1. 1994. Annual Report -
Keywords: genetic tree improvement
tree/stand protection
tree phenology
tree physiology
Abstract:
Highlights of research conducted during 1993-1994 are presented, including:
preliminary results of a 2-year (1992-94) field cold hardiness study of Douglas
fir [Pseudotsuga menziesii] in Oregon, USA involving open pollinated progeny of
40 parents at a high and a low elevation; results of a progeny test on the
frequency of second flushing of Douglas fir near Orleans, France; and variation
in stable carbon isotope ratios (a measure of water use efficiency) among
varieties and populations (coastal and Rocky Mountain) of Douglas fir.
2. 1997. PNWTIRC Annual Report
1996-97,
Keywords: genetic tree improvement
tree/stand protection
tree phenology
growth
wood quality
tree physiology
Abstract: The
report describes highlights for 1996-97, current research (3 projects), student
project updates (3 projects), planned Douglas fir [Pseudotsuga menziesii] seed
orchards for the new millennium and other planned activities of the PNWTIRC, a
research cooperative operating in the Pacific Northwest area of North America
(USA and Canada). Details are included of publications and finances. Details of
the 3 current research projects and the 3 student projects, which all concern
Douglas fir, are presented as short papers including brief results: (1)
Influence of second flushing on cold hardiness; (2) Seedling drought physiology
study; and (3) Quantitative trait loci influencing cold hardiness; (4) Seedling
cold hardiness; (5) Growth response of saplings to drought; and (6) Measurement
study follow-up: age-age correlations in forking defects.
3. 2000. Annual
Report 1999/2000 -
Keywords: genetic tree improvement
tree/stand protection
tree physiology
reproduction
Abstract:
Includes highlights of 1998-1999; a note to the cooperative members from Tom
Adams; Introduction; Current research on seedling drought physiology of Douglas
fir [Pseudotsuga menziesii], field drought study - genetics of drought sensitivity
in older trees, early testing revisited, miniaturized orchard study, pollen
contamination study; activities planned for 2000-2001; list of staff
publications and abstracts; and a summary of financial support for the fiscal
year 1999-2000.
4.
Keywords: genetic tree improvement
tree/stand protection
tree/stand health
growth
tree physiology
Abstract: Summaries
are given of research projects on improvement of Douglas fir [Pseudotsuga
menziesii] in the Pacific Northwest: seedling drought physiology; genetics of
dark respiration and its relationship with drought hardiness; response of
saplings to drought, as measured by growth ring variables; use of
microsatellite marker loci to identify pollen contamination in seed orchards;
and evaluation of miniaturized seed orchard designs.
OSU
Link
Non-OSU
Link
5. Aitken, S.N. and W.T. Adams. 1996.
Genetics of fall and winter cold hardiness of coastal Douglas-fir in
Keywords: genetic tree improvement
tree/stand protection
tree/stand health
tree physiology
genetic relationships
Abstract: Genetic
variation in autumn cold hardiness was studied in two western
OSU
Link
Non-OSU
Link
6. Aitken, S.N. and W.T. Adams. 1997.
Spring cold hardiness under strong genetic control in
Keywords: genetic tree improvement
tree/stand protection
tree/stand health
tree phenology
tree physiology
genetic relationships
Abstract: Genetic
variation in spring cold hardiness of shoots prior to bud break was studied in
two
7. Aitken, S.N., W.T. Adams, N.
Schermann and L.H. Fuchigami. 1996. Family variation for fall cold hardiness in
two
Keywords: genetic tree improvement
tree/stand protection
tree/stand health
tree physiology
tree phenology
genetic relationships
Abstract: In
order to assess the genetics of autumn (fall) cold hardiness in coastal Douglas
fir (Pseudotsuga menziesii var. menziesii), shoot cuttings were collected in October
from saplings (9-year-old trees) of open-pollinated families in two progeny
tests in each of two breeding zones in Washington, one in the Coast range (80
families) and one on the west slope of the Cascade Mountains (89 families).
