1. Cole, E.C. and M. Newton. 1989a. Height growth response in
Christmas trees to sulfometuron and other herbicides.
Proceedings-of-the-Western-Society-of-Weed-Science (Vol. 42): 129-135.
Keywords: release treatments
chemical release
growth
tree/stand health
stand conditions
Abstract: Abies
procera, A. grandis and Pseudotsuga menziesii cv. Menziesii were evaluated for
tolerance to sulfometuron (0.05-0.21 kg/ha), atrazine (4.5 kg/ha) and
hexazinone (2.2 kg/ha). Herbicides were applied pre-budbreak and sulfometuron
was also applied post-budbreak. Weeds were suppressed equally effectively by
all rates and herbicides pre-em. Low rates of sulfometuron were less effective
post-em. There was no significant damage to A. procera seedlings, although the
highest rate of sulfometuron slowed growth significantly. A. grandis was not
affected by any treatment. All treatments caused injury to 1-year-old P.
menziesii, primarily needle chlorosis and slight stunting. Growth was best in
atrazine-treated plots. For 3-year-old P. menziesii, injury was not significant
but high rates of sulfometuron caused cosmetic damage. Best growth was observed
with hexazinone and worst with sulfometuron. Post-budbreak applications and
high rates of sulfometuron reduced growth more than pre-budbreak application
and low rates.
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2. Cole, E.C. and M. Newton. 1989b. Seasonal efficacy comparison of two glyphosate formulations.
Proceedings-of-the-Western-Society-of-Weed-Science (Vol. 42): 136-142.
Keywords: release treatments
chemical release
tree/stand health
stand conditions
Abstract:
Glyphosate formulations with 13% (Roundup) and without (Accord) surfactant were
compared at 0.84 and 1.68 kg/ha, applied June-Oct. against Alnus rubra, Rubus
spectabilis, R. parviflorus, R. ursinus and Pteridium
aquilinum in a Pseudotsuga menziesii cv. menziesii plantation. No differences
in efficacy between the two formulations against any species were noted. All
species were controlled better by high rates of herbicide. R. spectabilis and
R. parviflorus were controlled <less or =>100%, although July
applications were least effective. A. rubra was reduced <less or =>80%
and early application gave best control. Rates of application had less effect
on Pteridium aquilinum control (<less or =>98%), and Oct. applications
were least effective. Damage to Pseudotsuga menziesii was worst with June
applications and decreased through the year. Oct. treatment caused negligible
damage.
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3. Cole, E.C., M. Newton and D.E.
White. 1986. Response of northwestern hardwoods, shrubs, and Douglas-fir to
Arsenal and Escort. Proceedings-of-the-Western-Society-of-Weed-Science
(Vol.39): 93-101.
Keywords: release treatments
chemical release
tree/stand health
stand conditions
Abstract: Arsenal
(imazapyr) and DPX-T6376 (metsulfuron) were evaluated for scrub control in
Pseudotsuga menziesii plantations at 3 sites in Oregon in 1984-85. Arsenal produced the most complete and
consistent control of Acer macrophyllum when applied in late summer, but early
summer applications were more effective against the sclerophyll brush species
Arbutus menziesii, Ceanothus velutinus var. laevigatus, Arctostaphylos
columbiana and A. viscida. High rates of Arsenal gave good control of Alnus
rubra and Rubus spectabilis, but did not control R. laciniatus or R. procerus.
On all the controlled species, growth of new foliage was decreased or
prevented. DPX-T6376 reduced the crown vol. of A. macrophyllum and killed the
sclerophyll brush species, all Rubus spp. but not A. rubra. Both chemicals
produced severe injury to P. menziesii.
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4. Cole, E.C., M. Newton and D.E.
White. 1988. Efficacy of imazapyr and metsulfuron methyl for site preparation
and conifer release in the Oregon Coast Range. Forest-Research-Laboratory,-Oregon-State-University Research-Note 81. 7 p.
Keywords: release treatments
chemical release
tree/stand health
stand conditions
Abstract: Imazapyr
(Arsenal) and metsulfuron methyl (Escort) were tested at 3 rates for
controlling shrubs in young Douglas fir (Pseudotsuga menziesii) plantations on
3 sites in the Oregon Coast Range. Imazapyr was highly effective on red alder (Alnus rubra)
and bigleaf maple (Acer macrophyllum), but was less effective on salmonberry
(Rubus spectabilis) and other blackberry (Rubus) species. Metsulfuron-methyl
was ineffective on red alder and bigleaf maple, but gave excellent control of
salmonberry, Himalaya blackberry (R. procerus) and evergreen blackberry (R.
laciniatus). Both chemicals caused severe injury to Douglas fir seedlings,
especially when applied during the growing season. It is concluded that these
herbicides are promising for site preparation, but have limited use for release
of Douglas fir.
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5. DeBell, D.S. and T.C.
Turpin. 1989. Control
of red alder by cutting. Pacific-Northwest-Research-Station,-USDA-Forest-Service Research-Paper PNW-RP-414. ii + 10 p.
Keywords: release treatments
manual release
stand conditions
Abstract: Effects
of tree age, month of cutting, and height and angle of the cut on sprouting of
red alder (Alnus rubra) stumps were evaluated in a study designed to develop an
effective method for controlling red alder in Douglas fir (Pseudotsuga
menziesii) plantations in the Oregon Coast Range.
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6. Dimock, E.J., II and E.B. Collard.
1981. Postplanting sprays of dalapon and atrazine to aid conifer establishment.
Pacific-Northwest-Forest-and-Range-Experiment-Station,-USDA-Forest-Service Research-Paper PNW-RP-280. iii + 16 p.
Keywords: release treatments
chemical release
growth
tree/stand health
stand conditions
Abstract: A
mixture of dalapon and atrazine at 8 and 4 lb/acre, respectively, or dalapon or
atrazine alone were applied to control perennial grasses and forbs competing
with newly planted seedlings of ponderosa pine and Douglas fir. In 4 studies in
Oregon in 1975, herbicides were spot sprayed around individual
seedlings. In 2 studies in Washington and Oregon in 1976, herbicides were broadcast sprayed. The mixture
consistently controlled grass and forbs better than either herbicide alone,
reducing grass and forb cover respectively by 80-82% and 48-58% in the first
year. Control persisted for 2-4 yr. Varying results are reported as to the
effects of the different treatments on height growth and survival.
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7. Drever, C.R. and K.P. Lertzman.
2003. Effects of a wide gradient of retained tree structure on understory light
in coastal Douglas-fir forests. Canadian-Journal-of-Forest-Research 33(1):
137-146.
Keywords: thinning
stand conditions
Abstract: We
characterize understorey light of seven stands that varied along a gradient of
tree retention. Using hemispherical canopy photographs and digital image, we
estimated gap light or solar radiation reaching the understorey through the
canopy. Using nonlinear regressions, we related gap light to several structural
attributes in the examined silvicultural treatments. The silvicultural
treatments affected both the median and range of gap light in the understorey.
As overstorey removal increased from uncut second growth to green-tree
retention, the median value of light increased from 8 to 68% full sun, while
the range of light increased from 3-22% to 26-88% full sun. We found strong,
significant, and negative nonlinear relationships between gap light at a
particular microsite (0.04 ha) in the understorey and the height, diameter at
breast height, density, and volume of surrounding retained trees
(ra2=0.77-0.94). These relationships can aid planning of treatments that retain
forest structure, such as variable retention, by allowing predictions of
understorey light from commonly used field data. These predictions allow forest
managers to understand some of the ecological consequences and tradeoffs
associated with retaining structure during harvesting.
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8. Feller, M.C. 1990. Herbicide application
followed by prescribed fire to convert a brushfield into a conifer plantation
in south coastal B.C.: a combination of the initial effects of two treatments. B.C. Ministry of Forests FRDA Report 146. 40
p.
Keywords: site preparation
chemical preparation
prescribed fire
growth
tree/stand health
soil properties
stand conditions
Abstract: A field
study was carried out in Pseudotsuga menziesii stands in British Columbia, Canada, to investigate the effects on vegetation of glyphosate
applications in September 1987 or July 1988, followed by burning in October
1988. Results did only show slight differences between treatments.
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9. Figueroa, P.F. 1989. Bigleaf maple
control: triclopyr thin-line and spot-foliar application treatments using
imazapyr, metsulfuron, and glyphosate.
Proceedings-of-the-Western-Society-of-Weed-Science (Vol. 42): 104-119.
