume and basal area. Of the site, climatic, and soil-test variables, C:N ratio in the surface soil was the only one that
significantly increased precision of the core equations. The best combined
equation explained 46% of the variation in percent volume response. The
anaerobic N mineralization test failed to make a significant contribution to
the core equation and had a lower correlation with response than did the C:N ratio. Stand variables remain the most reliable
predictors of fertilizer response in this region; any improvement from
including soil data for N or organic matter is not justified because of their
additional cost.
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90. 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-Forest-Service Research-Paper PNW-RP-513. ii + 25 p.
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 Oregon.
Alder densities of 0, 20, 40, and 80 per acre were tested. A fifth treatment
eliminated nitrogen-fixing alder, but substituted nitrogen fertilizer.
Treatment 6 had neither thinning nor alder control. Treatments were randomly
assigned within each of three blocks in a 9-year-old plantation. Stand density
was reduced within 15 of these 18 experimental units. Surplus conifers were
cut, but surplus red alder were controlled by the "hack-and-squirt"
method. Because numerous trees of other species regenerated naturally, combined
density of all species before thinning ranged from 1400 to 5700 trees per acre.
Subsequent 17-year change in number, average height, basal area, and volume of
Douglas-fir were compared. Retaining 20, 40, or 80 alder per
acre reduced numbers of associated Douglas-fir by about 10, 17, and 23 percent,
respectively. In pure Douglas-fir plots, gross volume growth was similar
for non-fertilized and fertilized plots, indicating no measurable benefits of
additional nitrogen. In mixed stands, red alder reduced yield of associated
Douglas-fir, but not yield of combined species. Similar comparisons are needed
at other locations, especially those with known nitrogen deficiency.
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91. Miller, R.E., D.L. Reukema and J.W. Hazard. 1996. Ammonium
nitrate, urea, and biuret fertilizers increase volume growth of 57-year-old
Douglas-fir trees within a gradient of nitrogen deficiency. Pacific-Northwest-Research-Station,-USDA-Forest-Service Research-Paper PNW-RP-490. 12 p.
Keywords: planting
operations
fertilization
growth
Abstract:
Growth of dominant and codominant Pseudotsuga menziesii given 224 kg
N/ha as ammonium nitrate, urea or biuret (a slow-release N source) in a
N-deficient plantation in SW Washington was recorded over an 8-year period in
relation to distance of the trees from a strip of the plantation interplanted
with N-fixing Alnus rubra. Adjusted mean volume growth of the measured trees
was increased by 22-28% on the east side of the mixed stand centreline and by
11-14% on the west side, with no difference in response to the 3 fertilizers.
Only biuret stimulated growth within the mixed strip of the stand. Biuret had
no visible toxic effect on competing vegetation.
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92. Miller, R.E., J. Smith and H. Anderson. 2001. Detecting response
of Douglas-fir plantations to urea fertilizer at three locations in the Oregon Coast Range.
Pacific-Northwest-Research-Station,-USDA-Forest-Service
Research-Paper PNW-RP-533. 20 p.
Keywords: fertilization
thinning
growth
tree/stand health
Abstract:
Fertilizer trials in coast Douglas-fir (Pseudotsuga menziesii var. menziesii)
in the Oregon Coast Range (USA) usually indicate small and statistically
non-significant response to nitrogen (N) fertilizers. Inherently weak
experimental designs of past trials could make them too insensitive to detect
growth differences that actually exist. Ability to detect real differences
among treatments should be improved by having more than two replications per
treatment and by using covariance analysis to adjust observed treatment means
for unequal starting conditions among experimental treatments. To demonstrate
these assumptions, we used size at fertilizer application and a pre-fertilizer
application (calibration) period of growth as covariates when analysing data
from five coastal plantations at three locations: Toledo North, Toledo South
and Bone Mountain.
The trials had three to six replications per treatment and calibration periods
of 6 or 7 years. Nitrogen fertilizer (urea at 200 lb N/acre) was assigned
randomly to half the plots at each location when trees were 16 or 17 years old
from seed. Our objectives were to quantify 4- or 7-year response to N
fertilizer and to demonstrate practical means for detecting response. Effects
of fertilizer application on tree diameter and height,
and on basal area and volume growth per acre were estimated. Among the five
non-thinned plantations, observed gross basal area growth was changed by -2 to
13% in the 4 or 7 years after fertilizer application. In the thinned portion of
one plantation, there were few differences in response to fertilizer between
thinned and unthinned plots. Observed responses were increased substantially by
covariance analyses at some plantations but decreased at others. Random
assignment of three to six plots per treatment did not ensure balanced or
comparable plots for fertilized and non-fertilized treatments.
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93. Miller, R.E. and S.R. Webster. 1981. Fertilizer response in mature
stands of Douglas-fir. In Proceedings: Forest
Fertilization Conference, University of Washington, Seattle, Washington,
USA.
Eds. S.P. Gessel, R.M. Kenady and W.A. Atkinson.
pp. 126-132.
Keywords: fertilization
growth
economics
Abstract:
Published and unpublished response data from fertilizer trials in mature stands
of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) in western Washington and Oregon
are examined. Stand age ranged from 60 to 120 years. It is concluded that: (1)
nitrogen fertilization increased volume growth by 9 to 60 percent in these 60-
to 120-year-old stands, (2) sizeable gains occurred in the first decade after
fertilization, (d) the economics of high stumpage values and short investment
periods make fertilizing mature Douglas-fir economically attractive.
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94. Mitchell, A.K., H.J. Barclay, H. Brix, D.F.W. Pollard, R. Benton
and R. DeJong. 1996. Biomass and nutrient element dynamics in Douglas-fir:
effects of thinning and nitrogen fertilization over 18 years.
Canadian-Journal-of-Forest-Research 26(3): 376-388.
Keywords: fertilization
thinning
precommercial thinning
carbon allocation
tree physiology
growth
soil properties
Abstract:
The effects of thinning (two-thirds of basal area removed) and N fertilizer
(448 kg N/ha as urea) on biomass and nutrition of a 24-year-old Douglas fir (Pseudotsuga
menziesii) stand at Shawnigan Lake, British Columbia, were studied over 18
years. At years 0, 9, and 18 after treatments, the aboveground biomass and N,
P, K, Ca, and Mg contents of stemwood, stem bark, foliage, and dead and live
branches were determined (kg/ha), and increments in these properties (kg/ha per
year) were calculated for the 0-9 and 9-18 year periods. Foliar biomass was
increased by both treatments during the first period and also by thinning in
the second period. Aboveground net primary production (ANPP) per unit of
foliage biomass (foliage efficiency) was increased by treatments in the 0-9
year period. The combined effects of increased foliage mass and foliage
efficiency resulted in increased total biomass production. Thinning and
fertilizer application increased the uptake of all elements except for P with
fertilizer. This increase may have contributed to the long-term increase in
stem growth. Retranslocation of elements before foliage shedding was important
for tree nutrition, but was not improved by fertilizer during the 9-18 year
measurement period. The efficiency of N use in dry matter production (ANPP/unit
of N uptake) was decreased by fertilizer. This implied that poor sites would
respond to fertilizer better than rich sites.
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95. Mitchell, A.K. and T.M. Hinckley. 1993. Effects of foliar nitrogen
concentration on photosynthesis and water use efficiency in Douglas-fir.
Tree-Physiology 12(4): 403-410.
Keywords: fertilization
tree physiology
photosynthesis
Abstract:
Leaf-level physiological processes were studied in Douglas fir
(Pseudotsuga menziesii) to determine whether apparent increases in stand-level
water use efficiency (WUE) observed in response to nitrogen (N) fertilization
were attributable to foliar N effects on carbon fixation rates or on stomatal
control of water loss. Photosynthesis and transpiration were measured at
different light intensities and ambient CO2 molar fractions and comparisons
were made between current-year shoots with average foliar N concentrations of
1.58% (high-N) and 1.25% (low-N). Photosynthetic rates and foliar N
concentrations were positively correlated. In response to light, photosynthesis
and stomatal conductance were closely coupled and a similar coupling was
observed in response to different ambient CO2 concentrations. Partitioning the
photosynthetic responses into mesophyll and stomatal components indicated that
foliar N altered mesophyll conductance but not stomatal control of water loss.
High-N shoots had significantly greater rates of photosynthesis and
transpiration than low-N shoots and, as a result, instantaneous WUE did not
differ significantly between high-N and low-N shoots.
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96. Montigny, L.d. and S. Stearns-Smith. 2001. Douglas-fir
fertilization with biosolids: five-year results at Whistler, B.C.
B.C.-Ministry-of-Forests Extension-Note 50. 6 p.
Keywords: fertilization
growth
tree/stand health
Abstract:
Biosolids (from municipal waste water treatment facilities) at 750, 1000, and
1500 kg-N/ha and conventional fertilizer at 225 kg-N/ha were applied in each of
three seasons (spring, summer, and fall) to a 15-year-old B.C. coastal
Douglas-fir (Pseudotsuga menziesii) plantation that had recently been
precommercially thinned and pruned. Five-year results showed that rate and
timing effects were independent. No height-growth response was evident, but
annual diameter growth for all biosolids treatments averaged three times higher
than for conventional fertilizer. Seasonal application differences were small
but statistically significant. All plots, including the controls, experienced
extensive top damage from snow and ice. Similar to growth, damage was greatest
with biosolids fertilization. The study shows promise for biosolids
fertilization as a viable alternative to conventional fertilization, but
application in locations prone to snow and ice damage should be avoided.