Samples from over 5500 trees were subjected to artificial freezing and visually
evaluated for needle, stem and bud tissue injury. The extent to which cold
injury is genetically related to tree height and shoot phenology (timing of bud
burst and bud set) was also evaluated. Significant family variation was found
for all cold hardiness traits; however, individual heritability estimates were
relatively low (ranging from 0.09 to 0.22). Significant family-by-test site
interaction was detected for needle injury in the Cascade breeding zone, but
not in the coastal zone. Genetic correlations (rA) among needle, stem and bud
tissues for cold damage were weak (0.16<less or =>rA<less or
=>0.58) indicating that genes controlling autumn cold hardening are somewhat
different for different tissues. Timing of bud burst and bud set were only
weakly correlated with cold injury (rA<less or =>0.49). Thus, bud
phenology is a poor predictor of autumn cold hardiness in this species. There
was no consistent relationship between tree height and cold injury in the
coastal zone. In the Cascade zone, taller trees appeared to be more susceptible
to cold injury, but the association was weak (mean rA=0.38, range 0.20-0.72).
OSU
Link
Non-OSU
Link
8. Anekonda, T.S., M.C. Lomas, W.T.
Adams, K.L. Kavanagh and S.N. Aitken. 2002. Genetic variation in drought hardiness
of coastal Douglas-fir seedlings from
Keywords: genetic tree improvement
tree/stand protection
growth
tree/stand health
genetic relationships
tree physiology
Abstract: Genetic
variation in drought hardiness traits and their genetic correlations with
growth potential and recovery traits were investigated in 39 full-sib families
of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) from southwestern
OSU
Link
Non-OSU
Link
9. 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.,
10. 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.
11. 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.
12. Birchler, T.M., R. Rose and D.L. Haase.
2001. Fall fertilization with N and K: effects on Douglas-fir seedling quality
and performance. Western-Journal-of-Applied-Forestry 16(2): 71-79.
Keywords: nursery operations
nursery fertilization
growth
tree physiology
tree morphology
tree/stand health
Abstract: Coastal
Douglas fir (Pseudotsuga menziesii) 1+1 seedlings from coastal
13. Black, C.H. 1988. Interaction of phosphorus fertilizer form and soil medium on
Douglas-fir seedling phosphorus content, growth and photosynthesis.
Plant-and-Soil 106(2): 191-199.
Keywords: nursery operations
nursery fertilization
growth
tree physiology
photosynthesis
Abstract:
Douglas-fir seedlings were grown in containers in peat-vermiculite or mineral
soil each amended with different levels of concentrated superphosphate (CSP) or
a granulated
14. 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.
15. Bledsoe, C.S. and R.J. Zasoski.
1983. Effects of ammonium and nitrate on growth and nitrogen uptake by mycorrhizal
Douglas-fir seedlings. In Tree root systems and their mycorrhizas. Ed.
D. Atkinson. pp. 445-454.
Keywords: nursery operations
nursery fertilization
growth
tree physiology
tree morphology
tree/stand health
Abstract: In a
greenhouse pot study, 1-yr-old mycorrhizal (inoculated with Hebeloma
crustuliniforme) and non-mycorrhizal Douglas fir seedlings were grown in sandy
forest soil amended with 10% of clay minerals (bentonite and/or kaolinite) and
ammonium or nitrate fertilizer. Ht. growth, root and shoot DM and accumulation
of nitrogen and P were greater in mycorrhizal than non-mycorrhizal seedlings,
especially in the nitrate treatment. Ammonium interacted with kaolinite to
reduce survival which again was poorer in the absence of mycorrhiza.
16. Brand, D.G. 1986b.
Competition-induced changes in developmental features of planted Douglas-fir in
southwestern
Keywords: planting operations
tree morphology
tree physiology
growth
Abstract: From
measurements in 1- to 5-yr-old plantations, developmental characteristics of
Douglas fir were tested against a competition index based on measures of the
brush canopy surrounding individual trees. The most promising characteristics
for assessing competition were specific leaf area, the allometric relationship
of ht. to b.a. and bud production on nodal shoots.
