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. 2001. Common insects and diseases of interior Douglas-fir. British Columbia Ministry of Forests SIL471. 8 p.
Keywords: tree/stand protection
tree/stand health
Abstract: This
field guide provides information on the different pests and diseases of the
interior Douglas fir (Pseudotsuga menziesii) in British Columbia which include:
defoliating insects (Douglas fir tussock moth, spruce budworm and rusty tussock
moth); dwarf mistletoe; foliar diseases (e.g., caused by the Cooley spruce
adelgid); bark beetles; root diseases (Armillaria root disease, blackstain root
disease, laminated root rot and blackstain root disease); wood decay (caused by
bracket or conk fungi); and various abiotic problems (sunscald, drought or
frost). A guideline to control infestations of these given pests is also
included.
5.
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
6. 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
7. 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
8. 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
9. 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
10. Antonelli, A.L. and R.L.
Campbell. 1991. Cooley spruce gall aphid. College of
Agriculture and Home Economics,
Keywords: tree/stand protection
tree/stand health
Abstract: Notes
are provided on the biology, injuriousness and chemical control (carbaryl and
endosulfan are suggested) of Adelges cooleyi [Gilletteella cooleyi] on certain
coniferous trees [including Picea sitchensis, P. engelmannii, P. pungens and
Pseudotsuga menziesii] in
11. Axelrood, P.E., W.K. Chapman,
K.A. Seifert, D.B. Trotter and G. Shrimpton. 1998. Cylindrocarpon and Fusarium
root colonization of Douglas-fir seedlings from
Keywords: planting operations
tree/stand protection
tree/stand health
Abstract: Poor
performance of Douglas fir (Pseudotsuga menziesii) plantations established in
1987 has occurred in southwestern
12. Axelrood, P.E., M. Neumann, D.
Trotter, R. Radley, G. Shrimpton and J. Dennis. 1995. Seedborne Fusarium on
Douglas-fir: pathogenicity and seed stratification method to decrease Fusarium
contamination. New-Forests 9(1): 35-51.
Keywords: nursery operations
tree/stand protection
tree/stand health
growth
Abstract: Twelve
Douglas-fir (Pseudotsuga menziesii) seedlots from coastal
13. Axelrood, P.E. and R. Radley.
1991. Biological control of Fusarium on Douglas-fir seedlings. Bulletin-SROP
14(8): 85-87.
Keywords: nursery operations
tree/stand protection
tree/stand health
Abstract: A
bacterial culture collection was established from the rhizosphere and
rhizoplane of Douglas fir (Pseudotsuga menziesii) seedlings collected from
nursery and forest locations in
14. Bloomberg, W.J. 1988. Modeling
control strategies for laminated root rot in managed Douglas-fir stands: model
development. Phytopathology 78(4): 403-409.
Keywords: planting operations
site preparation
mechanical preparation
tree/stand protection
tree/stand health
Abstract: A model
of laminated root rot caused by Phellinus [Inonotus] weirii was developed to
assess potential control strategies in managed Pseudotsuga menziesii stands.
The model mimicked key processes in disease initiation and development
quantified as functions of time and space. These processes were horizontal and
vertical tree root distribution, root contact with inoculum and among root
systems, spread of mycelium through root systems, root decay, reduction of
diam. growth in infected trees, tree mortality and persistence of inoculum in
roots of stumps and killed trees. The processes were expressed as mathematical
functions which were integrated in a computer program to calculate spread of
the disease and stand-growth loss and mortality. Data for quantification of
functions were obtained by experiments and from the literature. Simulated
control practices included infected stump removal, sanitation fellings and
mixed planting of Douglas fir and resistant species. Accuracy of the model was
tested by comparing calculated disease spread and mortality with the following
data: (1) spread and damage in two 60-yr-old, 1-ha stands in Oregon, (2)
results from a statistically based model for spread and damage that had
performed satisfactorily, and (3) observed spread and damage behaviour in
stands of different ages and growth rates. Results from the model compared
favourably with all of the above situations.
15. Bloomberg, W.J. and G. Reynolds.
1988. Equipment trials for uprooting root-rot-infected stumps.
Western-Journal-of-Applied-Forestry 3(3): 80-82.
