1. 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
2. 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.
3. 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.
4. 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
5. Folk, R.S., S.C. Grossnickle, P. Axelrood and D.
Trotter. 1999. Seed lot, nursery, and bud dormancy effects on root electrolyte
leakage of Douglas-fir (Pseudotsuga menziesii) seedlings. Canadian-Journal-of-Forest-Research
29(8): 1269-1281.
Keywords: nursery operations
tree physiology
tree/stand health
photosynthesis
growth
tree phenology
Abstract: The effects
of seed lot, nursery culture, and seedling bud dormancy status on root
electrolyte leakage (REL) of Douglas-fir (Pseudotsuga
menziesii) seedlings were assessed to determine if
these factors should be considered when interpreting REL for seedling quality.
The relationships of REL to survival, net photosynthesis (Pn),
stomatal conductance (gwv)
mid-day shoot water potential ( Psi
mid), root growth capacity (RGC), and relative height growth were determined
for each factor in experiments in 1994-95 in nurseries in
6. 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.
7.
Keywords: release treatments
chemical release
growth
tree physiology
soil properties
photosynthesis
Abstract: The
growth of Douglas fir Pseudotsuga menziesii
seedlings was increased during the first 5 years by controlling grasses and
forbs in 7 herbicide regimes during the 1st 3 years, the effect diminishing
with time after planting. Devegetated plots had more
available moisture through the growing season than those with Agrostis tenuis or mixed mixed grass/forb cover dominated
by A. tenuis or Hypochaeris
radicata. Tree moisture stress followed soil moisture
but only after allowing for large fluctuations of diurnal stress. Weed control
relieved moisture stress in trees. P. menziesii
photosynthesis tended to shut down in the region of -2.0 MPa
moisture stress. For the 1st 3 years in a favourable
coastal environment approx. 1700 MPa-h above -2.0 MPa was estimated to be required for survival. Increments
of moisture beyond that would contribute significantly to growth.
8. Parke, J.L., R.G. Linderman and C.H. Black. 1983a. The
role of ectomycorrhizas in drought tolerance of
Douglas-fir seedlings. New-Phytologist 95(1): 83-95.
Keywords: nursery operations
tree/stand protection
photosynthesis
tree physiology
mycorrhizal response
Abstract: Pseudotsuga menziesii seedlings were watered daily or conditioned to
cyclic drying and re-wetting of the soil. Net photosynthesis rates of mycorrhizal and non-mycorrhizal
seedlings watered daily were similar but drought-stressed mycorrhizal
seedlings fixed CO2 at a rate 10 times that of non-mycorrhizal
ones. Total leaf water potentials of mycorrhizal
plants were lower than those of non-mycorrhizal
plants but they recovered more rapidly. Non-mycorrhizal
seedlings and those inoculated with 4 ectomycorrhizal
fungi were allowed to dry, then re-watered and compared for their ability to
tolerate and recover from drought. Those inoculated with Rhizopogon
vinicolor were the least affected by drought. Net
photosynthetic rate of R.-inoculated seedlings 24 h after re-watering was 7
times greater than that of non-mycorrhizal seedlings.
The transpiration rate of R.-inoculated seedlings was low before desiccation,
declined rapidly during the drought period and, after re-watering, quickly
resumed a rate higher than that for other treatments.
9. Prasad, R. 2000. Some aspects of the impact and management of the exotic weed,
Scotch broom (Cytisus scoparius
(L.) Link) in
Keywords: release treatments
manual release
growth
photosynthesis
Abstract: A
recent cutover area near
10. Price, D.T., T.A. Black and F.M. Kelliher. 1986. Effects of salal understory removal on photosynthetic rate and stomatal conductance of young Douglas-fir trees.
Canadian-Journal-of-Forest-Research 16(1): 90-97.
Keywords: release treatments
manual release
photosynthesis
tree physiology
soil properties
growth
Abstract: Studies
were made in a thinned 32-yr-old Douglas fir stand on a drought-prone site on
the E. coast of
11. Turner, J. and S.J. Mitchell.
2003. The effect of short day treatments on containerized Douglas-fir
morphology, physiology and phenology. New-Forests
26(3): 279-295.
Keywords: nursery operations
growth
tree morphology
tree physiology
photosynthesis
tree phenology
Abstract: The
effect of short day treatments ('blackout') on Douglas-fir (Pseudotsuga
menziesii (Mirb.) Franco) container seedlings at the time of lift
and following cold storage was investigated. Variables measured
included height, root collar diameter (RCD), root growth capacity (RGC),
photosynthetic efficiency after -18 degrees C freezing (PEF), and days to
terminal bud break (DBB). From one to four blackout dormancy induction
treatments were started on three dates (July 12, July 26, and August 10) with
10 or 20 d between multiple blackouts. Increasing the number of blackout
treatments resulted in lower RCD, lower DBB in the late winter/early spring, and higher PEF in the early
fall. Later blackout start dates decreased PEF in the early fall, and increased
overall height and late fall RGC as compared to earlier blackout start dates.
Nurseries growing Douglas-fir seedlings from coastal
12. Woodruff, D.R., B.J. Bond, G.A.
Ritchie and W. Scott. 2002. Effects of stand density on the growth of young
Douglas-fir trees. Canadian-Journal-of-Forest-Research 32(3): 420-427.
Keywords: planting operations
growth
photosynthesis
tree physiology
Abstract: The objectives
of this study were (i) to provide further evidence of
a positive correlation of stand density with early growth of coastal
Douglas-fir (Pseudotsuga menziesii
(Mirb.) Franco var. menziesii);
(ii) to determine when after planting the positive growth response occurs and
how long it lasts; and (iii) to use stable isotopes of carbon to test whether
the mechanism(s) responsible for the positive growth response to density are
related to variables affecting photosynthesis, such as
nutrient or moisture availability. We measured annual height (h) and diameter
(d) growth (retrospectively) of 8- and 12-year-old trees in initial planting
densities of 300, 1360, and 2960 trees/ha. Both height and diameter growth
increased with density through the fifth year after planting and decreased with
density by year 7. Diameter squared x height (d2h) was used as a volume index
to assess increase in tree volume. Second-year increase in d2h for the
high-density treatments was 300% of that in the low-density treatments. The delta
13C values of wood cellulose from annual rings of the second and third years
after planting were not significantly different among densities, suggesting
either (i) no significant differences in the effects of water availability,
nutrient availability, or source air on photosynthesis in the three density
treatments or (ii) differences that produced no net effect on delta 13C.
13. Zhang, J.W., J.D. Marshall and
B.C. Jaquish. 1993. Genetic differentiation in carbon
isotope discrimination and gas exchange in Pseudotsuga
menziesii. A common garden
experiment. Oecologia 93(1): 80-87.
Keywords: genetic tree improvement
photosynthesis
tree physiology
Abstract: Seeds
were collected in 1966 from 25 naturally regenerated Douglas fir (Pseudotsuga menziesii) stands
across its range in the USA and Canada (from 33 degrees 30' N to 53 degrees 12'
N), from 170 m to 2930 m altitude, and from coastal and interior sites. Seeds
were sown in spring 1972, and at 3 yr old seedlings were transplanted to the