Measures of foliar N and leaf internode length were less well correlated with
the competition index. Comparing these results with those of laboratory studies
indicated that, on the study sites, brush competition effects on planted trees
are expressed through adaptation to reduced light intensity. Developmental
variables relating to moisture and nutritional status were not as strongly
related to the competition index. This may reflect reduced tree demand or
secondary brush canopy effects.
17. Brix, H. 1993. Fertilization and
thinning effect on a Douglas-fir ecosystem at
Keywords: fertilization
thinning
growth
tree morphology
tree/stand health
carbon allocation
wood quality
tree physiology
photosynthesis
economics
Abstract:
Treatments were initiated in 1970-71 in a 24-year-old Douglas fir (Pseudotsuga
menziesii) near Shawnigan Lake, Vancouver Island, British Columbia, to
determine the effects of 3 intensities of thinning (removing none, one-third
and two-thirds of basal area) and 3 levels of urea fertilizer (0, 224 and 448
kg N/ha) on the growth and biology of the trees. Subsidiary experiments were
established during 1972-87 to examine the effects of high doses of urea
(672-1344 kg N/ha), ammonium nitrate as an N source instead of urea,
understorey response to thinning and fertilizer, and responses to P and S
fertilizer.
18. 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
19. 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.
20. 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 (
21. 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
22. Chastagner, G.A., R.S. Byther,
J.D. MacDonald and E. Michaels. 1984. Impact of Swiss needle cast on
postharvest hydration and needle retention of Douglas-fir Christmas trees.
Plant-Disease 68(3): 192-195.
Keywords: tree/stand protection
tree/stand health
tree physiology
Abstract: Healthy
Douglas-fir (Pseudotsuga menziesii) Christmas trees were compared with those
infected by Phaeocryptopus gaeumannii for needle loss and dehydration after
cutting. The presence of infected needles increased the rate of dehydration (as
measured by changes in xylem water potential) of cut trees placed in water or
left dry. Fungicide applications 1 yr before harvest significantly improved
retention of 1-yr-old needles on trees displayed either wet or dry, whereas
applications during the year of harvest made no difference in retention of
either current-season or 1-yr-old needles.
23. Childs, S.W. and L.E. Flint.
1987. Effect of shadecards, shelterwoods, and clearcuts on temperature and
moisture environments. Forest-Ecology-and-Management 18(3): 205-217.
Keywords: planting operations
tree/stand health
soil properties
tree physiology
tree phenology
Abstract: A
comparison was made of two common techniques used to improve seedling survival on
hot, dry reforestation sites. Adjacent shelterwood and clearcut sites in
24. Cochran, P.H., W. Lopushinsky and
P.D. McColley. 1986. Effect of operational fertilization on foliar nutrient
content and growth of young Douglas-fir and Pacific silver fir. Pacific-Northwest-Research-Station,-USDA-
Keywords: fertilization
tree physiology
growth
Abstract: During
1979-80, sulfated urea (pelletted) was applied to conifer stands in the
25. Coleman, M., J. Dunlap, D. Dutton
and C. Bledsoe. 1987. Nursery and field evaluation of compost-grown conifer
seedlings. Tree-Planters' Notes 38(2): 22-27.
Keywords: nursery operations
nursery
fertilization
growth
tree
physiology
tree/stand health
Abstract:
Seedlings of Douglas fir (Pseudotsuga menziesii), noble fir (Abies procera) and
ponderosa pine (Pinus ponderosa) were raised in beds that had been treated with
0, 2, 4 or 6 inches of compost (fir/hemlock sawdust and municipal sewage
sludge, 3:1) at a nursery in Carson, Washington. In autumn 1983, the 2+0 stock
was lifted, stored until spring 1984 and then planted out on
26. Coleman, M.D., C.S. Bledsoe and
B.A. Smit. 1990. Root hydraulic conductivity and xylem sap levels of zeatin
riboside and abscisic acid in ectomycorrhizal Douglas fir seedlings.
New-Phytologist 115(2): 275-284.