Keywords: site preparation
mechanical preparation
tree/stand protection
tree/stand health
Abstract:
Residual roots from Douglas fir (Pseudotsuga menziesii) and western hemlock
(Tsuga heterophylla) were measured following stump-root extraction one yr after
harvesting a 55-yr-old, 314 stems/ha, 47% Douglas fir, 17% maple (Acer
macrophyllum), 16% red cedar (Thuja plicata), 6% western hemlock stand with 20%
infection by Phellinus weirii in the Cowichan valley, Vancouver Island, Canada.
Extraction was by a Caterpillar D8H with brush-clearing blade, a 180-hp backhoe
or a 115-hp backhoe. All 3 machines recovered more than 90% of root vol. The
small backhoe left significantly greater numbers and lengths of root residues
per msuperscript 3 soil, though the vol. of residues was greatest for the
Caterpillar. An earlier study suggested that a root density of
32 roots/msuperscript 3 was needed to produce one root contact; as the
least efficient treatment by the Caterpillar left 23.2 roots/msuperscript 3 in
the ground, it is suggested that this would provide insufficient contacts with
a new tree crop to transmit infection.
16. Brandeis, T.J., M. Newton and
E.C. Cole. 2002. Biotic injuries on conifer seedlings planted in forest
understory environments. New Forests 24:1-14.
Keywords: planting operations
site preparation
chemical preparation
release treatments
chemical release
thinning
tree/stand protection
growth
tree/stand health
Abstract: The
effects of partial overstorey retention, understorey vegetation management, and
protective Vexar(R) tubing on the frequency and severity of biotic injuries in
a two-storied stand underplanted with western redcedar (Thuja plicata),
Douglas-fir (Pseudotsuga menziesii), grand fir (Abies grandis), and western
hemlock (Tsuga heterophylla) were investigated. The most prevalent source of
damage was browsing by black-tailed deer (Odocoileus hemionis columbiana); deer
browsed over 74% of Douglas-fir and over 36% of western redcedar seedlings one
or more times over the four years of this study. Neither the spatial pattern of
thinning (even or uneven) nor the density of residual overstorey affected
browsing frequency. Spraying subplots may have slightly increased browsing frequency,
but the resulting reduction of the adjacent understorey vegetation increased
the volume of all seedlings by 13%, whether or not they were browsed. Vexar(R)
tubing did not substantially affect seedling survival, browsing damage
frequency, or fourth-year volume. Greater levels of overstorey retention
reduced frequency of second flushing. Chafing by deer and girdling by rodents
and other small mammals began once seedlings surpassed 1 m in height.
Essentially all grand fir seedlings exhibited a foliar fungus infection.
17.
Keywords: tree/stand protection
tree/stand health
Abstract: Investigations
by the
18. Campbell, S.J. and P.B. Hamm.
1989. Susceptibility of
Keywords: nursery operations
tree/stand protection
tree/stand health
Abstract: One-yr-old
bare-rooted seedlings of 11 conifer species were inoculated with (a)
Phytophthora cactorum, (b) P. cryptogea, (c) P. drechsleri, (d) P. megasperma
or (e) P. pseudotsugae. Development of above-ground symptoms and root disease
was followed for 10 wk. Isolates of (a), (b) and (e) caused the most overall
mortality and isolates of (d) the least. Pinus contorta, P. ponderosa, P.
monticola, Larix occidentalis, Libocedrus decurrens, Picea sitchensis and P.
engelmannii showed tolerance to the root disease, Abies grandis and Pseudotsuga
menziesii showed intermediate susceptibility and A. magnifica and Tsuga
mertensiana were quite susceptible. Results are discussed in relation to
management of conifer nurseries in the
19. Carroll, G.C. 1988. Facultative fungal egg-parasites as agents of gypsy moth mortality.
Northwest-Environmental-Journal 4(2): 345-346.
Keywords: tree/stand protection
tree/stand health
Abstract: Research
on entomogenous fungi attacking the forest pest Lymantria dispar in
20. Chanway, C.P. 1997. Inoculation
of tree roots with plant growth promoting soil bacteria: an emerging technology
for reforestation. Forest-Science 43(1): 99-112.