Keywords: release treatments
chemical release
stand conditions
economics
Abstract: Field
trials were conducted to compare the efficacies of March applications of
triclopyr thin-line +or- 1 kg/ha Mor-act or 2,4-D
(1:1) with June spot-foliar applications of 0.6 or 1.1 kg/ha imazapyr, 0.170
kg/ha metsulfuron and 6.7 kg/ha glyphosate to control Acer macrophyllum in a
Pseudotsuga menziesii plantation. All thin-line treatments gave 80% control 2
years later; complete sanding was hindered by stems growing along the ground.
Dilution did not affect control. Spot-application success depended on degree of
crown coverage. metsulfuron and glyphosate were not
effective, but imazapyr control reached 60-70% 2 years after treatment. Only
triclopyr and full coverage imazapyr suppressed A. macrophyllum growth to below
the height of P. menziesii. Crown volume was held to pre-treatment levels with
metsulfuron and glyphosate but decreased with imazapyr. The two treatment
methods tested are potentially cost-effective; triclopyr costs are higher but
spot-application carries higher labour costs. Application rates of 2 ml
triclopyr/ Msuperscript 2 crown area will give 100% control if all stems are
banded; with delivery rates of 59 ml/clump a 45% solution can be used.
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10. Figueroa, P.F. 1991. Ground
applied herbicide methods for red alder control: herbicide efficacy, labor
costs, and treatment method efficiency. In
Proceedings-of-the-Western-Society-of-Weed-Science,12-14-March-1991.
pp. 44: 53-68.
Keywords: release treatments
chemical release
economics
stand conditions
Abstract: A study
was conducted to develop the cost estimates for ground-applied manual control
methods in variable density red alder [Alnus rubra] stands and to evaluate the
efficacy of the various herbicide formulations for each system. Field trials
were initiated in 3 Douglas fir [Pseudotsuga menziesii] plantations located on
Weyerhaeuser Company land located in SW Washington. Two 6-year-old plantations had streamside buffer zones
remaining from the previous year's operational herbicide spray programme; the
3rd was a 13-year-old plantation which had not been previously treated with
herbicides to control A. rubra. The treatments tested were as follows: 50%
triclopyr, 45% glyphosate and 10% imazapyr applied to the cut stump surface;
low-vol. basal application of 5, 10 and 15% triclopyr and 2 and 4% imazapyr;
thin-line application of 50, 75 and 100% triclopyr and 20 and 40% imazapyr;
stream-line application of 10, 30 and 50% triclopyr and 4 and 20% imazapyr;
hack-and-squirt application with imazapyr applied to 1 cut at 0.25, 0.5 and
0.75 ml and to 2 cuts at 0.25 and 0.5 ml; and capsule injection of 1 or 2
glyphosate capsules. A discussion of the results is presented and total
treatment costs are given. It is concluded that ground application treatments
have advantages over aerially applied treatments, including being useful for
the treatment of areas of public sensitivity and when other environmental risks
need to be minimized.
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11. Figueroa, P.F. 1993. Efficacy and
cost of ground-applied herbicide methods for red alder control. Down to Earth
48(1): 6-10.
Keywords: release treatments
chemical release
stand conditions
growth
tree/stand health
Abstract: The
effects on red alder [Alnus rubra] mortality, diam. at breast height and
height, and any phytotoxic effects to Douglas fir [Pseudotsuga menziesii] of
Garlon 4 (triclopyr) at 4 lb/gallon and Chopper EC (imazapyr) at 2 lb, applied
by stream line, thin line and low vol. treatments, and of Garlon 3A (triclopyr)
at 3 lb, Roundup (glyphosate) at 3 lb and Arsenal (imazapyr) at 4 lb applied by
cut stump treatment were evaluated in streamside buffer zones in two 6-year-old
P. menziesii plantations in SW Washington. All treatments resulted in good
control of A. rubra, but the most cost-effective control was achieved by the
stream line application of Garlon 4, followed by low vol. basal or thin line
treatments of Garlon 4 and cut stump treatment with 50% Garlon 3, 45% Roundup
and 10% Arsenal. Negligible P. menziesii damage was caused by cut stump
treatments, but damage occurred with basal-bark treatments although Garlon 4
generally caused less injury than Chopper EC.
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12. Figueroa, P.F. and V.F.
Carrithers. 1993. Bigleaf maple control: thinline basal applications using
triclopyr and triclopyr plus picloram. In Proceedings-of-the-Western-Society-of-Weed-Science,
9-11-March-1993. pp. 46: 24-30.
Keywords: release treatments
chemical release
stand conditions
economics
Abstract: A field
trial was conducted at Mt. St. Helens Tree Farm, Cowlitz county, Washington, in
1988-91 to determine the min. threshold level of herbicide needed to control
bigleaf maple [Acer macrophyllum] stump sprouts in Douglas fir [Pseudotsuga
menziesii]. Garlon (triclopyr) at 0.24-3 lb/gal was applied on 6 Dec. 1990, 6 Feb. 1991 and 11 Apr. 1991, and triclopyr + picloram at 1 + 0.5 lb was
applied on 6 Feb. 1991 using thinline applications to the entire circumference of
each stem in the bigleaf maple clump. The threshold level of Garlon for
<more or =>90% control was found to be between 1.1 and 1.7
ml/msuperscript 2 of crown area. Most treatments produced clumps that appeared
to be dead during the 1st year but which resprouted in the 2nd year; it is
suggested that such inconsistencies in mortality among treatments are due to
the inability to completely band every stem. Economic considerations for
herbicide costs are discussed.
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13. Harrington, T.B., J.C. Tappeiner,
II and T.F. Hughes. 1991. Predicting average growth and size distributions of
Douglas-fir saplings competing with sprout clumps of tanoak or Pacific madrone.
New-Forests 5(2): 109-130.
Keywords: release treatments
manual release
growth
stand conditions
Abstract: Average
growth and size distributions of 3- to 6-year-old (in 1983) Douglas fir
(Pseudotsuga menziesii) saplings in three plantations in SW Oregon were studied
for 7 years (1983-1989) after thinning of associated sprout clumps of tanoak
(Lithocarpus densiflorus) or Pacific madrone (Arbutus menziesii); in some cases
shrubs and herbs were also suppressed. Biologically based nonlinear equations
explained 66, 90, and 53% of variation in average annual increment of Douglas
fir height, diameter-squared, and crown cover, respectively. Equations for
annual increment of crown cover of broadleaved and understorey vegetation
explained only 10 to 12% of the variation, because these parameters exhibited a
high degree of variability. Model simulations demonstrated that, for the same
initial levels of cover, tanoak had faster rates of crown cover growth than
madrone and also caused greater limitations in Douglas fir growth. Suppression
of shrubs and herbs increased growth of Douglas fir only when broadleaved
species were absent. Weibull functions adequately described size distributions
for Douglas fir in 92% of individual-tree data sets. Regression functions of
broadleaved crown cover and average Douglas fir size explained 51, 93, and 24%
of variation in the Weibull A, B, and C parameters, respectively. Model
simulations with predicted Weibull parameters demonstrated that broadleaved
competition caused a positive skewing in size distributions for height and stem
diameter of Douglas fir.
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14. Harrington, T.B., R.G. Wagner,
S.R. Radosevich and J.D. Walstad. 1995. Interspecific competition and herbicide
injury influence 10-year responses of coastal Douglas-fir and associated
vegetation to release treatments. Forest-Ecology-and-Management 76(1/3): 55-67.
Keywords: release treatments
chemical release
manual release
growth
tree/stand health
tree physiology
stand conditions
Abstract:
Responses of competing vegetation and planted Douglas fir (Pseudotsuga
menziesii var. menziesii) were studied for 10 years after six herbicide and
manual release treatments in the Washington and Oregon Coast Ranges. Studies
were installed in six 2- or 3-yr-old plantations, with Douglas fir densities of
988 to 1482 plants/ha at time of planting and 721 to 1282/ha 2 to 3 years late.
Research objectives were to quantify regional, long-term responses of
vegetation (Douglas fir and non-coniferous species) to various levels of
competition, light and soil water availability, and intensity versus importance
of factors influencing Douglas fir growth. Three treatments reduced shrub cover
relative to the untreated check: triclopyr in year 1, glyphosate in years 1-5,
and repeated control (via several herbicide applications) in years 1-10.
Reductions in woody cover from glyphosate stimulated increases in herb cover in
years 3 and 5, while repeated control reduced herb cover in years 1, 2 and 5.
Through year 10, Douglas fir survival (86-99%) varied little among treatments.