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97. Nason, G.E., D.J. Pluth, R.T. Hardin and W.B. McGill. 1990.
Dynamics of foliar N in Douglas-fir after spring and fall application of
ammonium nitrate and urea. Canadian-Journal-of-Forest-Research 20(9):
1515-1523.
Keywords: fertilization
tree physiology
Abstract:
Foliar N dynamics were studied from 1982 to 1984 after spring or autumn
application of ammonium nitrate or urea at 200 kg N/ha to an intermediate-productivity 38-yr-old Douglas fir
(Pseudotsuga menziesii) stand growing on Humo-Ferric Podzols on Vancouver Island, British Columbia.
Douglas fir responded by increasing the N concentration of existing foliage,
and both the concentration and content of N in new shoots. Six months after
spring fertilization, N concentration in current foliage averaged 30 and 21%
above that of the control for ammonium nitrate and urea, respectively. N
concentration of current foliage was increased after 2 years in the ammonium
nitrate treatment only. When ammonium nitrate was applied in autumn, peak N
concentration in current foliage occurred after 6 months (in mid-spring), at
25% above that of the control. Autumn application urea did not affect current
foliage N concentration until the next autumn, when a 19% increase over that of
the control was observed. In the first autumn after fertilization (seasons of
application combined), ammonium nitrate caused a 26% increase over control in N
content of current foliage, whereas urea caused a 13% increase. This
superiority of ammonium nitrate over urea was attributed to the nitrate ion.
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98. Nason, G.E., D.J. Pluth and W.B. McGill. 1988. Volatilization and
foliar recapture of ammonia following spring and fall application of
nitrogen-15 urea to a Douglas-fir ecosystem.
Soil-Science-Society-of-America-Journal 52(3): 821-828.
Keywords: fertilization
tree physiology
soil properties
Abstract:
Seasonal effects on the volatilization and vegetal recapture of NH3
following application of pelleted 15N urea at 200 kg N ha-1 to a 40-yr-old Douglas-fir
[Pseudotsuga menziesii] ecosystem were investigated. Volatilization totalled 14
and 0.7% of applied N in spring and autumn, respectively, and the difference
appeared to be related to precipitation patterns following fertilization.
Volatilization was generally enhanced by small spring rainfalls while depressed
by larger autumn rains. The isotopic abundance of evolved NH3 fluctuated from
>90 to <10% of that of the fertilizer source. These fluctuations
reflected the role of precipitation in the regulation of spatial heterogeneity
of urea and urease in soil. Under spring conditions NH3 was recaptured by
potted Douglas-fir seedlings. Seedlings at 10 cm above the forest floor
captured 16 times as much NH3 as seedlings positioned at the 150-cm elevation.
Labelled N was distributed among seedling tissues in the order: current foliage
> 1-year-old foliage > roots which is consistent with anabolic
incorporation and translocation. This mechanism may have a significant role in
plant nutrition when conditions favourable to NH3 volatilization follow urea
fertilization.
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99. Nelson, E.E. 1989. Black bears prefer urea-fertilized trees.
Western-Journal-of-Applied-Forestry 4(1): 13-15.
Keywords: fertilization
tree/stand
health
Abstract:
Feeding damage by the black bear (Ursus americanus) to urea-fertilized
25-yr-old Douglas fir (Pseudotsuga menziesii) in the Mount Hood National
Forest, Oregon, resulted in tree mortality 4x as
severe as among unfertilized trees. Damage was most apparent following
application of urea at 448 kg N/ha in 1972, and 224 kg N/ha in 1977. Only
Douglas fir, the dominant species in the stand, was attacked (western hemlock
(Tsuga heterophylla), western red cedar (Thuja plicata) and red alder (Alnus
rubra) were scattered through the stand). Attacked trees were somewhat larger
than the stand average but the difference was not significant. Bears appeared
to be attracted to the more vigorous trees, which were on fertilized plots.
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100. Nelson, E.E., M.G. McWilliams and W.G. Thies. 1994. Mortality and
growth of urea-fertilized Douglas-fir on a Phellinus weirii-infested site in Oregon.
Western-Journal-of-Applied-Forestry 9(2): 52-56.
Keywords: planting
operations
fertilization
tree/stand protection
growth
tree/stand health
soil properties
Abstract:
Twelve plots were established in 1972 in an 11-yr-old Douglas fir
(Pseudotsuga menziesii) plantation infected with Phellinus weirii, the cause of
laminated root rot. All plots were thinned and either interplanted with red
alder (Alnus rubra) or fertilized at 5- to 10-yr intervals with urea to
determine the effect of nitrogen on tree growth and mortality caused by P.
weirii, or left untreated. Interplanted alder, however, failed to survive.
Mortality was assessed at intervals of 2 to 3 yr. Plots were inventoried (100%
cruise) in 1978 and 1990. Growth over 12 yr appeared better on fertilized than
nonfertilized plots, but the difference was not significant. Mortality caused
by the preferential feeding of black bears [Ursus americanus] on the inner bark
of fertilized trees reduced the overall gain. Mortality caused by laminated
root rot did not differ significantly among treatments. Three months after the
initial application of urea at 448 kg N/ha, soil sampled to a depth of 30 cm
was higher in ammonium and nitrate forms of nitrogen on fertilized than
nonfertilized plots, but increases were not significant. Numbers of soil
bacteria were directly correlated with soil ammonium content (P = 0.1092).
Numbers of aerobic actinomycetes were inversely correlated with soil nitrate
content (P = 0.0398).
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101. Omule, S.A.Y. 1990. Net basal area response 9
years after fertilizing thinned and unthinned Douglas-fir. B.C. Ministry of Forests FRDA-Report 097. vi
+ 20 p.
Keywords: fertilization
thinning
growth
Abstract:
Equations were developed to estimate net basal area response of
Douglas fir (Pseudotsuga menziesii) to nitrogen (urea) fertilizer in terms of
initial stand attributes, based on remeasurement data over a 9-yr period from
176 plots on Vancouver Island, British
Columbia.
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102. Peterson, C.E. 1984. Fertilization of
Douglas-fir plantations in the Pacific Northwest RFNRP Cooperative. In
Proceedings IUFRO Symposium on Site and Productivity of Fast Growing
Plantations Volume 2, South African Forest Research Institute, Pretoria, South
Africa. Eds. D.C. Grey, A.P.G. Schonau and C.J. Schutz. pp. 637-645.
Keywords: planting
operations
fertilization
thinning
precommercial thinning
growth
Abstract:
Since 1975, the RFNRP cooperative has established 26 installations in
young widely spaced plantations of Douglas-fir for testing response to 224
kg-N/ha. These plantations ranged in breast-height age from 3 to 23 years, and
although response to fertilization was favorable in all Douglas-fir
plantations, those which were spaced to 1000 trees/ha responded significantly
better than plantations of 725 trees/ha, in both absolute and relative 2-year
basal area increment (msuperscript 2 ha-1 year-1). Response also appears to be
greater when fertilizer was applied 2 years after precommercial thinning, as
opposed to fertilizing and thinning at the same time. The relationship of
growth response with stocking level is discussed, as well as the timing of
fertilization relative to spacing, in young Douglas-fir plantations.
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103. Peterson, C.E. and J.W. Hazard. 1990. Regional variation in
growth response of coastal Douglas-fir to nitrogen fertilizer in the Pacific Northwest. Forest-Science 36(3):
625-640.
Keywords: fertilization
thinning
growth
Abstract:
Hypothesis-testing for differences in growth responses among
physiographic strata, thinning levels,
and fertilizer dosage levels resulted in a set of empirical models for
predicting the volume increment response of even-aged coastal Douglas fir
(Pseudotsuga menziesii) in W. Washington and Oregon
to N fertilizer treatment. Absolute and percentage responses are estimated for
both thinned and unthinned stands as a function of dosage levels and
physiographic provinces. Although not 'highly' significant, the physiographic
factor was retained in the models for purposes of refinement.
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104. Peterson, C.E., P.J. Ryan and S.P. Gessel. 1984. Response of
northwest Douglas-fir stands to urea: correlations with forest soil properties.
Soil-Science-Society-of-America-Journal 48(1): 162-169.
Keywords: fertilization
thinning
growth
soil properties
Abstract:
Replicated forest floor and surface soil (0-15 cm) samples were
obtained from control plots at 160 field installations in western Washington and Oregon.
Six-year growth responses of thinned and unthinned Douglas-fir [Pseudotsuga
menziesii] treated with 0, 224, and 448 of urea-N ha-1 were correlated with 18
forest floor and surface soil properties of the control plots. Forest floor nitrogen properties were the
most highly correlated with various estimates of response in both thinned and
unthinned stands; these correlations were generally independent of methods used
to estimate response. For unthinned stands, C/N ratios of both forest floor and
surface soil were well correlated with growth response to fertilizer, whereas
for thinned stands, N content (kilograms per hectare) of the forest floor was
consistently correlated with response.