Keywords: nursery
operations
tree/stand protection
growth
tree/stand health
mycorrhizal response
Abstract: Results
from studies performed with beneficial asymbiotic tree root associated bacteria
are reviewed in this article in relation to the possible uses of such
microorganisms for artificial forest regeneration. The review includes sections
on plant growth promoting bacteria for pine (Pinus spp.), spruce (Picea spp.),
Douglas fir (Pseudotsuga menziesii) and hemlock (Tsuga heterophylla). Seedling
root systems are colonized heavily by asymbiotic soil bacteria, many of which
have the potential to influence plant growth significantly. A heterogeneous
group of these microorganisms is well known for their ability to colonize roots
and stimulate growth of agricultural plant species, sometimes doubling seedling
biomass accumulation only a few weeks after inoculation, but more usually
resulting in less spectacular biomass gains (e.g., 15%-30% greater than
uninoculated controls within a growing season). Plant growth promoting soil
bacteria may exert such effects through a variety of mechanisms, and include
microorganisms that stimulate seedling emergence or infection by symbiotic
fungi and bacteria. Other plant beneficial soil bacteria possess biological
control activity or are capable of transforming plants genetically. Inoculation
of tree seedlings with such bacterial before outplanting would be an
inexpensive, environmentally benign, and easily applied nursery treatment, but
comparatively little work has been performed with these microorganisms in
forestry. Recent results with various tree species, however, indicate that
seedling performance can be significantly enhanced through bacterial
inoculation of root systems: pine and spruce biomass increased 32%-49% 1 yr
after inoculation and outplanting at a reforestation site. In addition,
infection by desired species of ectomycorrhizal fungi can also be enhanced by
inoculation with certain strains of root colonizing bacteria.
21. 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.
22. Colangeli, A.M., L. McAuley and
J.N. Owens. 1990. Seasonal occurrence of potential ice-nucleating bacteria on
Douglas fir foliage and seed cones. New-Forests 4(1): 55-61.
Keywords: seed orchard management
tree/stand protection
tree/stand health
reproduction
Abstract: Plant
frost damage can involve interactions between certain surface bacteria and low
temperatures. The bacteria contain glycoproteins, which can nucleate ice above
-5 degrees C, thus making the plants on which they live more susceptible to
freezing. Preliminary studies to determine if bacteria were present on Douglas
fir (Pseudotsuga menziesii), and whether they exhibited ice-nucleating
properties, are reported. Total bacteria and fluorescent Pseudomonas
populations were monitored on buds, conelets and foliage of five trees in a
Douglas fir seed orchard on
23. Colangeli, A.M., J.N. Owens and
S.J. Morris. 1989. Factors affecting cone and seed production in Douglas fir. BC Ministry of Forests FRDA-Report 057. 19
p.
Keywords: seed orchard management
tree/stand protection
reproduction
Abstract: Reduced
seed yield in 1986 on 4 Pseudotsuga menziesii trees in a
24. Copes, D.L. 1999. Breeding graft-compatible Douglas-fir rootstocks (Pseudotsuga
menziesii (MIRB.) FRANCO). Silvae-Genetica 48(3/4): 188-193.
Keywords: genetic tree improvement
tree grafting
tree/stand protection
growth
tree phenology
tree/stand health
genetic relationships
Abstract: A study
encompassing 24 years was conducted to determine if a breeding programme could
produce highly graft-compatible rootstocks for P. menziesii. A total of 27
trees of apparent high graft compatibility were selected and crossed to produce
226 control-pollinated families. Seedlings were grown, field planted and
grafted with test scions. Graft unions from field tests were evaluated
anatomically for internal symptoms of incompatibility. Average compatibility of
progeny from the 226 crosses was 90.6%, compared with 65% in native
populations. Breeding values were calculated for each parent by the best linear
prediction (BLP) procedure. Average compatibility resulting from crossing among
the top 10 parents was estimated by breeding values as 95.4%. Field-test
results of progeny from 34 crosses among the 10 most compatible parents showed
96% compatibility. In addition to field-tests for graft compatibility, nursery
tests of seedlings from 124 crosses were evaluated for second-year vegetative
bud flush and seedling height. It was possible, while maintaining adequately
high levels of graft compatibility, to breed both for resistance to spring
frost damage and for increased seedling height.
25. DeYoe, D.R., H.R. Holbo and K.
Waddell. 1986. Seedling protection from heat stress between lifting and
planting. Western-Journal-of-Applied-Forestry 1(4): 124-126.