Visual symptoms of herbicide injury to Douglas fir from triclopyr (45% of
trees) and glyphosate (17% of trees) were associated with 0.1-0.2 m reductions
in first-year height. After adjusting for tree size, Douglas fir growth in stem
basal area 2 years after triclopyr was less than that of the untreated check,
suggesting prolonged effects of herbicide injury. Because it sustained low
levels of interspecific competition, caused minimal tree injury, and prevented
overtopping cover from red alder (Alnus rubra), repeated control was the only
treatment in which Douglas fir size (9.8 m height and 21 cm basal diameter in
year 10) significantly exceeded (P<less or =>0.02) that of the untreated
check (7.8 m height and 12 cm diameter).
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15. Hedin, I.B. 1994. Mechanical site
preparation on salal-dominated sites: five-year results.
Forest-Engineering-Research-Institute-of-Canada
Keywords: site preparation
mechanical preparation
growth
stand conditions
Abstract: Trials
began in 1987 on sites on Vancouver Island where salal (Gaultheria shallon) is a competitor to
Douglas fir [Pseudotsuga menziesii]. Three equipment types were tested: the
Mitsui Miike (an excavator-mounted rock grinding attachment), the TTS Delta
disc trencher and an excavator with a ripper tooth and live thumb. All three
mechanical site preparation treatments were equally effective at reducing the
coverage of salal and other competing vegetation and improving Douglas fir
growth performance. On sites where the disc trencher can operate, with gentle
slopes and light to moderate slash, it is most cost effective because of
greater productivity.
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16. Hedlin, A.F., J. Weatherston,
D.S. Ruth and G.E. Miller. 1983. Chemical lure for male Douglas-fir cone moth,
Barbara colfaxiana (Lepidoptera: Olethreutidae). Environmental-Entomology
12(6): 1751-1753.
Keywords: tree/stand protection
stand conditions
Abstract: Field
trapping in British Columbia indicated that males of Barbara colfaxiana
(Kearfott), the larvae of which feed in the cones of Pseudotsuga menziesii and
damage the seeds, were attracted to mixtures of (Z)-9-dodecen-1-ol and
(Z)-9-dodecenyl acetate. Most blends of these compounds were attractive to some
extent, but blends containing 15 to 50% acetate were the most consistently
attractive.
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17. Helgerson, O.T. 1990b. Response of underplanted Douglas-fir to herbicide injection of
sclerophyll hardwoods in southwest Oregon.
Western-Journal-of-Applied-Forestry 5(3): 86-89.
Keywords: nursery operations
release treatments
chemical release
stand conditions
tree physiology
tree/stand health
growth
Abstract:
Low-value broadleaf sclerophyll forests in SW Oregon, typically composed of tanoak (Lithocarpus densiflorus),
Pacific madrone (Arbutus menziesii) and chinkapin (Castanopsis chrysophylla),
may be converted to commercially valuable Douglas fir (Pseudotsuga menziesii)
by underplanting. Results are given of studies of container-grown plug and
nursery-grown bareroot fir seedlings planted out in March 1983 on plots in
which all broadleaf stems had been previously (September 1981) injected with triclopyr
amine. Although 60% broadleaf cover was killed by injection, 7 years later
ground cover was significantly greater on these treated plots because of
sprouting. Seedlings planted beneath treated broadleaf trees experienced
greater daytime, but less predawn, moisture stress; plugs survived better than
bareroots; and survival of seedlings on treated plots was not significantly
better until 2 years after planting. Herbicide injection also resulted in
increased height, diameter and volume growth rates of Douglas fir seedlings,
and is recommended for the establishment of a conifer stand.
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18. 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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19. Hobbs, S.D. and K.A. Wearstler, Jr. 1985. Effects of cutting
sclerophyll brush on sprout development and Douglas-fir growth.
Forest-Ecology-and-Management 13(1/2): 69-81.
Keywords: release treatments
manual release
stand conditions
tree physiology
growth
Abstract: In SW Oregon, varying amount of brush were
removed from a sclerophyll brushfield dominated by Quercus chrysolepis and
Arctostaphylos patula with scattered Pseudotsuga menziesii saplings. Brush
removal was accomplished by slashing (cut by chainsaw) near ground level at
three intensities: (1) total removal, (2) partial removal, and (3) an untreated
control. Sclerophyll brush species responded within 3 weeks of slashing by
vigorous sprouting, which was greatest in total brush removal areas where 861 513
sprout stems/ha developed during the first year. Soil water potentials and
predawn xylem pressure potentials of Douglas fir were less negative in total
removal areas than in partial removal and untreated control areas. Relative
growth rates of Douglas fir saplings temporarily increased in total and partial
brush removal areas, but were not significantly different from the untreated
control 3 yr after treatment. Slashing of sclerophyll brush to release
long-suppressed Douglas fir is not recommended because of rapid brush recovery
by sprouting.
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20. Huffman, D.W. and J.C. Tappeiner,
II. 1997. Clonal expansion and seedling recruitment of Oregon grape (Berberis
nervosa) in Douglas-fir (Pseudotsuga menziesii) forests: comparisons with salal
(Gaultheria shallon). Canadian-Journal-of-Forest-Research 27(11): 1788-1793.
Keywords: thinning
stand conditions
Abstract: Seedling
regeneration and morphology of Oregon grape (Berberis nervosa) and salal
(Gaultheria shallon) were studied in thinned and unthinned Douglas fir
(Pseudotsuga menziesii) stands in the central Coast Range, Oregon. Above- and below-ground growth of both
species were significantly and negatively correlated with stand density.
Oregon grape appears to have less potential for vegetative spread than does
salal. It produced two to three times fewer rhizome extensions, and rhizome
extensions were only half as long as those of salal. Oregon grape seedlings
were common in areas of moss ground cover among patches of the two species.
Salal seedlings were restricted to decaying logs. Seedling densities of Oregon
grape in thinned stands were more than six times those in unthinned stands. For
Oregon grape, understorey establishment is accomplished by seedling
establishment and recruitment of new genets. In contrast, salal maintains
itself in forest understories primarily through vegetative growth, since its
seedling establishment is restricted mainly to decayed wood. Continual
recruitment of new aerial stems or ramets enables Oregon grape to maintain a dense
cover once it is established in the understorey.
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21. Huffman, D.W., J.C. Tappeiner, II
and J.C. Zasada. 1994. Regeneration of salal (Gaultheria shallon) in the central
Coast Range forests of Oregon. Canadian-Journal-of-Botany 72(1): 39-51.
Keywords: thinning
stand conditions
Abstract: Regeneration
of salal (Gaultheria shallon) by seedling establishment and vegetative
expansion was examined in Douglas fir (Pseudotsuga menziesii) stands that had
been thinned, clear felled or undisturbed in the central Coast Range of Oregon.
Size and expansion rate of individual clonal fragments were negatively
correlated with overstorey stand density (p <less or =>0.039). As overstorey
basal area increased from 25 to 75 msuperscript 2/ha, mean annual growth
percentage of clone rhizome systems decreased from 23.7 to 0% and mean total
rhizome length decreased from 102 to 0.89 m. Interclonal competition in dense
clumps of salal apparently caused rhizomes to die and clones to fragment. In
these patches, rhizome biomass and density, aerial stem biomass and density,
and total biomass of G. shallon were negatively correlated with overstorey
density (p <less or =>0.01). In clear fellings, salal clumps had up to
177.7 m rhizome/msuperscript 2 and 346 stems/msuperscript 2, whereas patches
under dense overstories had as few as 10.6 m rhizome/msuperscript 2 and 19
stems/msuperscript 2. Aerial stem populations had uneven-age distributions in
all overstorey densities. This structure is apparently maintained through
annual production of new ramets. Salal seedling establishment rates were
significantly affected by study site location, overstorey density, and
substrate (p <less or =>0.05). Two-year survival was highest on rotten
logs and stumps in thinned stands.
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22. Hulme, M.A. and G.E. Miller.
1988. Potential for control of Barbara colfaxiana (Kearfott): (Lepidoptera:
Olethreutidae) using Trichogramma sp. Colloques de l'INRA (43): 483-488.
Keywords: tree/stand protection
stand conditions
Abstract: The
efficacy of Trichogramma minutum for the control of the tortricid Barbara
colfaxiana on Pseudotsuga menziesii was assessed. T. minutum was obtained from
the tortricid Choristoneura fumiferana in Ontario and reared through over 30 laboratory generations in eggs
of the gelechiid Sitotroga cerealella. B. colfaxiana eggs were readily
parasitized at 25 degrees C. About 3 million parasitized eggs glued to 100
cards were suspended throughout 19 trees (height 4 to 8 m) in British Columbia. Daytime shade temperatures during the following week
peaked at 15-20 degrees C. After 1 day, 6% of the parasitoids had emerged.