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105. Prescott, C.E. 1995. Does nitrogen availability control rates of
litter decomposition in forests? Plant-and-Soil 168/169:
83-88.
Keywords: fertilization
soil properties
Abstract:
The effects of increased exogenous N availability on rates of litter
decomposition were assessed in several field fertilization trials. In a jack
pine (Pinus banksiana) forest, needle litter decomposed at the same rate in the
controls and those plots fertilized with urea and NH4NO3 at 1350 kg N/ha (+or-P
and K). Mixed needle litter of western hemlock (Tsuga heterophylla), western
red cedar (Thuja plicata), and Douglas-fir (Pseudotsuga menziesii) from plots
amended with sewage sludge (500 kg N/ha) lost less weight than the controls. Forest floor material also decomposed more
slowly after amendment with sewage sludge. Paper birch (Betula papyrifera) leaf
litter treated with either sewage sludge (1000 kg N/ha), pulp sludge, or a
sewage/pulp sludge-mixture decomposed at the same rate as the controls.
Exogenous N availability therefore had little impact on litter decomposition
rates. The influence of endogenous N availability on litter decomposition rates
was studied with a microcosm. Lodgepole pine (Pinus contorta var. latifolia)
needle litter collected from trees fertilized at 525 kg NH4NO3-N/ha and green
needles were both richer in N (1.56 and 1.9% N, resp.) than needles from
control trees (0.33 and 0.88% N, resp.), although all the needles decomposed at
the same rate. It was concluded that N availability alone, either exogenous or
endogenous, did not control litter decomposition rates. Increased N
availability, through fertilization or deposition, in the absence of changes in
vegetation composition, was not considered sufficient to alter rates of litter
decomposition in forests.
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106. Prescott, C.E., L.P. Coward, G.F. Weetman and S.P. Gessel. 1993a. Effects of repeated nitrogen fertilization on the ericaceous
shrub, salal (Gaultheria shallon), in two coastal Douglas-fir forests.
Forest-Ecology-and-Management 61(1-2): 45-60.
Keywords: fertilization
growth
stand conditions
Abstract:
Understorey vegetation changes were quantified following nitrogen fertilizer
trials at two sites in the Pacific
Northwest. In the Pack Forest, Washington, USA, -
second growth (70-yr-old) Douglas fir (Pseudotsuga menziesii) - salal
(Gaultheria shallon) was eliminated in a plot that had been fertilized with
nitrogen alone (1540 kg N/ha as ammonium nitrate and urea between 1950 and
1982), but was unchanged in a plot that received phosphorus and sulfur in
addition to nitrogen (1082 kg N/ha). In a trial near Parksville, Vancouver
Island - logged in 1947, stand comprising 75% Douglas fir, site index 33 m at
age 50 yr - salal cover was reduced with increasing amounts of nitrogen, and
was eliminated in plots that received 600 kg N/ha as urea in three
applications. Reductions were less pronounced in plots that received sulphur in
addition to nitrogen. In the Pack Forest
trial, the cover of snowberry (Symphoricarpos albus) increased in the plot
where salal was eliminated; in the Parksville trial, no other species became
more abundant in the absence of salal. Tree stem volume and stem volume
increment in each plot were not related to salal cover in the plots. Results
suggest that high concentrations of ammonium and nitrate in the forest floors
of N-fertilized plots may render salal less competitive, or may interfere with
ericoid mycorrhizae, contributing to reduced cover of salal in forests
receiving repeated N-applications.
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107. Prescott, C.E., M.A. McDonald, S.P. Gessel and J.P. Kimmins. 1993b. Long-term effects of sewage sludge and inorganic fertilizers
on nutrient turnover in litter in a coastal Douglas fir forest.
Forest-Ecology-and-Management 59(1-2): 149-164.
Keywords: fertilization
soil properties
Abstract:
Rates of litter input, decomposition, net N mineralization, and N and
P supply on the forest floor were measured in a 70-yr-old second growth stand of
Douglas fir (Pseudotsuga menziesii) on a poor site in western Washington
state, approximately 10 yr
after applications of sewage sludge and inorganic fertilizers. Sewage sludge
was applied to three plots at the rate of 6000 kg N/ha, and nitrogenous fertilizers
were applied to two plots at rates of 1082 and 1568 kg N/ha. The rate of each
process in each treated plot was compared with that in an adjacent control
plot. Amounts of N returned in needle litter during 1 yr were greater on
sludged and fertilized plots relative to adjacent control plots. Decomposition
of a standard needle litter was the same on all plots after a 2-h in situ
incubation. Rates of N mineralization during aerobic incubations of forest
floor material were similar in all plots in field incubations, but smaller
rates were measured in material from sludged plots in laboratory incubations.
Greenhouse bioassays with Douglas fir and Sitka
spruce (Picea sitchensis) seedlings showed greater P supply in forest floor
material from sludged plots, but no differences in N supply between any
treatments. Turnover of N in litter was not different 10 yr after fertilization
of this forest with sewage sludge or N fertilizer. There was evidence of
long-term enhancement of P turnover in litter plots treated with sewage sludge.
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108. Prescott, C.E. and L.M. Zabek. 1999. Decomposition and nitrogen
mineralization in forests of British Columbia:
effects of forest management practices. In
Proceedings: Pacific Northwest forest and
rangeland soil organism symposium; 1998 March 17-19; Corvallis, OR.
Pacific-Northwest-Research-Station,
USDA-Forest-Service General-Technical-Report PNW-GTR-461. Eds. R.T.
Meurisse, W.G. Ypsilantis, and C. Seybold. 124-136 pp.
Keywords: planting
operations
fertilization
soil properties
Abstract:
The productivity of most forests in the Pacific Northwest is limited by the
availability of nitrogen. Nitrogen availability is largely controlled by the
rate at which N is recycled from organic matter, through the processes of decomposition
and mineralization. These processes are controlled by the factors that limit
the activities of the soil organisms involved, particularly temperature,
moisture, and the physical and chemical nature of the organic matter. Forest management activities may influence
each of these factors and thereby affect rates of decomposition, N
mineralization and N availability. The influences of several common forest
management activities on decomposition and N mineralization were examined in a
suite of experiments across British Columbia, Canada.
Rates of decomposition were compared in forests and adjacent clear felled areas
at 22 sites, and rates were either the same or slower in the felled areas.
Several sites had additional silvicultural treatments that provide a range of
either opening size or removal intensity. Decomposition rates were not
influenced by opening size, but rates of net N mineralization and nitrification
were increased in openings greater than 0.1 ha. Tree species influences N
mineralization in the forest floor, with highest rates occurring in Douglas-fir
and broadleaf species and lowest rates in cedar and pines. The decomposition rates of foliar litters was best
predicted by its lignin concentration. The influence of managing to maintain a
component of broadleaf species was examined in decomposition experiments with
pure and mixed litter of aspen and spruce, Douglas-fir and alder, and lodgepole
pine, Douglas-fir and paper birch. There was no effect of mixing litters on
their rates of decomposition. Likewise, N fertilization had no effect on
decomposition rates in trials in coastal Douglas-fir and aspen.
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109. Preston,
C.M., V.G. Marshall, K. McCullough and P.J. Mead. 1990. Fate of 15N-labelled
fertilizer applied on snow at two forest sites in British Columbia.
Canadian-Journal-of-Forest-Research 20(10): 1583-1592.
Keywords: fertilization
soil properties
Abstract:
Fertilizer was applied on snow in January 1981 at 100 kg N/ha as
(15N)urea, 15NH4NO3 or NH415NO3 to 11-yr-old lodgepole pine (Pinus contorta
var. latifolia) at Spillimacheen in the British Columbia interior and as
(15N)urea (200 kg N/ha) to 13-yr-old Douglas fir (Pseudotsuga menziesii) at
Green Mountain, a coastal site in British Columbia. Recovery of labelled N
after one growing season was determined in soil and biomass at both sites, and
it was also monitored during the growing season in snow and soil at
Spillimacheen. At Green Mountain,
5.5% of urea N was recovered in tree biomass, 10.8% in understorey and 33.4% in
soil organic N (total recovery 49.7%). Leaching may have contributed to N
losses at Green Mountain,
but was probably not a direct consequence of the application on snow. At
Spillimacheen, total recovery of (15N)urea
was 93.3%, with 10.1% in tree biomass, 2.4% in understorey and 80.8% in soil.
For 15NH4NO3, recoveries were 5.3% in tree biomass, 2.9% in understorey and
87.0% in soil, for a total of 95.2%. For NH415NO3, recoveries were 1.9% in tree
biomass, 3.4% in understorey and 39.1% in soil, for a total of 44.4%. At
Spillimacheen, the performance of 15NH4NO3 was comparable to that of urea in
tree uptake and soil retention. There were large losses with the NH415NO3
source, however, probably because of leaching and denitrification during
snowmelt. For this reason, fertilization with nitrate on snow is not
recommended because of nitrate's susceptibility to leaching, but urea and
ammonium sources may be applied under these conditions.