Keywords: nursery operations
nursery fertilization
tree
morphology
tree physiology
mycorrhizal response
Abstract: The hypothesis that root hydraulic conductivity (LP) of ectomycorrhizal root
systems is greater than that of non-mycorrhizal systems, and different to that
of vesicular-arbuscular (VA) mycorrhizas was tested in a greenhouse experiment,
by measuring hydraulic qualities of roots while accounting for seedling size and
P content. Plant growth substances (abscisic acid and zeatin riboside)
expressed from roots during the experiments were also
measured. Douglas fir (Pseudotsuga menziesii) seedlings inoculated with the
ectomycorrhizal fungi Laccaria bicolor and Hebeloma crustuliniforme, and
non-inoculated seedlings infected naturally with Thelephora were grown under 3
rates of P fertilization (1, 10 and 100 micro M P). After 9 months, seedling
morphology, tissue P concn., LP and plant growth
substance concn. in xylem sap were measured. Increased
tissue P and decreased root/shoot ratio correlated with increased LP in each
mycorrhizal treatment; when adjusted for the effect of these 2 factors, LP of
Laccaria and Hebeloma seedlings was still lower than that of Thelephora seedlings.
In a subsequent experiment, LP of seedlings with Hebeloma and Rhizopogon
vinicolor mycorrhizas was compared with that of non-mycorrhizal seedlings
(grown at 100 mM P) and no differences were found among treatments. The lack of
an ectomycorrhizal effect on LP is quite different from the enhancement of host
LP by VA mycorrhizas. Zeatin riboside concentrations of Thelephora- and
Hebeloma-infected seedlings were similar, yet higher than with Laccaria. There
was no relationship between plant growth substances and LP in ectomycorrhizal
Douglas fir, despite lower zeatin riboside concentrations for
Laccaria-inoculated plants.
27. Copes, D.L. 1989. Bark scoring
problem grafts in five Douglas-fir seed orchards: a case history. Pacific-Northwest-Research-Station,-USDA-
Keywords: genetic tree improvement
tree grafting
tree/stand health
tree physiology
Abstract: Grafted
seed orchards of Douglas fir (Pseudotsuga menziesii) often suffer tree losses caused
by delayed graft incompatibility. Bark scoring (to improve translocation across
the graft union) was performed in April, June and August 1983 and 1985 on 379
trees, 5-16 yr old, in 5 seed orchards in western Oregon. Cuts were made with a
small chainsaw every 3.1 to 4.3 cm across the defective union. Effects of
scoring were assessed in 1984 and 1986. Many trees showed improved vigour after
treatment and annual mortality was only 1.6% when all defective grafts were
treated. The greatest improvement in average compatibility occurred in trees
treated in April, when the youngest grafts responded most favourably. Inherent
and induced incompatibility was found, with brownline round the entire or part
of the circumference of the union, respectively. Wound tissue in induced
incompatible grafts was usually free of brownline, but brownline appeared in
all wound tissue of inherently incompatible grafts. These latter grafts will
require bark scoring every 2-3 yr to maintain a live cambium at the union.
28. Crouch, G.L. and M.A. Radwan.
1981. Effects of nitrogen and phosphorus fertilizers on deer browsing and
growth of young Douglas-fir. Pacific-Northwest-Forest-and-Range-Experiment-Station,-USDA-
Keywords: fertilization
tree/stand health
growth
tree physiology
Abstract: N and P
fertilizers were applied in March 1968 singly or in combination at a rate
equivalent to 200 lb/acre of N or P to young trees (2-5 ft tall) in
29. Dangerfield, J. and H. Brix.
1981. Comparative effects of ammonium nitrate and urea fertilizers on tree
growth and soil processes. In Proceedings:
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.
30. 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
31. 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.
32. Driessche, R.v.-d. 1983. Growth,
survival, and physiology of Douglas-fir seedlings following root wrenching and
fertilization. Canadian-Journal-of-Forest-Research 13(2): 270-278.
Keywords: nursery operations
nursery fertilization
tree/stand health
tree morphology
tree physiology
growth
Abstract:
Seedlings at different nurseries on
33. Driessche, R.v.-d. 1984a. Response of Douglas fir seedlings to phosphorus
fertilization and influence of temperature on this response.