After 5 days, 54% of sampled parasitized S. cerealella eggs had emergence
holes, but eggs on half the cards had been eaten by formicids. Of the B.
colfaxiana eggs sampled, 2-4% were parasitized by T.
minutum, regardless of whether samples were on the same branch as the cards or
on remote branches. It is concluded that T. minutum can parasitize B.
colfaxiana in the field and that Trichogramma species which are adapted to B.
colfaxiana at temperatures of 15-20 degrees C are needed.
23. Humphreys, N. 1995. Douglas-fir
beetle in British Columbia. In Forest-Pest-Leaflet 14. Pacific-Forestry-Centre,-Canadian-Forest-Service.
Keywords: tree/stand protection
tree/stand health
stand conditions
Abstract: Notes
are provided on the recognition, detection, biology, injuriousness and control
of the scolytid Dendroctonus pseudotsugae on Douglas fir (Pseudotsuga
menziesii) (and occasionally western larch (Larix occidentalis)) in British Columbia. The damage caused is described under the headings gallery
system; effect on the tree; host susceptibility and attack pattern; association
with root disease (including Armillaria ostoyae, Phaeolus schweinitzii and
Phellinus weirii); and defoliation (by Choristoneura occidentalis and Orgyia
pseudotsugata). Control of D. pseudotsugae is discussed under the headings
preventive measures (including log and slash disposal, general logging
practices), remedial measures (which include the use of trap trees and
pheromones) and brood destruction (by burning and similar measures).
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24. Karl, M.G. and P.S. Doescher.
1993. Regulating competition on conifer plantations with prescribed cattle
grazing. Forest-Science 39(3): 405-418.
Keywords: release treatments
manual release
stand conditions
tree physiology
soil properties
Abstract: On
conifer plantations, competitive understorey vegetation often retards growth
and establishment of tree seedlings. Livestock grazing is one method of
controlling the understorey vegetation and increasing the availability of site
resources to tree seedlings. It was hypothesized that prescribed cattle grazing
ameliorates water stress of young tree seedlings by reducing root growth of
competing understorey species. On a Douglas-fir (Pseudotsuga menziesii) and
ponderosa pine (Pinus ponderosa) plantation in SW Oregon planted in 1986, seedling water stress was evaluated using
the pressure chamber technique and gravimetric soil water determinations in
1986-89. Root growth of orchardgrass (Dactylis glomerata), the major
understorey competing species, was quantified in 1988 and 1989 using the root
periscope/mini-rhizotron technique. Seedling water stress levels during spring
and summer were similar in cattle-grazed areas and ungrazed areas in 1986 to
1988, but in summer 1989, water stress was reduced significantly in the grazed
area. Soil water content was higher in the grazed area in 1989, especially at
the 10-20 cm soil depth. End of season (July) orchardgrass root growth in
grazed plots was 18% less in 1988 and 15% less in 1989 than root growth in
ungrazed plots. It is concluded that repeated cattle grazing of orchardgrass
reduced transpirational surface area and root growth sufficiently to increase
soil water availability to tree seedlings. Thus, prescribed cattle grazing on
conifer plantations can enhance seedling physiological status by acting as a
regulator of above- and belowground competition.
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25. Kelpsas, B.R. 1987. Seasonal
impacts of fluroxypyr and triclopyr on conifers and shrubs.
Proceedings-of-the-Western-Society-of-Weed-Science (Vol.40): 128-129.
Keywords: release treatments
chemical release
tree/stand health
stand conditions
Abstract: Release
of Pseudotsuga menziesii from Rubus spectabilis and Alnus rubra in a plantation
in the Pacific
Northwest could be
achieved by 1.12 kg fluroxypyr/ha applied in May at the early foliar stage
without appreciable long-term injury. P. menziesii tolerated 1.12 kg
triclopyr/ha but was severely damaged by 1.12 kg and 2.24 kg fluroxypyr when applied
during the dormant season in Mar. Both fluroxypyr and triclopyr were more
effective against A. rubra than R. spectabilis. Control of R. spectabilis with
triclopyr was marginal.
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26. Ketchum, J.S., R. Rose and B.
Kelpsas. 1999. Weed control in spring and summer after fall application of
sulfometuron. Western Journal of Applied Forestry 14:80-85.
Keywords: site preparation
mechanical preparation
chemical preparation
stand conditions
Abstract: This
study tested the residual spring and summer efficacy of sulfometuron after
applications in the autumn in second growth Douglas fir (Pseudotsuga menziesii)
with red alder (Alnus rubra) and bigleaf maple (Acer macrophyllum) forest sites
in the central Coast Range, Oregon, USA, which had been harvested in the summer. Sulfometuron alone
(S) and sulfometuron plus imazapyr and glyphosate (SIG) were applied to
vegetation on mechanically scarified sites and unscarified sites. The
applications were replicated each month throughout autumn 1994. Vegetation
cover was assessed in mid-June and mid-August 1995. The SIG treatment gave
better control of vegetation than the S treatment, although cover was
significantly lower for both herbicide treatments (9% to 54% for summed cover)
compared to the control site (64% to 104% for summed cover). On scarified
sites, the month of application, early or late autumn,
did not significantly influence the efficacy of either treatment. On
unscarified sites, however, applications of the SIG treatment later in autumn
were less effective than early autumn treatments. Results suggest that autumn
applications of sulfometuron are still effective in spring and may eliminate
the need to treat sites again in the spring in order to achieve effective weed
control.
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27. Ketchum, J.S., R. Rose and B.
Kelpsas. 2000. Comparison of adjuvants used in fall-release herbicide mixtures
for forest site preparation. Tree-Planters' Notes 49(3): 66-71.
Keywords: site preparation
chemical preparation
release treatments
chemical release
tree/stand health
stand conditions
Abstract: Tank mixes
of the herbicides imazapyr and glyphosate were applied at 3 rates with 3
adjuvants (LI-700Reg., Nu-Film-IRReg., Silwet L-77Reg.) over California hazelnut (Corylus cornuta var. californica), vine maple
(Acer circinatum), and brackenfern (Pteridium aquilinum var. lanuginosum) on a
2-year-old clearcut of Douglas fir (Pseudotsuga menziesii) in Oregon. The herbicide 2,4-D was applied at 3 rates with 2
adjuvants (HerbimaxReg., Nu-Film-IR) over greenleaf manzanita (Arctostaphylos
patula) on a 4-year-old Douglas fir clearcut in Oregon. Tank mixes of imazapyr
and glyphosate with LI-700 or Nu-Film-IR were sprayed at 3 rates over
1-year-old seedlings of Douglas fir on 2 sites in Oregon. The herbicide rate strongly influenced the percentage of
foliage injured and percentage of stems killed for all herbicide treatments.
The adjuvants evaluated did not influence efficacy of herbicide applications on
California hazelnut, vine maple, or brackenfern. Herbimax increased
visual foliar damage resulting from 2,4-D application
on greenleaf manzanita. Douglas fir foliage was damaged by the higher herbicide
rates; the damage was greater from Nu-Film-IR than from LI-700.
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28. Knowe, S.A. and W.I. Stein. 1995. Predicting the effects of site
preparation and protection on development of young Douglas-fir plantations.
Canadian-Journal-of-Forest-Research 25(9): 1538-1547.
Keywords: site preparation
release treatments
tree/stand protection
growth
tree morphology
tree/stand health
stand conditions
Abstract:
Diameter prediction models based on the Weibull distribution function and
stand-table projection models based on changes in relative diameter were
developed for 2- to 10-year-old Douglas fir (Pseudotsuga menziesii) plantations
in Oregon. Both modelling approaches incorporated the effects of
site preparation, animal protection, and competing vegetation. The diameter
distribution approach is appropriate when information on initial diameters is
not available. The stand-table projection approach may be applied when tree
diameters in a plantation are measured two or more growing seasons after
planting. At young ages, the stand-table approach provided more accurate
representation of observed diameter distributions than the diameter
distribution approach. At age 10 the two methods provided comparable diameter
distributions. The equations derived for predicting survival, height growth of
dominant trees, height-diameter relationships, and the development of woody vegetation
over time will facilitate the study and comparison of stand structure and
dynamics after various site-preparation and animal protection treatments.
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29. Knowe, S.A., W.I. Stein and L.J. Shainsky. 1997. Predicting growth
response of shrubs to clear-cutting and site preparation in coastal Oregon forests. Canadian-Journal-of-Forest-Research 27(2):
217-226.