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110. Preston,
C.M. and R.H. Newman. 1995. A long-term effect of N fertilization on the 13C
CPMAS NMR of de-ashed soil humin in second-growth Douglas-fir stand of coastal British Columbia.
Geoderma 68(4): 229-241.
Keywords: fertilization
thinning
soil properties
Abstract:
Carbon-13 CPMAS NMR spectroscopy was used to examine long-term effects
of thinning and N fertilization on the humin fraction of soil organic matter in
a second-growth Douglas-fir (Pseudotsuga menziesii) stand in coastal British Columbia, Canada.
De-ashed OM-enriched humin fractions were prepared from three mineral soil
horizons of four silvicultural treatments using 1.0M HF accompanied by removal
of ferromagnetic iron particles, and a density separation. With some exceptions
a higher proportion of mass was recovered in the denser, light-coloured
fraction, and a higher proportion of C and N in the less-dense, dark fraction.
In all cases, the less-dense fraction was enriched in total C compared to the
original crude humin, and had a more favourable C:Fe ratio for NMR spectroscopy. The fraction of
observable C was 33-37% for 8 of the samples, but as low as 7.6% for the
remaining four. Carbon-13 CPMAS NMR spectra had typical features for humins
(alkyl C, O-alkyl C, di-O-alkyl C, aromatic C, and carboxyl, ester and amide
C). With fertilization, there was a small but consistent decrease in the ratio
of alkyl to O-alkyl C, regardless of horizon or thinning, indicating a lower extent
of decomposition. Carbon-13 subspectra based on proton spin relaxation time (T1(1H)) were obtained for one
fertilized and one unfertilized sample. Subspectra of the slowly-relaxing (long
T1(1H)) domain were dominated
by long-chain alkyl C. For the fertilized sample, the subspectrum of the
fast-relaxing (short T1(1H))
domain had a higher proportion of O- and di-O-alkyl C, consistent with results
from the normal CPMAS NMR spectra. Despite the uncertainties introduced by the
de-ashing treatment and the low fraction of observable C, 13C CPMAS NMR showed
that fertilization has a long-term effect which is reflected in this humin
fraction.
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111. Prietzel, J., G.L. Wagoner and R.B. Harrison. 2004. Long-term
effects of repeated urea fertilization in Douglas-fir stands on forest floor
nitrogen pools and nitrogen mineralization. Forest-Ecology-and-Management
193(3): 413-426.
Keywords: fertilization
soil properties
Abstract:
In six Douglas-fir [Pseudotsuga menziesii
(Mirb.) Franco] stands in the Puget Sound Region in Western Washington/USA,
forest floor C and N pools were quantified on control plots and on plots that
had been fertilized repeatedly with urea 8-30 years ago (total amount of
applied N 0.9-1.1 Mg ha-1). Additionally, net N mineralization and
nitrification rates were assessed in field and laboratory incubation
experiments. Forest
floor C/N ratios were decreased on the fertilized plots of all sites compared
to the respective control plots. The decreases were particularly strong at
sites with initial C/N ratios larger than 30. On sites with low productivity
(site index at age 50: <33 m), N fertilization resulted in considerable
increases in forest floor N pools. Net N mineralization and nitrification
during 12-week field incubation was negligible for the unfertilized and
fertilized plots of all except one site (Pack Forest),
where the stand had been clear-cut 2 years ago. The increases in N
mineralization rates during 12-week laboratory incubation induced by repeated N
fertilization showed an inverse relationship to the time elapsed since the last
fertilizer application, and were generally larger at sites with initial forest
floor C/N ratios >30. For the investigated sites, fertilization effects on
net N mineralization sustained for at least 11 years after the last fertilizer
application. Nitrification correlated strongly with the forest floor pH;
significant formation of NO3- was observed only for O layers with a pH (H2O)
higher than 4.5.
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112. Radwan, M.A. and J.S. Shumway. 1984. Site index and
selected soil properties in relation to response of Douglas-fir and western
hemlock to nitrogen fertilizer. In Forest soils and treatment impacts:
Proceedings of the Sixth North American Forest Soils Conference, Department of
Forestry, Wildlife and Fisheries, University of Tennessee, Knoxville, TN, June
1983. Ed. E.L. Stone. pp. 89-104.
Keywords: fertilization
growth
soil properties
Abstract:
Studies were made in 25 Douglas fir stands in Washington and Oregon and in 16 western hemlock
stands in Washington. Site
index, total and mineralizable soil N were the only variables correlated with
growth response to N fertilizer by Douglas fir. Growth response of hemlock was
correlated with extractable P/total N in the soil. Total N and mineralizable S
in mineral soil were highly correlated and showed moderate negative
correlations with growth response of hemlock, but site index was not correlated
with response. Results suggest that site index and soil N seem promising
indicators of the response of Douglas fir to N fertilizer, while extractable P
and the P/N ratio may indicate the response of hemlock. Soil N appears to be
more important than soil P in predicting the response of Douglas fir on the sites
studied. Soil S did not appear to limit the response of either species to N
fertilizer and does not seem promising for estimating the response to N.
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113. Radwan, M.A., J.S. Shumway, D.S. DeBell and J.M. Kraft. 1991.
Variance in response of pole-size trees and seedlings of Douglas-fir and
western hemlock to nitrogen and phosphorus fertilizers.
Canadian-Journal-of-Forest-Research 21(10): 1431-1438.
Keywords: nursery
operations
nursery fertilization
fertilization
tree physiology
growth
Abstract:
A study was made of the effects of N, P and NP fertilizer treatments
on plant nutrients and growth of Douglas fir (Pseudotsuga menziesii) and
western hemlock (Tsuga heterophylla). Three trials were conducted, (1) and (2)
on pole-size trees at two different sites in Washington
and (3) on potted seedlings in a lathhouse; only T. heterophylla was studied in
(2). Soil series were Bunker for Douglas fir and Klone for western hemlock in
trials 1 and 3, and Vesta in trial 2. Nitrogen fertilizers used were urea in
trial 1 and ammonium nitrate in the other two trials; P was applied as triple
superphosphate in all three trials. For each species in trial (1), P was
applied at 0, 100, 300 and 500 kg P/ha and N was applied at 0 and 224 kg N/ha
in a factorial design. In trial (2), P was applied at 0, 100 and 300 kg P/ha
and N was applied at 0 and 112 kg N/ha in a factorial design. In trial (3), N
and P were applied individually to seedlings at a rate of 100 kg N/ha and 226
kg P/ha. In general, fertilizer treatments changed the levels of some
plant-tissue nutrients of the pole-size trees and potted seedlings. Neither
height nor basal area growth of the trees were significantly affected by any of
the treatments in the first two trials. Seedling growth of both Douglas fir and
western hemlock was improved by P fertilizer, but was negatively affected by N
fertilizer. The results clearly show differences between pole-size trees and
seedlings in response to N and P fertilizers. It is concluded that N should not
be applied where soils are high in N and low in P, and that P applications
should be confined to sites with low-P soils, when trees are young, before
canopy closure.
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114. Rollwagen, B.A. 1983. Effects
of ammonium and nitrate application on rhizosphere pH, growth and nutrient
uptake by Douglas-fir, Sitka
spruce and western hemlock. Forestry-Abstracts 44(11): 699.
Keywords: fertilization
soil properties
growth
tree physiology
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115. Rose, R., M. Atkinson, J. Gleason and T. Sabin. 1991. Root volume
as a grading criterion to improve field performance of Douglas fir seedlings.
New-Forests 5(3): 195-209.
Keywords: nursery
operations
fertilization
tree/stand health
growth
Abstract:
Three Oregon seed sources of Douglas fir (Pseudotsuga menziesii) were
grown as 2+0 bare-root seedlings, and graded into three root-volume categories
(<9, 9-13, and >13 cmsuperscript 3) before outplanting in Columbia
County, Oregon in January 1987. The following were assessed: (1) differences in
survival and growth after one and two growing seasons in the field; (2)
relation(s) of seedling height after one and two seasons to preplanting nursery
root volume, total fresh weight, root-collar diameter, and height; and (3)
differences in field performance due to application of NPK fertilizer at
planting. Field survival was >90% among all root-volume categories.
Seedlings in the largest category grew significantly better than those in the
two smaller categories over two seasons. Fertilization at time of planting had
no effect on survival or growth because of shallow placement (3 cm below soil
surface) of the fertilizer pellet. The results suggest that using root volume
as well as height and diameter as a seedling grading parameter is worthwhile where
morphological quality must be maximized to improve field performance.
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116. Rose, R. and J.S. Ketchum. 1998. Early results of the 'Herb II'
study: evaluating the influence vegetation control has on fertilization at the
time of planting. In Proceedings of the Annual Meeting of the Western
Society of Weed Science, Waikoloa, Hawaii, 10-12 March, 1998. pp. 55-59.