Keywords: nursery operations
planting operations
tree/stand protection
tree/stand health
Abstract: Seven
protective treatments were evaluated for preventing overheating of 2+0 Douglas
fir seedlings in Kraft paper bags. Trials were conducted in May 1982 at
26. Donald, D.G.M. and D.G. Simpson.
1985. Shallow conditioning and late fertilizer application effects on the
quality of conifer nursery stock in
Keywords: nursery operations
nursery fertilization
tree/stand protection
tree morphology
tree/stand health
growth
Abstract: Eight
trials on 2+0 stock of Picea engelmannii, P. glauca, P. sitchensis, Pinus
contorta and Pseudotsuga menziesii (var. glauca and var. menziesii) in 4
nurseries were conducted to compare the effects of shallow conditioning (undercutting
and wrenching at 10 cm deep) with those of the standard conditioning regime
(undercutting and wrenching at 20 cm) on nursery performance, storage and field
performance. The application of a complete NPK fertilizer 50 days before
lifting was also evaluated. Shallow conditioning and late fertilizer
application improved the root growth capacity at lifting, but could not replace
cold exposure for hardening Pseudotsuga menziesii. Shallow conditioning had
little effect on survival after planting and reduced initial ht. increment of
all species. Application of fertilizer just before lifting improved the early
growth of the trees without adversely affecting survival. Planting
seedlings some 5 cm deeper than they stood in the nursery improved
establishment.
27. 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.
28. Drew, A.P. 1983. Optimizing growth and development of 2-0 Douglas-fir seedlings by
altering light intensity. Canadian-Journal-of-Forest-Research 13(3):
425-428.
Keywords: nursery operations
tree/stand protection
growth
tree morphology
carbon allocation
Abstract:
Seedlings were grown outdoors in
29. Driessche, R.v.-d. 1991a.
Influence of container nursery regimes on drought resistance of seedlings
following planting. I. Survival and growth. Canadian-Journal-of-Forest-Research
21(5): 555-565.
Keywords: nursery operations
tree/stand protection
growth
tree morphology
carbon allocation
tree/stand health
Abstract: In a 2
year study, Douglas fir (Pseudotsuga menziesii), lodgepole pine (Pinus contorta)
and white spruce (Picea glauca) seedlings, grown in Styroblock containers in a
container nursery from February to July 1988, were exposed to three
temperatures and three levels of drought stress applied factorially during 18
July to 29 September 1988. Mean temperatures of 13, 16 and 20 degrees C were
imposed in growth chambers, in a cooled plastic house, and in an ambient
plastic house, respectively. Control, medium and severe levels of drought
stress were imposed in a series of eight cycles, resulting in mean xylem
pressure potentials of -0.32, -0.50 and -0.99 MPa, respectively. Seedlings were
kept in the ambient plastic house until January 1989, when they were lifted and
cold-stored until transplanting to covered 0.5-m deep sand beds, which provided
hygric, mesic, and xeric conditions for testing all species and treatments. At
the end of nursery growth, an increase in nursery temperature increased height
and height : diameter ratio in all species and
shoot:root dry weight ratio in Douglas fir and lodgepole pine. Increase in
temperature also increased the number of seedlings with large well-formed buds
in white spruce, but reduced the number in Douglas fir. Drought stress reduced
height and dry weight in all species and bud length in lodgepole pine. After 9
weeks in sand beds, low nursery temperature increased survival (19% for
lodgepole pine and white spruce grown in the xeric bed), except for Douglas fir
grown in the xeric bed. Nursery drought stress also increased survival (16% for
Douglas fir and lodgepole pine in the xeric bed), but had little effect on
white spruce. Low temperature and drought stress treatments that increased
survival also reduced height and dry weight of lodgepole pine and white spruce
after one growing season in sand beds. Survival showed significant negative
correlations with height, dry weight and height:diameter
and shoot : root weight ratios. Low nursery temperature continued to affect
growth 16 weeks after planting, increasing relative growth rate and allometric
ratio (K) of Douglas fir and reducing K of white spruce.
30. Driessche, R.v.-d. 1991b.
Influence of container nursery regimes on drought resistance of seedlings
following planting. II. Stomatal conductance, specific leaf area, and root
growth capacity. Canadian-Journal-of-Forest-Research 21(5): 566-572.