Keywords: planting operations
site preparation
chemical preparation
mechanical preparation
prescribed fire
stand conditions
Abstract:
Cover-projection models were developed based on algebraic difference
formulations of an exponential-power function to describe shrub recovery and
development patterns following clear cutting, site preparation and Douglas fir
(Pseudotsuga menziesii) planting at 4 sites in the Siuslaw National Forest,
Oregon. The sites formed part of the Coastal Site Preparation Study initiated
in 1980, in which the effects were tested of 6 treatments on shrub growth
patterns. Treatments were: none other than scalping a 30-cm spot when each 2-0
seedling was planted (control); spot clearing by cutting to 15 cm height all
woody vegetation within a 1.2 m radius of the seedling; spraying with
glyphosate (2.52 kg a.e./ha) in early autumn 1980; broadcasting burning slash
in midsummer 1980; manually slashing all woody vegetation in June 1980 and
broadcast burning later in the summer; and spraying with picloram + 2,4-D
(Tordon 101) in May or June 1980 (at 1.49 + 5.97 kg a.e./ha) and broadcast
burning in the summer. Results on the development of Douglas fir and associated
vegetation to age 10 yr have already been reported for this study (Stein (1995)
Research Paper - Pacific Northwest Research Station, USDA Forest Service, No. PNW-RP-473; Knowe & Stein (1995) Canadian Journal of
Forest Research 25 (9) 1538-1547). The shrub cover-projection
models were developed by incorporating indicator variables into the model rate
and shape parameters for the recovery of 3 specific shrubs (salal, Gaultheria
shallon; thimbleberry, Rubus parviflorus; and salmonberry, Rubus spectabilis),
and all shrubs. For salal, the shape parameter included an adjustment for
burning treatments that delayed maximum cover by several years in comparison
with unburned treatments. The rate parameter in the thimbleberry model was
adjusted for burning treatments; maximum cover occurred about 2 yr earlier in
burned than in unburned treatments. Both rate and shape parameters in the
salmonberry model were adjusted for burning treatments; delayed established but
increased growth rate and less salmonberry cover are characteristic of burned
treatments compared with the unburned treatments. The rate and shape parameters
in the model for the shrub group included adjustments for burning treatments.
Overstorey removal fostered shrub development, whereas site preparation
treatments slowed and curtailed it. The final cover-projection models accounted
for 68-92% of the total variation in cover, with the adjustments for burning
accounting for 1.5-3.3% of the variation. The predicted growth patterns are
consistent with trends in site occupancy and published autecological
characteristics.
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30. Leininger, W.C. and S.H. Sharrow.
1987. Seasonal diets of herded sheep grazing Douglas-fir plantations.
Journal-of-Range-Management 40(6): 551-555.
Keywords: release treatments
tree/stand health
stand conditions
Abstract: The
seasonal diets of herded sheep grazing cutover Douglas-fir (Pseudotsuga
menziesii) forests in the Coast Range of Oregon were studied during 1981 and
1982. Both 4- to 6-year-old non-grass-seeded and 2-year-old grass-seeded
plantations were included. Sheep grazing was monitored in spring, summer and
late summer. Forage on offer ranged from 764 to 2459 kg/ha.
Vegetational composition of sheep diets varied by year,
season and plantation age class. Averaged over the 2 years of grazing,
graminoids and forbs were nearly equal, at about 40% each, in sheep diets in
older plantations. In contrast, diets of sheep in young grass-seeded
plantations averaged 70% graminoids and only 16% forbs. Ferns were a minor
component (<2%) of sheep diets in both plantation age classes. Browse
averaged 15 and 12% of sheep diets in old and young plantations, respectively.
Douglas-fir was most palatable to sheep in spring soon after bud break. It was
generally avoided, however, and never comprised more than 3% of sheep diets.
Results suggest that sheep can be most effectively used for biological control
of unwanted brush species during summer and late summer when differences in
relative preference indices for target brush species and Douglas-fir are
greatest.
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31. Lindsey, G.D. and J. Evans. 1983.
Evaluation of zinc phosphide for control of pocket gophers on Christmas tree
plantations. Tree-Planters' Notes 34(2): 11-14.
Keywords: tree/stand protection
tree/stand health
stand conditions
Abstract: In
laboratory tests, pocket gophers (Thomomys and Geomys spp.) were offered 5
kinds of treated bait, including 1% Zn phosphide in oats, 0.75% Zn phosphide in
fresh carrots, and 0.5% strychnine in rolled oats (3 mixtures). The carrot bait
was found to be as effective for killing gophers as the strychnine mixtures.
Plots in a 4-yr-old Pseudotsuga menziesii and Pinus monticola plantation in Washington, with occupied T. mazama burrows, were baited with the
carrot or one of the strychnine mixtures in Nov. 1981. Both baits produced only
a 63% reduction in gopher activity, possibly because of the availability of
abundant alternative vegetative food. It was estimated that tree mortality due
to root pruning by gophers was >10% on this site. It is recommended that the
carrot/Zn sulphide bait be registered for special local needs where safety to
wildlife and domestic animals is important.
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32. Mason, R.R. and B.E. Wickman.
1991. Integrated pest management of the Douglas-fir tussock moth.
Forest-Ecology-and-Management 39(1-4): 119-130.
Keywords: tree/stand protection
tree/stand health
stand conditions
growth
Abstract: The
Douglas-fir tussock moth (Orgyia pseudotsugata) is one of the most destructive
forest defoliators of Douglas fir (Pseudotsuga menziesii), grand fir (Abies
grandis) and white fir (A. concolor) in western North America. An outline is given of current pest-management programmes
used in Oregon, which emphasize the annual monitoring of insects in
forests with outbreak histories to determine early changes in population
numbers and to predict trends. When outbreaks develop, several environmentally
safe chemical and microbial insecticides are effective in reducing larval
numbers and preventing serious defoliation. Computer models predicting growth
loss, tree mortality, and top-kill during outbreaks are available as aids to
making management decisions. Silvicultural practices favouring seral nonhost
species on high-risk sites may be the best prescription for reducing the effect
of tussock moth outbreaks.
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33. McDonald, P.M. and G.O. Fiddler.
1996. Development of a mixed shrub-tanoak-Douglas-fir community in a treated
and untreated condition. Pacific-Southwest-Research-Station,
USDA-Forest-Service Research-Paper PSW-RP-225. iv
+ 16 p.
Keywords: release treatments
manual release
chemical release
tree/stand health
growth
tree morphology
stand conditions
economics
Abstract: On a
medium site in northern California, a tanoak (Lithocarpus densiflorus)-mixed shrub
community in a Douglas fir plantation was given several treatments (manual
release two and three times, a combination chainsaw and cut surface herbicide
(Garlon 3A [triclopyr]) treatment, two foliar herbicides (2,4-D
or Garlon 4), and a tank mix of the two herbicides) to study its development in
both a natural (control) and treated condition. The herbicides were each
applied twice. Survival of planted Douglas fir (Pseudotsuga menziesii)
seedlings was recorded for 11 years and growth was quantified for 9 years after
the last treatment application. In addition to Douglas fir, data are presented
individually for the two most abundant species (tanoak and snowbrush, Ceanothus
velutinus var. hookeri), for greenleaf manzanita (Arctostaphylos patula), and
for the hardwood tree and shrubs combined. At the study's end in 1992, combined
vegetation in the control had a mean density of 1800 plants/acre, foliar cover of 23 700 ftsuperscript 2/acre, and height of 11.2 ft. In
contrast, combined tree and shrubs in the most effective treatment for
controlling them (cut and spray Garlon 3A) had a mean density of 150 plants/acre, foliar cover of 150 ftsuperscript 2/acre and
height of 5.9 ft at study end. Because competition for site resources
was low, Douglas fir seedlings developed best in this treatment. Mean Douglas
fir diameter was 4.6 inches at 12 inches above mean ground line, height
averaged more than 21 ft, and mean foliar cover was 39 850 ftsuperscript 2 at
the end of the study. The cost was $227 per acre.
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34. McDonald, P.M. and G.O. Fiddler.
1999. Ecology and development of Douglas-fir seedlings and associated plant
species in a Coast Range plantation. Pacific-Southwest-Research-Station,
USDA-Forest-Service Research-Paper PSW-RP-243. ii
+ 18 p.