Keywords: release
treatments
chemical release
fertilization
growth
Abstract:
Field trials were conducted at 5 sites in the Pacific Northwest region of the
USA to assess the interactive effects between increasing levels of control of
deerbrush (Ceanothus integerrimus), snowbrush (C. velutinus), black cottonwood
(Populus trichocarpa), Scotch broom (Cytisus scoparius), Portuguese broom (C.
striatus), trailing blackberry (Rubus sp.), thimbleberry (R. parviflorus) and
salmonberry (R. spectabilis) with hexazinone or sulfometuron, and fertilizer
treatments using slow release briquettes of N:P:K at 14:3:3 or 9:9:4 applied at
planting for Douglas fir (Pseudotsuga menziesii), ponderosa pine (Pinus
ponderosa), western hemlock (Tsuga heterophylla) and coastal redwood (Sequoia
sempervirens). Results indicated that at all but one site, weed control +or-
fertilizer led to increased tree growth, while at the fifth site weed control +
fertilizer gave the greatest growth. Fertilizer alone did not increase growth
at any site.
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117. Rose, R. and J.S. Ketchum. 2002. Interaction of vegetation
control and fertilization on conifer species across the Pacific Northwest.
Canadian-Journal-of-Forest-Research 32(1): 136-152.
Keywords: fertilization
release treatments
chemical release
growth
tree/stand health
tree physiology
stand conditions
Abstract:
An experiment evaluating three levels of vegetation competition
control (no control, 1.5 m2 of vegetation control, and 3.3 m2 of vegetation
control), each with two fertilizer application treatments (fertilizer
application at the time of planting with complete slow-release fertilizer
(WoodaceReg. IBDU), or no fertilizer application), was installed at five sites.
Two of these sites were planted with Douglas-fir (Pseudotsuga menziesii) in the
Oregon Coast Range, one with ponderosa pine (Pinus ponderosa) in eastern
Washington, one with western hemlock (Tsuga heterophylla) in the coastal
hemlock zone in Oregon, and one with coastal redwood (Sequoia sempervirens) in
northern California, USA. At four of the five sites, mean stem volume, basal
diameter, and height of seedlings increased significantly with increasing area
of weed control, and the magnitude of difference between treatments increased
with time. Fertilizer application significantly increased seedling size only at
the two sites with adequate soil moisture; increases were marginally
significant at a third. Response to fertilizer application was less than from
weed control and impacted growth for only the first year, whereas the influence
of weed control continued to influence growth the entire length of the study (4
years). Area of vegetation control and fertilizer application did not interact
significantly at any site.
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118. Rose, R. and J.S. Ketchum. 2003. Interaction of initial seedling
diameter, fertilization and weed control on Douglas-fir growth over the first
four years after planting. Annals-of-Forest-Science 60(7): 625-635.
Keywords: nursery
operations
fertilization
release treatments
chemical release
growth
tree/stand health
stand conditions
Abstract:
Planting larger stock, fertilizer application and added years of weed control
are often employed to increase growth rate of plantations. We evaluated these
techniques using a replicated factorial study design repeated in two diverse
locations in western Washington State, USA.
Two different sizes of planting stock, NPK fertilizer application at planting
and in the following year, and two or three years of weed control using
herbicides were tested. No significant interactions among the treatment levels
were found with all treatments influencing Douglas-fir (Pseudotsuga menziesii)
growth in an additive manner. Fourth year stem volume gains were greatest from
planting larger initial stock: planting seedlings 2 mm larger in basal diameter
resulted in fourth-year stem volume gains of 35 and 43%. The fertilizer
application treatments used produced early gains, but they were short lived.
The third-year weed control treatment had no observable effect on fourth-year
stem volume or on volume growth in years three or four.
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119. Rosso, P. and E. Hansen. 1998. Tree vigour and the susceptibility
of Douglas fir to Armillaria root disease. European-Journal-of-Forest-Pathology
28(1): 43-52.
Keywords: fertilization
thinning
pruning
tree/stand protection
growth
tree/stand health
carbon allocation
Abstract:
The effects of thinning, fertilization and pruning on the vigour of Douglas
fir (Pseudotsuga menziesii) and its susceptibility to Armillaria root disease
were investigated in Oregon, USA.
Tree vigour was defined as the relative capacity for tree growth, expressed as
the above-ground biomass increment per unit of photosynthetic tissue, or growth
efficiency (GE). It has been hypothesized that trees with higher GE can better
resist pathogen attack, and that GE can be used as a predictor of tree
susceptibility to disease. In a previous study, four P. menziesii plantations
were thinned, fertilized and pruned in all combinations, and the effects of
these treatments on tree vigour were measured after 10 years. Root disease was
not a factor in the initial study design, and mortality was ignored until 8
years after the treatments were applied. The results of an earlier study were
utilized and the correlation between Armillaria root disease incidence and the
effects of earlier stand treatments on tree growth was investigated. A. ostoyae
[A. obscura] was the primary cause of mortality in the study area. The disease
incidence of infected subplots ranged from 2 to 20%. A. obscura incidence was
the highest at medium tree density (6.1%), slightly lower on the low density
(5.6%) and lowest on the unthinned plots (3.8%). There were no significant
correlations between disease incidence and previous tree growth. The vigour of
trees that became symptomatic or died by 1993 was not significantly different
from the vigour of trees that remained asymptomatic in 1983-85. On these sites,
in areas of infection, A. obscura was causing mortality of the largest, fastest
growing trees, as well as less vigorous trees. It is concluded that Armillaria
continues to cause mortality, regardless of the growth efficiency or growth
rate of the host.
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120. Roth, B.E. and M. Newton. 1996a. Role of Lammas
growth in recovery of Douglas-fir seedlings from deer browsing, as influenced
by weed control, fertilization, and seed source.
Canadian-Journal-of-Forest-Research 26(6): 936-944.
Keywords: planting
operations
release treatments
chemical release
fertilization
tree/stand protection
growth
tree/stand health
Abstract:
This study examined the effects of weed control, nitrogen fertilizer,
and seed source on Lammas growth (second flushing) in Douglas fir (Pseudotsuga
menziesii) seedlings on 3 sites in the Oregon Coast Range.
It also assessed the occurrence of deer (Odocoileus hemionus columbianus)
browsing as related to these silvicultural treatments and examined the role of
Lammas growth in seedling recovery and escape from deer browsing. Seedlings
(averaging 54 cm tall, 6 mm diameter at 15 cm above ground) were planted in
February 1992, and measured at the time of planting and in autumn 1992 and
1993. Complete weed control with hexazinone (annual applications + spot
treatments as necessary) significantly increased the occurrence of Lammas
growth. Nitrogen fertilizer (220 kg/ha urea) decreased Lammas growth
significantly, at least in part by favouring weed growth. Lammas growth was not
influenced by seed source (genetically improved from a seed orchard or local
wild stock). The increased Lammas growth associated with weed control mediated
the effects of deer browsing. Although multiple-year browsing occurred more
commonly on weeded than unweeded seedlings, after two growing seasons weeded
seedlings that were repeatedly browsed were twice as large as unbrowsed,
unweeded seedlings. On one site, stock of wild origin was more heavily browsed
than that from a seed orchard.
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121. Roth, B.E. and M. Newton. 1996b. Survival and
growth of Douglas-fir relating to weeding, fertilization, and seed source.
Western-Journal-of-Applied-Forestry 11(2): 62-69.
Keywords: planting
operations
fertilization
release treatments
chemical release
growth
tree physiology
tree morphology
tree/stand health
Abstract:
The goal of this study was to quantitatively evaluate the individual
and interactive effects of weed control, nitrogen fertilizer, and seed source
on Douglas fir (Pseudotsuga menziesii) survival and growth in plantations on a
range of sites and growing conditions in western Oregon.
Weed control with hexazinone (broadcast application after planting) was the
dominant factor influencing seedling survival and growth and accounted for 49%
of the explained variation in seedling volume after 2 years. Nitrogen
fertilizer (urea) had no effect when used in conjunction with weed control and
a negative effect when used without weed control. Seedlings from a seed orchard
source were significantly larger in diameter and volume than those from a wild
local source after two growing seasons, but second-year heights were similar
for the two seedling types. Initial seedling size was positively correlated
with growth rate.
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122. Sachs, D. and J.A. Trofymow. 1991. Testing the performance of
FORCYTE-11 against results from the Shawnigan Lake
thinning and fertilization trials on Douglas-fir. Canadian-Forest-Service, Pacific and Yukon
Region Information-Report BC-X-324. viii + 58 p.
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 British Columbia.
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123. Shumway, J.S. and H.N. Chappell. 1995. Preliminary DRIS norms for
coastal Douglas-fir soils in Washington and Oregon.
Canadian-Journal-of-Forest-Research 25(2): 208-214.
Keywords: fertilization
thinning
growth
soil properties
Abstract:
The Diagnosis and Recommendation Integrated System (DRIS) has been
used successfully to evaluate interactions between nutrients and fertilizer
response and for diagnosing nutrient deficiency in agricultural crops. This
study used soil tests to develop DRIS norms and evaluate their effectiveness in
coastal Douglas fir (Pseudotsuga menziesii) forests. DRIS norms for nitrogen,
phosphorus, potassium, and calcium were developed using soil test and site
index data from 72 soil series that commonly support Douglas fir in western Washington.