Plant-and-Soil 80(2): 155-169.
Keywords: nursery operations
nursery fertilization
growth
tree physiology
carbon allocation
tree morphology
Abstract: In pot
experiments levels of P fertilizers equivalent to 300 kg/ha were adequate for
maximum growth of Douglas fir (Pseudotsuga menziesii var. menziesii) seedlings
over 14-18 weeks, and resulted in available soil P levels of 80 ppm after 15
weeks' growth. Maximum growth in pots was obtained with shoot P concentrations
of 0.18%-0.20%, with higher values at lower temperatures, but the optimum
concentration for one-year-old (1-0) nursery seedlings was 0.16% P. Growth of
seedlings was greatly restricted at a soil temperature of 5 degrees C and an
air temperature of 12 degrees C. At a soil temperature of 10 degrees C and an air
temperature of 14 degrees C seedling P requirement was greater than at soil and
air temperatures of 20 degrees C. Monoammonium phosphate was more effective
than calcium superphosphate in stimulating growth in pots and nursery beds.
Triple superphosphate was also effective in the nursery. Diammonium phosphate,
potassium dihydrogen phosphate and phosphoric acid had no advantages as P
sources in the nursery. Available P levels of 100-130 ppm, in the loamy sand
and sandy loam nurseries studied, and needle P concentrations of 0.18%, when
sampled in October, were associated with maximum growth of two-year-old (2-0)
seedlings. P fertilization decreased the root/shoot ratio, but did not alter
the allometric relationship of shoot to root. Improving the P status from a low
level increased the root growth capacity in 2-0 seedlings and P fertilization
of potted seedlings increased the dry weight/height ratio. Uptakes per seed bed
ha of 236 kg N, 31 kg P, 81 kg K and 73 kg Ca by 2-0 seedlings were comparable
with, or greater than, uptake rates of agricultural crops. Recoveries of 6-11%
of P from fertilizer were recorded in the nursery.
34. Driessche, R.v.-d. 1984b. Seedling spacing in the nursery in relation to growth,
yield, and performance of stock. Forestry-Chronicle 60(6): 345-355.
Keywords: nursery operations
growth
tree morphology
carbon allocation
tree physiology
tree/stand health
Abstract: In 3
experiments at nurseries in coastal British Columbia Picea sitchensis, P.
glauca, Pinus contorta var. latifolia, Thuja plicata and coastal and interior
varieties of Pseudotsuga menziesii were sown in May 1979, 1980 or 1982 and
grown at spacings ranging from 0.5 to 12 cm. A 1-cm increase in spacing
increased seedling dry wt. by 0.5-1.5 g and root collar diam. by 0.2-0.25 mm up
to a spacing of about 8-10 cm. Above this, response was less. Ht. of 2-yr-old seedlings
was increased slightly or even decreased by wider spacing. Height
: diameter ratios decreased sharply and shoot : root dry wt. decreased
or remained unchanged with wider spacing. The number of needle primordia in 2-0
P. menziesii buds increased up to a spacing of 2 cm, and the number of 1st and
2nd order branches were also increased by wider spacing. Increases in root
growth capacity were associated with wider spacing in T. plicata and Picea
sitchensis. In a test of 3 types of precision seeders, none produced anything
like accurate seed placement. Irregularity was increased by 10-20% non-viable
seed and winter mortality. Increased spacing of 2-5 cm between seedlings was
justified by the yield of acceptable seedlings only when the culling standard
was increased to a root collar diam. of about 6 mm. Three yr after planting out
the survival of P. glauca was increased 11% by wider spacing. After 2 yr P.
sitchensis survival was increased 13% by wider spacing. Both species grown at
wider spacing maintained a ht. and diam. advantage over those from close
spacing.
35. Driessche, R.v.-d. 1987.
Importance of current photosynthate to new root growth in planted conifer
seedlings. Canadian-Journal-of-Forest-Research 17(8): 776-782.
Keywords: nursery operations
tree physiology
photosynthesis
tree morphology
Abstract: Reports
are given of 6 experiments. Two-yr-old seedlings of Douglas fir and