Keywords: release treatments
manual release
chemical release
stand conditions
growth
tree morphology
economics
Abstract: On an
average site in northern coastal California, USA, a tanoak (Lithocarpus
densiflorus)-mixed shrub community was given several treatments (manual release
one, two, and three times; a combination chainsaw and cut surface chemical
treatment; two foliar chemicals; and a tank mix of the two chemicals) to study
its development over an 11-year period (1981-91) in both a broadcast-burned
(untreated control) and released (treated) condition. The chemicals were 2,4-D, Garlon [triclopyr] 3A, and Garlon 4, each applied two
times. The site had been planted with 2+0 seedlings of Douglas fir (Pseudotsuga
menziesii) in 1979. In addition to Douglas-fir , data
are presented individually for the four most abundant and well distributed
species (tanoak, hairy manzanita (Arctostaphylos columbiana), huckleberries
(Vaccinium ovatum and V. parviflorum), and rhododendron (Rhododendron
macrophyllum)), and for these plus two more of the tallest and most abundant
(but poorly distributed) species (snowbush (Ceanothus velutinus), elderberry
(Sambucus mexicana)) combined. In 1991, combined shrubs in the control had a
mean density of 4733 plants per acre, foliar cover of 16 800 ft2 per acre, and
height of 9.5 feet. In contrast, combined shrubs in one of the most effective
treatments for controlling them (2,4-D) had a mean density of 2000 plant per
acre, foliar cover of 2600 ft2 per acre and height of 5.5 feet at the end of
the study. Here, mean Douglas-fir diameter was 4.0 inches at 12 inches above
mean ground line, height averaged 18.7 feet, and mean foliar cover was 34 800
ft2 per acre. The cost (including chemical) was $77 per acre. The biological
and economical data in this paper provide the ecosystem manager, wildlife
biologist, and fuels manager with knowledge on how to attain plant communities
with different density and development potentials, and the cost of creating
them.
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35. McNabb, D.H., K. Baker-Katz and
S.D. Tesch. 1993. Machine site preparation improves seedling performance on a
high-elevation site in southwest Oregon. Western-Journal-of-Applied-Forestry 8(3): 95-98.
Keywords: site preparation
mechanical preparation
tree/stand health
stand conditions
growth
Abstract: Douglas
fir (Pseudotsuga menziesii) seedlings planted on areas receiving one of four
site preparation treatments (scarify, scarify/till, soil removal, and soil
removal/till) and on unprepared control areas were compared for 5 yr at a
high-altitude, nutrient-poor site in the western Siskiyou Mountains. Fifth-year survival of seedlings was at least 85% among
machine-prepared plots, compared to 42% on control plots. Cover of competing
vegetation remained less than 25% during the period for all machine treatments.
In contrast, vegetation cover on control plots was 30% at the time of planting
and increased to nearly 75% after 5 yr. Competing vegetation clearly impeded
seedling performance. The effects of unusually droughty conditions at the time
of planting in 1982 were examined further by interplanting additional seedlings
in the soil-removal treatment in 1985. The interplanting was followed by more
normal spring precipitation, and seedlings grew better over 5 yr than those
planted in 1982. The slow recovery of competing vegetation and generally poor
seedling growth on all treatments during both planting years are attributed to
low soil fertility.
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36. Messier, C. and A.K. Mitchell.
1994. Effects of thinning in a 43-year-old Douglas-fir stand on above- and
below-ground biomass allocation and leaf structure of understory Gaultheria
shallon. Forest-Ecology-and-Management 68(2/3): 263-271.
Keywords: thinning
stand conditions
Abstract: Salal
(Gaultheria shallon) was studied in an unthinned and a heavily thinned
(two-thirds of basal area removed) 43-yr-old Douglas fir (Pseudotsuga
menziesii) plot 6 yr after thinning at Shawnigan Lake on southern Vancouver
Island, British Columbia. The increase in both above- and below-ground
resources caused by thinning resulted in a smaller fine-root/leaf biomass ratio
in the thinned (1.2) than the unthinned (2.0) plot. The balance between the
production of fine-roots to acquire limited water and of foliage to acquire
limited light is suggested as an explanation for this shift in carbon allocation
from fine-root to leaf biomass between the two plots. The responses of G.
shallon to thinning are discussed in relation to its role as a competitor for
below-ground resources.
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37. Miller, J.C. and K.J. West. 1987.
Efficacy of Bacillus thuringiensis and diflubenzuron on Douglas-fir and oak for
gypsy moth control in Oregon. Journal-of-Arboriculture 13(10): 240-242.
Keywords: tree/stand protection
stand conditions
Abstract: In
studies at Corvallis, 20 trees of each of Quercus garryana and Douglas fir
[Pseudotsuga menziesii] were sprayed from the ground on 6 May 1986 until foliage dripped. Foliage was collected 1 day before
spraying and 1-64 days after spraying and bioassayed with 2nd instar larvae of
gypsy moth [Lymantria dispar]. Larval mortality was n.s.d. between tree species
or between insecticides. Both B. thuringiensis and diflubenzuron caused high
larval mortality and were effective for at least 64 days at the doses applied.
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38. 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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39. Moldenke, A.F., R.E. Berry, J.C.
Miller, R.G. Kelsey, J.G. Wernz and S. Venkateswaran. 1992. Carbaryl
susceptibility and detoxication enzymes in gypsy moth (Lepidoptera:
Lymantriidae): influence of host plant. Journal-of-Economic-Entomology 85(5):
1628-1635.
Keywords: tree/stand protection
stand conditions
Abstract: Toxicity
of carbaryl and levels of detoxifying enzymes were determined in larvae of
Lymantria dispar reared from hatching on either white alder (Alnus rhombifolia)
or Douglas fir (Pseudotsuga menziesii). Foliar chemistry was also examined.
Larvae were treated topically with carbaryl 2 days into the 3rd or 5th instar
and LD50s were established based on survival 48 h after treatment. Surviving
3rd-instar larvae were fed on their original diet until death or pupation and
sublethal effects were assessed. Levels of detoxifying enzymes were determined
in larvae of the same age and rearing group. Larvae reared on Douglas fir were
significantly more tolerant of carbaryl. Sublethal effects were found only in
larvae fed Douglas fir, in which mortality after 48 h and time to pupation were
significantly greater in treated larvae than in controls. Levels of
detoxification enzymes were generally higher in tissues of larvae raised on
Douglas fir, but significantly higher in only a few instances. Nitrogen and
phenolic contents were higher in alder than in Douglas fir. Terpenes were
abundant in Douglas fir foliage but were not detected in alder.
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40. Moldenke, A.F., R.E. Berry, J.C.
Miller and J.G. Wernz. 1997. Toxicity of acephate to larvae of gypsy moth as a
function of host plant and bioassay method.
Entomologia-Experimentalis-et-Applicata 84(2): 157-163.
Keywords: tree/stand protection
stand conditions
Abstract: The
toxicity of acephate to 3rd-instar larvae of Lymantria dispar was examined
under different conditions of administration method, availability of food to
larvae during bioassay, host plant, and activity of detoxifying enzymes. Larvae
that had been fed field-collected foliage of white alder (Alnus rhombifolia)
were less susceptible 48 h after treatment with topically applied acephate if
they were allowed to continue feeding on foliage during the bioassay period
(LD50 = 60.6 micro g/g larva) than if they were not (LD50 = 13.5 micro g/g
larva). All surviving larvae were replaced on their original food plant after
the 48-h bioassay; of these, 14.4% of the larvae not fed during treatment died
before pupation, compared with 1.3% of the larvae fed alder during treatment.
The LD50 obtained for topically treated larvae reared and treated on Douglas
fir (Pseudotsuga menziesii) (51.1 micro g/g larva) was
comparable to that obtained for larvae fed alder (60.0 micro g/g larva)
throughout treatment. Larvae treated orally with acephate, however, were
slightly more susceptible when reared on Douglas fir (LC50 = 20.3 ppm) than
when reared on alder (LC50 = 27.0 ppm). Post-treatment mortality in orally
treated larvae was 10.3% in those fed alder and 9.5% in those fed Douglas fir.
Higher cytochrome P-450 activities in larvae reared on Douglas fir apparently
did not enhance tolerance to acephate. Both sexes of orally treated larvae took
significantly longer to pupate than did controls on both foliage types, as did
topically treated males fed Douglas fir. Pupal weight generally was slightly,
but not always significantly, higher in treated than untreated larvae under all
dietary and treatment regimes.
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41. Moldenke, A.F., R.E. Berry, J.C.
Miller, J.G. Wernz and X.H. Li. 1994. Toxicity of Bacillus thuringiensis subsp.
kurstaki to gypsy moth, Lymantria dispar, fed with alder or Douglas-fir.
Journal-of-Invertebrate-Pathology 64(2): 143-145.
Keywords: tree/stand protection
stand conditions
Abstract: The
response of larvae of Lymantria dispar, reared on either Alnus rhombifolia or
Pseudotsuga menziesii following collection of egg masses from the field in Maryland in 1990, to treatment via an artificial diet with Bacillus
thuringiensis subsp. kurstaki (Javelin, 5% a.i.) was evaluated in the
laboratory. Mortality was independent of dose in both food plant treatments,
but was significantly greater for larvae fed the treated P. menziesii diet.