The norms were tested using soil test and stand basal area growth response data
from 20 thinned and 30 unthinned N fertilizer test sites in coastal Washington and Oregon.
Response to urea fertilizer in thinned stands averaged 34% and 43% for 224 and
448 kg N.ha-1, respectively, when N was identified as the most limiting
nutrient. When N was not the most limiting nutrient, N response averaged 8% and
10% for 224 and 448 kg N.ha-1, respectively. Results were similar in unthinned
stands and thinned stands, although response to fertilizer appeared to be
slightly less in unthinned stands when N was the most limiting nutrient. DRIS correctly
classified 25 of the 33 sites (76%) where N fertilizer increased growth by more
than 15%. More importantly, 13 of the 17 (76%) sites that responded by less
than 15% were correctly identified by DRIS. The results clearly indicate that N
fertilizer response is dependent on the interactions (balance) between soil
nutrients at a given site. Future soil diagnostic work needs to focus on
techniques, like DRIS, that provide an assessment of these interactions.
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124. 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.
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125. Stegemoeller, K.A. and H.N. Chappell. 1990. Growth response of
unthinned and thinned Douglas-fir stands to single and multiple applications of
nitrogen. Canadian-Journal-of-Forest-Research 20(3): 343-349.
Keywords: fertilization
thinning
growth
Abstract:
Basal area and volume growth response of unthinned and thinned Douglas
fir (Pseudotsuga menziesii) stands to single and multiple applications of N
fertilizer (as urea) were estimated for eight 2-yr periods in second-growth
stands in Washington
and Oregon. Response
estimates, as differences between growth rates on fertilized and control plots
after adjusting for initial volume (or basal area), and trends, were analysed
on a regional scale. Average responses to the initial fertilization and to both
the second and third fertilizer applications, 8 and 12 yr later, were
statistically significant (P <0.05). In thinned stands, average duration of
response to the initial treatment was approximately 8 yr; unthinned stands
continued to show significant volume growth response through 14 yr although
basal area growth response decreased to nonsignificant levels between years 10
and 12. In both cases, the response to refertilization, while significant, was
smaller than the response to the initial fertilization. N applied after the 8th
yr and a refertilization after the 12th, on one initially untreated plot at
each site, also produced significant average growth responses.
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126. Stegemoeller, K.A. and H.N. Chappell. 1991. Effects of
fertilization and thinning on 8-year growth responses of second-growth Douglas
fir stands. Canadian-Journal-of-Forest-Research 21(4): 516-521.
Keywords: fertilization
thinning
growth
Abstract:
An evaluation is presented of a regional research project on basal area and
volume increment responses to fertilizer (N) and fertilizer with thinning
treatments of Pseudotsuga menziesii in W. Washington
and Oregon for four
2-year measurement periods. Fertilization generally increased both basal area
and volume growth for at least 8 years. Thinning tended to have an even greater
effect than fertilization on basal area and volume growth on an individual-tree
basis. Overall, however, the removal of growing stock by thinning caused volume
growth to be less than that of the control. The magnitude and duration of this
negative response was dependent on the level of thinning and on site quality. A
significant positive interaction between fertilization and thinning exists. The
combined treatment resulted in the greatest absolute basal area and volume
increments, and the response became greater than that to fertilizer alone in
the 3rd and 4th years, and remained so for at least 8 years.
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127. Strader, R.H. and D. Binkley. 1989. Mineralization and
immobilization of soil nitrogen in two Douglas-fir stands 15 and 22 years after
nitrogen fertilization. Canadian-Journal-of-Forest-Research 19(6): 798-801.
Keywords: fertilization
growth
soil properties
Abstract:
Additions of 15N-labelled NH4Cl were used to examine the role of
microbial immobilization in long-term growth response of Douglas fir
(Pseudotsuga menziesii) plantations to N fertilizer treatment. Soil samples
were collected in summer 1986 from fertilized (448 or 470 kg/ha N) and
nonfertilized plots at previously established N fertilization experiments near
Shawnigan Lake, British Columbia, and the Wind River Experimental Forest near
Carson, Washington. Douglas fir on these sites were reported to still be responding to N
fertilization after 12 and 18 years. Less than 2% of the added 15N was
recovered as mineral N after a 14-day laboratory incubation of soil samples
from the fertilized and nonfertilized plots. This indicates that gross mineralization
could be >50x greater than net mineralization in these infertile soils if
the remaining 98% of the added 15N were all biologically immobilized. Net
mineralization was significantly greater (p <less or =>0.10) in soils
from the fertilized plots than in those from the nonfertilized plots at the Wind River site. Although the current
differences in N availability did not appear to be related to differences in
microbial immobilization, such large rates of immobilization require further
investigation as a factor in long-term response to fertilization.
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128. Strand,
R.F. and D.S. DeBell. 1981. Growth response to fertilization in relation to
stocking levels of Douglas-fir. In Proceedings: Forest
Fertilization Conference, University of Washington, Seattle, Washington,
USA.
Eds. S.P. Gessel, R.M. Kenady and W.A.
Atkinson. pp. 102-106.
Keywords: planting
operations
fertilization
thinning
growth
Abstract:
Growing stock levels affect the response of Douglas-fir stands to applications
of nitrogen fertilizer. Response is maximum
at intermediate stocking levels, and is less at higher or lower levels of stand
density. Nitrogen fertilization accelerates growth and therefore increases the
rate of buildup of stand density. Thinnings will be required to reduce stocking
to appropriate levels if good responses to repeated nitrogen applications
throughout a rotation are to be obtained.
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129. 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.
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130. Tesch, S.D.,
G.M. Filip, S.A. Fitzgerald and D.D. Marshall. 1994. Silvicultural treatments
for enhancing tree value, vigor, and growth in 70- to 120-year-old stands
dominated by noble fir on the Warm Springs Indian Reservation: a synthesis of
the literature. Forest Research Laboratory, College of Forestry, Oregon
State University. iii + 21 p.
Keywords: fertilization
thinning
pruning
tree/stand protection
growth
yield
tree/stand health
Abstract:
The Warm Springs Indian Reservation, Oregon,
apparently contains some 30 000 acres of naturally regenerated, largely
unmanaged stands of 70- to 120-year-old mixed conifer forest dominated by noble
fir (Abies procera), with Douglas-fir [Pseudotsuga menziesii], and some Pacific
silver fir [Abies amabilis] and western hemlock [Tsuga heterophylla]. The
synthesis focuses on growth and yield, thinning, pruning, fertilizer treatment,
disease, minimizing stand damage during thinning, and insect pests.
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131. Thies, W.G. and E.E. Nelson. 1988. Bulldozing stumps and nitrogen
fertilization affect growth of Douglas-fir seedlings.
Canadian-Journal-of-Forest-Research 18(6): 803-806.
Keywords: site
preparation
mechanical preparation
fertilization
growth
Abstract:
Eight treatments involving stump removal (either all stumps removed or
the plot left undisturbed) and broadcast application of ammonium nitrate (N at
0, 336, 672 or 1345 kg/ha) were applied to 0.04-ha circular plots in a clear
felling on the Olympic Peninsula, Washington. Pseudotsuga menziesii seedlings
were planted several months after treatment; d.b.h. and height were recorded 5
and 8 yr after planting. Results showed that either bulldozing stumps or
application of nitrogen increased seedling growth. After 8 yr, bulldozing had
increased seedling height and d.b.h. by 23 and 43%, respectively; increases
caused by nitrogen fertilizer were 13 and 17%, respectively.
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132. Thies, W.G., E.E. Nelson and D. Zabowski. 1994. Removal of stumps
from a Phellinus weirii infested site and fertilization affect mortality and
growth of planted Douglas-fir. Canadian-Journal-of-Forest-Research 24(2):
234-239.
Keywords: site
preparation
mechanical preparation
fertilization
tree/stand protection
tree/stand health
growth
soil properties
Abstract:
A field study was established in a 4.9 ha clearcut on the west slope
of the Cascade Range (44 degrees 21'N, 122 degrees 39'W), Oregon, to evaluate
the effects of stump removal (of both infested and non-infested stumps) and fertilizing
with ammonium nitrate on the incidence of laminated root rot (caused by
Phellinus weirii) in Douglas fir (Pseudotsuga menziesii) seedlings. A 2x4 set
of factorial treatments of stump removal in combination with nitrogen
fertilizing was applied in August 1980 to 0.04-ha circular plots within the
clearcut. Treatments included stump removal (either all stumps removed or the
plot left undisturbed) and broadcast application of ammonium nitrate (0, 336,
672, or 1345 kg N/ha). Diameter at breast height and height of Douglas fir,
planted as 2+1 bare root seedlings 4 months after treatment (in January 1981),
were recorded 5 and 9 seasons after outplanting. Soil bulk density in the upper
20 cm was measured with a single-probe neutron densimeter. Stump removal
reduced the number of seedlings killed by laminated root rot but had no
significant effect on seedling growth. Stump removal increased soil bulk
density only 7% as measured 9.7 years after treatment. Fertilizer increased the
growth in diameter at breast height, and height growth of the seedlings but had
no effect on mortality. There were no significant interactions between
fertilizing and stumping treatments. Increased total soil N could still be
detected on fertilized, nonstumped plots 9.7 years after treatment.