Keywords: nursery operations
tree/stand protection
tree physiology
tree/stand health
Abstract: Seedlings
of Douglas fir (Pseudotsuga menziesii), lodgepole pine (Pinus contorta) and
white spruce (Picea glauca) were grown in a container nursery from February to
July 1988 and then exposed to three temperatures and three levels of drought
stress applied factorially during mid-July to October 1988. Seedlings were
retained in a shelter house until January 1989, when they were cold-stored
until early May. Measurements of stomatal conductance (gs), transpiration (E),
and specific leaf area (
31. Driessche, R.v.-d. 1992b. Changes
in drought resistance and rootgrowth capacity of container seedlings in
response to nursery drought, nitrogen, and potassium treatments.
Canadian-Journal-of-Forest-Research 22(5):740-749.
Keywords: nursery operations
nursery fertilization
tree/stand protection
tree/stand health
growth
carbon allocation
tree physiology
Abstract: Douglas
fir (Pseudotsuga menziesii), lodgepole pine (Pinus contorta), and white spruce
(Picea glauca) seedlings, each represented by two seed lots, were grown in
Styroblock containers in a greenhouse and plastic shelter house from February
1989 to January 1990. The seedlings were exposed to two N treatments (20 and
200 mg/litre) and three K treatments (5, 25 and 100 mg/litre) arranged
factorially within three drought treatments. After winter storage, seedlings
from a complete set of treatments were planted into hygric, mesic and xeric
sand beds during 12-14 March. Increasing nursery drought stress increased
survival of Douglas fir and lodgepole pine after planting,
and high N treatment level increased survival of lodgepole pine and white
spruce. Under xeric conditions, combined nursery drought and high N treatments
increased survival of lodgepole pine by 33%, indicating the importance of
nursery cultural regime for stock quality. Increase in nursery drought stress
did not decrease seedling size by much; increase in N increased seedling size
one season after planting. A positive relation between shoot
: root ratio and survival in lodgepole pine and white spruce indicated
that increase in N increased both shoot growth and drought resistance over the
N range investigated. Only Douglas fir showed an interaction between drought
and N treatment and a small response in both survival and dry weight to K
application. Root growth capacity, measured at the time of planting, showed an
approximate doubling in all species due to high N treatment, and was also
increased in white spruce by drought stress. Survival and root growth capacity
were poorly correlated, but dry-weight growth in sand beds was well correlated with
root growth capacity. Shoot dry weight and percentage N in shoots measured
after nursery growth were correlated with root growth
capacity. Manipulation of root growth capacity by changing nursery treatment
was possible without altering resistance to drought stress after planting.
32. El Kassaby, Y.A., D.G.W.
Edwards and C. Cook.
1990a. Impact of crop management practices on seed yield in a Douglas-fir seed
orchard. Silvae-Genetica 39(5-6): 226-230.
Keywords: seed orchard management
tree/stand protection
reproduction
tree/stand health
Abstract: The
impact of two crop-management practices, supplemental mass pollination (SMP)
and overhead cooling, on seed yield in a 13-yr-old Douglas fir (Pseudotsuga
menziesii) seed orchard was studied in Saanichton, British Columbia. A 2x2
factorial trial of SMP/no SMP and cooling/no cooling was applied. There were no
significant differences in potential seed yield per cone, average number of
successful fertilizations, and average number of filled seeds per cone between
cooling or SMP treatments or combinations. Results indicated that
within-orchard pollen cloud was not a factor limiting seed yield. Average
number of seeds infested by the Douglas fir seed wasp (Megastigmus
spermotrophus) larvae was significantly (P<0.05) less when cooling was
applied, indicating that the treatment was effective in disrupting the
synchrony between the presence of ovipositing females and developing cones.
33. 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.
34. Erickson, R.D. 1995. Douglas-fir tussock moth. In
Keywords: tree/stand protection
tree/stand health
Abstract: The
recognition, biology, host plants, injuriousness, distribution and control of
the lymantriid Orgyia pseudotsugata, especially on Douglas fir (Pseudotsuga
menziesii), in
35. Fashler, A.M.K. and Y.A.
El-Kassaby. 1987. The effect of water spray cooling
treatment on reproductive phenology in a Douglas-fir seed orchard.
Silvae-Genetica 36(5-6): 245-249.