Sub-lethal effects and the role of food plant constituents with respect to
susceptibility to this biological control agent are also briefly discussed.
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42. Morrison, D. 1984. Evaluation of
impact - Advances in control. In Proceedings of the Sixth
International Conference on Root and Butt Rots of Forest Trees, International
Union of Forestry Research Organizations (IUFRO) Working Party S2.06.01.,
Melbourne, Australia, August 25-31, 1983. Ed. G.A. Kile. pp. 359-397.
Keywords: tree/stand protection
stand conditions
Abstract: Five
papers
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43. Murray, M.D. and R.E. Miller.
1986. Early survival and growth of planted Douglas-fir with red alder in four
mixed regimes. Pacific-Northwest-Research-Station,-USDA-Forest-Service Research-Paper PNW-RP-366. ii + 13 p.
Keywords: planting operations
release
treatments
growth
stand
conditions
Abstract: To
quantify interactions between species, the survival and growth of planted
Douglas fir in association with volunteer or planted red alder (Alnus rubra)
were studied at a site on the W. side of the Cascade Range, Washington. The
planted alders were wildings taken either from a nearby site or from a distant
coastal site and interplanted in a 3-yr-old Douglas fir plantation. The
volunteer alders established during the first year and were cut when the
plantation was 3 or 7 yr old. There was no apparent advantage in using
non-local alder to reduce aboveground competition with Douglas fir. Survival of
both sources of transplanted alder was high. Retaining about 1100 plants/ha of
volunteer alders until plantation age 7 yr had no measurable effect on Douglas
fir. It is recommended that, with alder densities of <1250/ha, alder control
on most land of average or below average site quality can be delayed until 6-8
yr after planting Douglas fir. This will reduce alder sprouting and allow
simultaneous control of alder and precommercial thinning of Douglas fir.
OSU
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44. Newton,
M. and E.C. Cole. 1989. Where does sulfometuron fit in Pacific
northwest
silviculture? Proceedings-of-the-Western-Society-of-Weed-Science (Vol. 42):
121-128.
Keywords: release
treatments
chemical release
stand conditions
tree/stand health
Abstract:
Field trials in the Oregon
Coast
Range
were conducted to evaluate sulfometuron for weed control in established and
newly-planted stands of Pseudotsuga menziesii. North
Coast
sites were aerially-sprayed with 0.11 or 0.22 kg/ha sulfometuron +or- 2.2 kg/ha
2,4-D. South Coast sites
received 0.11 or 0.165 kg/ha sulfometuron, and this was compared with 1.65
kg/ha hexazinone, 4.4 + 0.42 or 0.40 kg/ha atrazine + glyphosate +or- 1.25%
surfactant (R-11). Weed cover and tree damage were assessed visually. In South
Coast
sites, all treatments reduced weed cover >50%. Broadleaved weeds and grasses
were well controlled, but none of the treatments suppressed shrub growth.
Broadleaved weeds were best controlled by hexazinone,
and all other weeds by sulfometuron. On North
Coast
sites, all treatments reduced weed cover. Broadleaved weeds, grasses, shrubs
and Rubus ursinus were all suppressed, but ferns were not. 2,4-D enhanced the effect of sulfometuron on
broadleaved weeds and R. ursinus, but injury to P. menziesii was also greater.
This was acceptable on terminal growth <3-5 cm, above which foliage
necrosis, terminal dieback and growth check occurred. Timing of sulfometuron
treatment alone was not significant, and the effects of rate of application
were not clear from the first season's observations.
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45. Newton,
M., E.C. Cole and D.E. White. 1986. What influences control of coastal
deciduous brush with glyphosate.
Proceedings-of-the-Western-Society-of-Weed-Science (Vol.39): 86-92.
Keywords: release
treatments
chemical release
stand conditions
tree/stand health
Abstract:
The effects of 0.5, 1.0 or 1.5 lb a.e. glyphosate/acre as Rodeo or Roundup
applied in July or Aug. at 2 spray vol. with or without surfactant were studied
on 5 woody species in the Oregon
Coast
Range.
Glyphosate was more effective in 10 than 3 gallons spray/acre. Aug.
applications were best, except in the case of Alnus rubra and conifers which
were best controlled by July treatments. Addition of surfactant improved
efficiency at low rates and vol. of glyphosate. Rubus spectabilis was most
susceptible in Aug. and Sambucus racemosa was equally sensitive at both dates,
but R. procerus and R. laciniatus were resistant. In a 2nd trial against Acer
macrophyllum, crown reduction ranged from 60 to 85% with no differences between
rates but decreasing efficacy with lower spray volumes. Plantings of
Pseudotsuga menziesii were injured by all treatments in July but not in Aug.
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46. Oliver, C.D. and M.D. Murray. 1984. Stand structure, thinning
prescriptions, and density indexes in a Douglas-fir thinning study, Western
Washington, U.S.A.
Canadian-Journal-of-Forest-Research 13(1): 126-136.
Keywords: thinning
commercial thinning
growth
stand conditions
Abstract:
In a stand regenerated after logging in 1930, thinnings to set b.a. values were carried out in 1959, 1962, 1966, and 1970.
On each plot both large and small trees were removed since av. b.a. per tree was kept constant before and after thinning.
Volume growth varied greatly between plots of the same age, initial b.a., and site because of differences in stand structure.
Large trees on a plot grew more per tree and per b.a.
than small trees. Stand b.a., stand vol., number of
stems, or number of dominant and codominant trees were not closely related to
vol. growth/ha, although density indexes giving weight to larger trees showed
the closest relationship. The lack of a close relationship between stand
desnsity indexes and growth probably means the indexes do not uniquely define
structures; it does not necessarily mean that thinning will not increase volume
growth/ha. Volume growth/ha after thinning to a given b.a. will be greater and
probably more consistent if larger trees are left and enough time is allowed
for the stand to recover following thinning.
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47. Otvos, I.S., J.C. Cunningham and R.I. Alfaro. 1987. Aerial application
of nuclear polyhedrosis virus against Douglas-fir tussock moth, Orgyia
pseudotsugata (McDunnough) (Lepidoptera: Lymantriidae); II. Impact
1 and 2 years after application. Canadian-Entomologist 119(7-8):
707-715.
Keywords: tree/stand
protection
tree/stand
health
stand conditions
Abstract:
Following aerial application of a nuclear polyhedrosis virus of Orgyia
pseudotsugata against this lymantriid on Douglas fir (Pseudotsuga menziesii) in
British
Columbia in 1982, the impact
of treatment was studied in 1983 and 1984. The virus appeared to have spread
from treated plots to adjoining areas in 1982, effectively reducing lymantriid
populations. This observation suggests the spraying of alternate swaths to reduce
the amount of microbial pesticide used. A naturally occurring viral epizootic
reduced lymantriid populations in 2 of 3 check plots in 1983, but severe tree
mortality occurred in 2 of these plots, with 60 and 62% of sample trees dead in
1984. The corresponding tree mortality in 2 of 4 treated plots was 4 and 7%.
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48. Otvos, I.S. and R.F. Shepherd. 1991. Integration of early virus
treatment with a pheromone detection system to control Douglas-fir tussock
moth, Orgyia pseudotsugata (Lepidoptera: Lymantriidae), populations at
pre-outbreak levels. Forest-Ecology-and-Management 39(1-4): 143-151.
Keywords: tree/stand
protection
tree/stand health
stand conditions
Abstract:
The development and integration of a pheromone monitoring system with
a nuclear polyhedrosis virus treatment is described. Stands of Douglas fir
(Pseudotsuga menziesii) in British Columbia susceptible to tussock-moth
outbreaks are defined by overlying maps of past outbreaks, forest and habitat
types, and climatic zones. Pheromone-baited traps are placed and monitored
annually at permanent locations in susceptible areas. Measuring annual trends
of moth density indicates time and location of the next outbreak. Trap-catch
data provide an early warning of impending outbreaks, confirmed by ground
reconnaissance. Insect density and defoliation are predicted from egg-mass and
larval sampling. The virus can then be applied from the air or from the ground
into threatened stands to initiate an epizootic to prevent development of an
outbreak and to minimize tree damage. The virus appears to spread, and field
tests with reduced dosages indicate that the small amount of virus applied can
still greatly reduce larval populations and prevent tree mortality, at
considerably reduced cost.