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133. Thies, W.G. and R.N. Sturrock. 1995. Laminated root rot in Western North America. Pacific Northwest Research Station, USDA Forest
Service General Technical Report GTR-PNW-349. iv + 32 pp. p.
Keywords: planting
operations
site preparation
mechanical preparation
fertilization
thinning
tree/stand protection
tree/stand health
Abstract:
Laminated root rot, caused by Phellinus weirii, is a serious root disease
affecting Douglas fir (Pseudotsuga menziesii) and other commercially important
species of conifers in northwestern North
America. This report gives an overview of the disease
as it occurs in the Pacific Northwest in Canada and the USA.
Information on recognizing crown symptoms and signs of the disease is
presented. The disease cycle of laminated root rot, from initiation to
intensification and distribution within infected stands, is described. Finally,
disease management strategies during stand development and at stand regeneration
are discussed. Features on the nomenclature of the fungus and on its management
by silvicultural and mechanical approaches also are included.
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134. Thomson, A.J. and H.J. Barclay. 1984. Effects of thinning and
urea fertilization on the distribution of area increment along the boles of
Douglas-fir at Shawnigan Lake, British
Columbia.
Canadian-Journal-of-Forest-Research 14(6): 879-884.
Keywords: fertilization
thinning
tree morphology
growth
Abstract:
Assessments were made using radial growth measurements made 6 and 9 yr
after treatment. Within treatments, av. area increment per tree was linearly related
to d.b.h. and this relation was used to evaluate the effects of treatment on
growth rate. Fertilizing had the greatest effect on av. area increment, and for
a particular fertilization regime, thinning increased the response. Thinning
modified the distribution of growth over the bole of all trees and increased
butt flare, especially in smaller trees. The effect declined from the 4- to
6-yr measurement period to the 7- to 9-yr measurement period. Fertilizing had
no consistent effect on growth distribution. The regression methods used in
this study provided a more sensitive measure of form changes than previous
methods, were independent of size distribution, and facilitated extrapolations
and evaluation of temporal trends.
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135. Thomson, A.J., K.D. Tudor, V.J. Korelus and D.R. Ralph. 1988.
Detecting the response of Douglas-fir to nitrogen fertilization by regression
of periodic annual basal area increment against basal area.
Canadian-Journal-of-Forest-Research 18(10): 1343-1346.
Keywords: fertilization
growth
Abstract:
Douglas-fir (Pseudotsuga menziesii) b.a. response to urea application at 112 and 224 kg
N/ha was studied on a medium site on Vancouver Island, British
Columbia. Regression of tree
periodic annual b.a. increment
against b.a. was used to estimate within-plot growth rates. Higher growth rates
were observed in the plots treated with fertilizer. The slope coefficients of
the regressions were used to investigate spatial and temporal variation in
growth rates.
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136. Trofymow, J.A., H.J. Barclay and K.M. McCullough. 1991. Annual
rates and elemental concentrations of litter fall in thinned and fertilized
Douglas-fir. Canadian-Journal-of-Forest-Research 21(11): 1601-1615.
Keywords: fertilization
thinning
soil properties
Abstract:
Overstorey litterfall (primarily needles) was collected for 15 years
(1972-86) within control and treated plots in a Douglas fir (Pseudotsuga
menziesii) stand near Shawnigan Lake, British
Columbia. Treated plots were
thinned or fertilized, or both. Thinned plots had two-thirds of their basal
area removed; fertilized plots were treated with 448 kg N/ha of either urea or
ammonium nitrate, and the
fertilized plots were refertilized at the same rate 9 years later. The annual
rate of litterfall in control plots averaged 1890 kg/ha. In control plots,
significant yearly variations were observed in litterfall mass and
concentrations of K, Mg, and Ca but not N or P. Thinning decreased rates of
litterfall by 80%, but rates returned to control-plot levels after 13-15 years
in unfertilized plots and after 8-10 years in fertilized plots. Fertilizer
treatment without thinning depressed litterfall in the year of treatment but
increased the rate by 20-80% in subsequent years. Litterfall N concentrations
increased by 40-80% the year of fertilizer treatment and then began decreasing
3-6 years later. Nitrogen fertilization reduced litterfall P, K and Mg
concentrations for 8, 4 and 1 year(s), respectively, following fertilizer treatment.
The effects were greater in ammonium nitrate plots than in urea plots. Rates of
litterfall correlated poorly with stand density but well with basal area and
stemwood increment. Correlations with the latter two variables varied with time
and treatment.
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137. Turner, J. 1982. The mass
flow component of nutrient supply in three western Washington
forest types. Acta Oecologica Oecologia Plantarum 3(4): 323-329.
Keywords: fertilization
soil properties
growth
tree physiology
Abstract:
[See FA 37, 7318; 38, 5185; 39, 1857; 41, 3566; 44, 4913] The mass flow component of nutrient
uptake, defined as the product of bulk soil sol. concn. and water uptake was calculated for a series of
forest stands from previously published data. Stands were of Douglas fir of
varying ages and nutrient status (both undisturbed and fertilized), red alder
(Alnus rubra), Pacific silver fir (Abies amabilis) and beech (Fagus sylvatica).
Uptake of N, P, K, and Mg increased, and Ca uptake remained stable as stands
matured; the proportion of nutrient uptake fulfilled by mass flow tended to
increase with stand age. Fertilizer application gave various results related to
changes in soil sol. nutrient concn. and
tree growth. The stands of red alder and silver fir showed variable patterns
between nutrients and these are discussed in relation to soil nutrients,
productivity and previously unpublished data.
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138. Turner, J., D.W. Johnson and M.J. Lambert. 1980. Sulphur
cycling in a Douglas-fir forest and its modification by nitrogen application.
Acta Oecologica Oecologia Plantarum 1(1): 27-35.
Keywords: fertilization
soil properties
Abstract:
[See FA 39, 1857] In a study of a 42-yr-old nitrogen-deficient stand
in Washington State, subject to acid rain and elevated inputs of S, excess S
was found to be stored and cycled as SO4. A nitrogen (urea) fertilizer
experiment reported previously resulted in the incorporation of foliar SO4 into
organic S and a reduction in concn. of
litterfall SO4. Nitrogen stress induced in the same experiment by addition of
carbohydrate (sucrose and sawdust) to the forest floor resulted in greater
return of SO4 via litterfall.
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139. Turner, J., M.J. Lambert and S.P. Gessel. 1988. Nitrogen
requirements in young Douglas-fir of the Pacific
Northwest. Fertilizer-Research 15(2): 173-179.
Keywords: fertilization
growth
tree physiology
Abstract:
A series of fourteen Pacific
Northwest Douglas-fir installations, ranging in age
from 6 to 26 years were
analysed with respect to site factors, foliage nutrients, and growth response
to applied fertilizer. Unfertilized basal area increment ranged from 1.2 to 3.1
msuperscript 2 ha-1yr-1 with no apparent relationship with soil, stand age or
site index. Basal area increment was correlated with foliage N and a critical
level of N was calculated as 1.7%. Applications of 220 kg N ha-1 as urea
increased growth between 0 and 95% of the unfertilized basal area growth, with
an average of 24.9%. Response could be predicted from foliage N and
unfertilized basal area increment. When the same relationships were applied to
previously older stand data, results were more variable as elements such as B
and S showed evidence of being limiting.
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140. Velazquez-Martinez, A. and D.A. Perry. 1997. Factors influencing
the availability of nitrogen in thinned and unthinned Douglas-fir stands in the
central Oregon Cascades. Forest-Ecology-and-Management 93(3): 195-203.
Keywords: fertilization
thinning
soil properties
Abstract:
Soil N mineralized during 7-day anaerobic incubation at 40 degrees C (available
N) was compared at 2 soil depths and correlated with soil and site factors in
Douglas fir [Pseudotsuga menziesii] stands with different combinations of
thinning and multinutrient fertilizing. Available N expressed either on an area
basis (kg ha-1) or on a concentration basis (mg kg-1) at the 2 depths did not
vary significantly by stocking density, treatment, or density-treatment
interaction. There was a significant difference between the soil depths,
averaging 39 mg kg-1 at 0-20 cm depth, and 20 mg kg-1 at 20-40 cm depth.
Available N was positively correlated with total soil N, exchangeable Ca, and
adjusted aspect (the former 2 factors accounting for 46% of the total
variation), and negatively with rock content and slope steepness. Stand density
had no effect.
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141. Velazquez-Martinez, A., D.A. Perry and T.E. Bell. 1992. Response
of aboveground biomass increment, growth efficiency, and foliar nutrients to
thinning, fertilization, and pruning in young Douglas-fir plantations in the
central Oregon Cascades. Canadian-Journal-of-Forest-Research 22(9): 1278-1289.
Keywords: fertilization
thinning
pruning
growth
carbon allocation
tree physiology
tree morphology
Abstract:
The effect of thinning and silvicultural practices (multinutrient fertilization
and/or pruning) on total aboveground biomass increment and growth efficiency
was studied over three consecutive 2-year periods (1981-1987) in young Douglas
fir (Pseudotsuga menziesii) plantations in the central Oregon Cascades.
Plantations were 21-27 yr old in 1987. Plots were heavily thinned (leaving 300
trees/ha), moderately thinned (leaving 604 trees/ha) or left unthinned (leaving
3459 trees/ha) in 1981. Fertilizer (N, P, K, Ca, S and Fe) was applied with
slow-release tabs. Net above-ground biomass annual increment over the 6-year
period averaged 14.5, 7.8, and 5.5 t/ha for the high-, medium-, and low-density
plots, respectively. Growth efficiency, after dropping sharply between leaf
area indexes (LAI) of 1 and 6 msuperscript 2/msuperscript 2, remained
relatively constant up to the highest measured LAI of 17. Consequently,
above-ground biomass increment continued to increase at LAIs well above that at
which the Beer-Lambert law predicts maximum light should be absorbed. Foliage
analyses indicated that thinning improved N, K and Mg nutrition and increased
the translocation of K from 1-yr-old foliage to support new growth. However,
fertilizer application increased foliar N and P contents only when coupled with
pruning, suggesting that trees favour total leaf area over individual needle
nutrition. Indications of K and Mg limitations in this study are supported by
other recent studies of Douglas fir.
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142. Vogt, K.A., D.J. Vogt, E.E. Moore, W. Littke, C.C. Grier and L.
Leney. 1985. Estimating Douglas-fir fine root biomass and production from
living bark and starch. Canadian-Journal-of-Forest-Research 15(1): 177-179.
Keywords: fertilization
tree morphology
tree physiology
Abstract:
A potential indirect technique for determining fine root biomass and
production is reported. Data from 4 permanent Douglas fir plots in Washington State
given different fertilizer treatments showed a direct correlation between the
starch content of a 1-cm wide band of living bark at b.h. per hectare and fine
root biomass per hectare (rsuperscript 2 = 0.85). Starch content was determined
in bark samples from 5 trees in each plot and estimates of the volume of 1-cm
wide bands of bark at b.h. were made from measurements of d.b.h. and total bark
thickness of every tree in each plot. Fine root biomass was determined in soil
cores obtained with a post hole
digger (inner diam. 15.3 cm); traditional small core methods could not be used
because of the high gravel and rock content of the soil.
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143. Walker, R.B., S.P.
Gessel and R.E. Miller. 1994. Greenhouse and laboratory evaluation of two soils
derived from volcanic ash. Northwest-Science 68(4): 250-258.
Keywords: fertilization
growth
tree/stand health
carbon allocation
tree morphology
tree physiology
Abstract:
This study assessed the mineral nutrient status of two soils derived
from volcanic ash in SW Oregon.
The study was initiated because conifers in some of the field plots on such
soils had failed to give an expected yield response to the application of
nitrogen fertilizer. Soil pot tests were carried out using both Romaine lettuce
(Lactuca sativa) and Douglas fir (Pseudotsuga menziesii) seedlings, with a wide
range of fertilizer treatments. Heavy phosphorus fertilization was necessary
for satisfactory growth of lettuce, which also showed a 26% response to sulfur
addition. With Douglas fir, pot tests showed no response to nitrogen alone, but
gave a statistically significant response to phosphorus fertilization together
with nitrogen (seedlings were non-mycorrhizal), and some suppression of yield
with sulfur additions. There was a favourable effect of sulfur fertilization on
foliar colour, and a chlorosis in younger foliage probably attributable to iron
deficiency. Most of the tissue analyses showed low concentrations of magnesium
(<0.05%), and also of calcium (<less or =>0.08%), iron (<70 mg/kg),
boron (mostly 20 mg/kg) and copper (<less or =>2.6 mg/kg) in the younger
foliage. Thus there is an implication from the field trials, and evidence from
the greenhouse and laboratory study, that elements besides nitrogen need to be
added to provide proper nutrition on these volcanic ash soils. The information
can aid in guiding further fertilizer trials in forests on volcanic ash derived
soil in SW Oregon
and elsewhere.
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144. Weetman, G.F., C.E. Prescott, F.L. Kohlberger and R.M. Rournier.
1997. Ten-year growth
response of coastal Douglas-fir on Vancouver
Island to N and S fertilization in an optimum
nutrition trial. Canadian-Journal-of-Forest-Research 27(9): 1478-1482.
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.
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145. White, D.E. and M. Newton. 1990. Herbaceous weed control in young
conifer plantations with formulations of nitrogen and simazine.
Canadian-Journal-of-Forest-Research 20(11): 1685-1689.
Keywords: release
treatments
chemical release
fertilization
stand conditions
tree/stand health
growth
Abstract:
Weed control and second year survival and growth of newly planted 2+0 Douglas
fir (Pseudotsuga menziesii) and 2+0 noble fir (Abies procera) seedlings were
measured at 3 sites in Oregon after application of herbicide and fertilizer in
a replicated complete factorial experiment with 4 levels of simazine (0, 2.2,
4.4, 8.8 kg/ha), 3 levels of N (0, 110, 220 kg/ha), 2 types of N (urea prill;
urea + trimamino-s-triazine (TST) prill) and 2 kinds of formulations
(co-granular prill of simazine + nitrogen; nitrogen prill followed by liquid
simazine). For the first growing season, total weed and grass control increased
with increasing simazine rates. Total weed control was better when urea + TST,
rather than urea alone, was applied in conjunction with simazine. Formulation
and nitrogen rate were not significant. After plot treatment with 1.1 kg liquid
hexazinone/ha at the beginning of the second growing season, Douglas fir
survival decreased as the rate of urea alone increased; survival decreased with
little or no weed control and remained constant or increased with good weed
control as the rate of urea + TST increased. Noble fir height and diameter, and
Douglas fir diameter, decreased with poor weed control, but increased at least
to the levels of untreated seedlings with good weed control. Noble fir diameter
responded positively to added nitrogen. Although simazine may be toxic to first
year conifers, this study suggests that more complete weed control in
conjunction with fertilization may benefit young conifer plantations.
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146. White, D.E., L. Witherspoon-Joos and M. Newton. 1990. Herbaceous
weed control in conifer plantations with hexazinone and nitrogen formulations.
New-Forests 4(2): 97-105.
Keywords: release
treatments
chemical release
fertilization
stand conditions
growth
tree/stand health
Abstract:
In order to determine if herbicide efficacy is affected by nitrogen
fertilizer, and to examine the effects of treatments on growth and survival of
newly-planted 2-year-old Douglas fir (Pseudotsuga menziesii) and 3-year-old
noble fir (Abies procera), the influence of different nitrogen fertilizers
applied in different combinations with hexazinone formulations were evaluated
on three herbaceous weed communities in Oregon. Field studies comparing three
application methods in conifer plantations showed greatest reduction in total
weed cover with a co-granular formulation of hexazinone and the slow-release
nitrogen fertilizer triamino-s-triazine (TST). Slightly less control was
achieved with separate applications of liquid hexazinone and TST granules, and
poorest control with granular urea followed by liquid hexazinone. Weed control
increased with an increase in hexazinone rate. Statistical analysis of the
effect on conifers showed that the highest hexazinone rate significantly
increased survival of noble fir, stem diameter of both noble fir and Douglas
fir, and that the highest nitrogen rate significantly reduced survival of both
species but did not affect stem diameter. Survival of noble fir and diameter of
both noble fir and Douglas fir were significantly increased where a co-granular
formulation of hexazinone and TST granules was used.
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147. Wimberly, M.C. and B.B. Bare. 1996. Distance-dependent and
distance-independent models of Douglas-fir and western hemlock basal area
growth following silvicultural treatment. Forest-Ecology-and-Management
89(1/3): 1-11.
Keywords: fertilization
thinning
growth
Abstract:
Distance-independent and distance-dependent individual-tree basal area
growth equations for Douglas fir (Pseudotsuga menziesii) and western hemlock
(Tsuga heterophylla) growth following thinning and fertilizer treatments were
developed using regression analysis. Data came from an even-aged, naturally
regenerated, mixed species stand near Jordan
River, SW Vancouver Island, Canada.
Distance-independent models included only non-spatial competition and thinning
indices, while distance-dependent models included both spatial and non-spatial
indices. The distance-independent models with the highest adjusted multiple
coefficient of determination (adjusted Rsuperscript 2) for both species included
diameter at breast height, crown class, percent basal area removed in thinning,
plot basal area greater than the subject tree and stand age as independent
variables. The distance-dependent models with the highest adjusted Rsuperscript
2 included all of these variables in addition to a variant of the area
potentially available index, which is based on the spatial tessellation of the
point pattern of trees in the stand. Addition of this spatial index produced
only a small (<.01) increase in adjusted Rsuperscript 2 for models of both
species. The relatively small amount of increase was due to three factors:
thinning resulted in an even distribution of growing space among residual
trees; tree size explained much of the variation in local competitive stress;
and the competitive neighbourhood of individual trees was large relative to
sample plot size. The results suggest that the additional effort and expense
required to obtain spatially referenced stand data for developing empirical
forest growth models in similar stands is not justified.
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