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49. Overhulser, D.L., J.D. Walstad and R.P. Bowers. 1980. Twig weevil
damage to Douglas-fir seedlings and a field test of Dursban for control.
Tree-Planters' Notes 31(2): 17-20.
Keywords: tree/stand
protection
tree/stand health
stand conditions
Abstract:
Damage categories are described for young platations in Oregon
mostly 2+1 seedlings, planted in 1975-76 and surveyed in 1977 after attack by
Cylindrocopturus furnissi in 1976. A test using Dursban 4E (chlorpyrifos) spray
at 0-4% a.i., applied in July 1977, showed n.s.d. in % damaged trees between
treated and control areas after 4 months, but this may have been due to a
natural decline in weevil numbers. Spraying with 2% a.i. Dursban in Aug. 1977
significantly reduced the numbers of weevils present.
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50. 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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51. Reynolds, P.E., K. King, R. Whitehead and T.S. MacKay. 1986.
One-year results for a coastal British
Columbia glyphosate conifer release trial.
Proceedings-of-the-Western-Society-of-Weed-Science (Vol.39): 107-117.
Keywords: release
treatments
chemical release
stand conditions
growth
tree/stand health
Abstract:
In trials on the W. coast of Vancouver
Island in 1984, fir plantations on a reclaimed
watershed were aerially treated with 2 kg glyphosate/ha. A single spray gave
good control of Rubus spectabilis but very variable control of Alnus rubra
ranging from 0 to 100%. Gaultheria shallow [G. shallon] was not controlled by
glyphosate. Control of many species was greater on upper slopes than in the
watershed valley bottom. There was minor crop tree injury to Tsuga heterophylla
and Thuja plicata with recovery after 1 year, but no injury to Picea sitchensis,
Pseudotsuga menziesii, Abies amabilis or A. grandis. Some increases in crop
tree height were noted after herbicide treatment.
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52. Richmond,
R.M. 1983. Problems and opportunities of
forestland grazing in the Pacific Northwest.
In Forestland Grazing: Proceedings of a Symposium held February 23-25,
1983, Spokane, Washington.
Eds. B.F. Roche, Jr and D.M. Baumgartner, Pullman,
USA: Washington
State University.
pp. 71-73.
Keywords: release
treatments
stand conditions
tree/stand health
Abstract:
Grazing as a means of brush control in Douglas-fir plantations after
clearcut timber harvest was investigated in 1980-2 near Alsea,
Oregon.
Plots were restricted to clearcut areas with dominant vine maple [Acer
circinatum]/sword fern [Polystichum munitum] communities. In 1980-1 a flock of
600 ewes with lambs was used and in 1982 900 dry ewes were used. The sheep were
kept as a single flock and moved from clearcut to clearcut on a scheduled basis
from mid-May to late Aug. Approx. 6 acres were used per day. This management
reduced brush competition with Douglas fir seedlings,
did not significantly damage fir seedlings, stimulated regrowth of grazed
plants improving forage quality for big game and controlled Senecio jacobaea.
Av. daily weight gain of lactating ewes in 1981 was less than for the dry ewes
in 1982. Forage digestibility was adequate for dry ewes, but did not always
meet the requirements of the lactating ewes with lambs. These results are
discussed in the general context of forest management in the Pacific
Northwest.
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53. Riley, C.M., C.J. Wiesner, D.W. Scott, J. Weatherby and R.G.
Downer. 1992. Evaluating the field efficacy of Bacillus thuringiensis Berliner
against the western spruce budworm (Lepidoptera: Tortricidae). In Pesticide
formulations and application systems: 11th volume. Eds. L.E. Bode and
D.G. Chasin, ASTM, Philadelphia,
USA.
pp. 271-290.
Keywords: tree/stand
protection
stand
conditions
tree/stand health
Abstract:
A detailed assessment of spray deposition and efficacy of 2
formulations of Bacillus thuringiensis was carried out as part of a control
programme against Choristoneura occidentalis on Pseudotsuga menziesii and Abies
grandis in Oregon
in 1988. An analysis of covariance model that was used to examine the
relationship between deposit density and field efficacy (larval mortality and
defoliation) could not be justified, and the relationships between variables
were investigated using chi-squared analysis. This paper was presented at a
conference on pesticide formulations and application systems, held in San
Antonio, USA,
on 14-15 November 1991.
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54. 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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55. 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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56. Rose, R., J.S. Ketchum and D.E. Hanson. 1999. Three-year survival
and growth of Douglas-fir seedlings under various vegetation-free regimes.
Forest-Science 45(1): 117-126.
Keywords: release
treatments
chemical release
growth
tree morphology
tree/stand health
stand conditions
Abstract:
Responses of Douglas-fir (Pseudotsuga menziesii) seedlings were
studied for 3 yr (1993-96) following eight vegetation-control treatments in
three western Oregon
clearcuts. The objectives were to determine seedling growth response to
different areas of spot vegetation control and to determine the relative
influence of early woody and herbaceous competition on seedling growth.
Herbicide treatment areas varied in size from those receiving no control to
full control (9.3 msuperscript 2). Controlled areas were maintained free of
herbaceous vegetation for 2 yr and all woody vegetation was controlled for 3
yr. Two additional treatments, complete control of woody vegetation only and
complete control of herbaceous vegetation only, were also examined. On two
sites (Summit
and Marcola), seedling growth parameters were maximized at or near full
vegetation control with a tree spacing of 3 m x 3 m. On the third site (Pedee),
maximum growth response occurred between 5 and 6 msuperscript 2 of control.
Herbaceous vegetation control resulted in increased seedling growth at all
sites while woody vegetation control yielded increased seedling growth only at
the Pedee site. Cumulative 3 yr herbaceous cover accounted for 68% and 41% of
the variability in stem volume at Summit
and Marcola, respectively. Adding cumulative 3 yr woody cover to the model
accounted for an additional 18% and 49% of the variability in stem volume at Summit
and Marcola, respectively. At Pedee, neither herbaceous nor woody cover
significantly influenced 3 yr stem volume, suggesting that factors other than
vegetation cover were responsible for differences measured.
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57. Ross, D.W., K.E. Gibson, R.W. Thier and A.S. Munson. 1996. Optimal
dose of an antiaggregation pheromone (3-methylcyclohex-2-en-1-one) for
protecting live Douglas-fir from attack by Dendroctonus pseudotsugae
(Coleoptera: Scolytidae). Journal-of-Economic-Entomology 89(5): 1204-1207.
Keywords: tree/stand
protection
tree/stand health
stand conditions
Abstract:
The Dendroctonus pseudotsugae antiaggregation pheromone,
3-methylcyclohex-2-en-1-one (MCH), was applied to stands of Douglas fir,
Pseudotsuga menziesii in Oregon,
Montana,
Idaho
and Utah,
at high risk for infestation to determine the lowest effective dose for protecting
live trees. MCH was applied at rates of 50, 100, and 150 bubble capsules per
hectare (20, 40, and 60 g/ha, resp.) in 1994, and 15, 30, and 50 bubble
capsules per hectare (6, 12, and 20 g/ha, resp.) in 1995. Mean release rates
throughout the beetle flight periods in 1994 and 1995 were 1.63 and 1.23
milligrams per capsule per day, resp. For both years, catches of Douglas fir
beetles in pheromone-baited traps located at the plot centers were
significantly lower on all MCH-treated plots compared with untreated plots, but
there were no differences among the 3 doses of MCH. In contrast, MCH had no
effect on the numbers of 3 predators (Thanasimus undatulus, Enoclerus sphegeus
and Temnochila chlorodia [Temnoscheila chlorodia]) collected in the traps
during either year. In 1994, the percentage of Douglas fir <more or =>20
cm diameter at breast height (dbh) that were mass attacked was significantly
lower on MCH-treated plots compared with the untreated control, and all 3 doses
were equally effective. In 1995, there were no significant differences in the
percentage of mass-attacked trees among the treatments. These results
demonstrate that MCH applied at rates as low as 20 g/ha (50 bubble capsules per
hectare) can reduce the probability that high-risk Douglas fir will become
infested.
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58. Sandquist, R.E., D.L. Overhulser and J.D. Stein. 1993. Aerial
applications of esfenvalerate to suppress Contarinia oregonensis (Diptera:
Cecidomyiidae) and Megastigmus spermotrophus (Hymenoptera: Torymidae) in
Douglas-fir seed orchards. Journal-of-Economic-Entomology 86(2): 470-474.
Keywords: seed
orchard management
tree/stand protection
stand conditions
Abstract:
Aerial application of esfenvalerate significantly reduced populations
of Contarinia oregonensis and Megastigmus spermotrophus in mature seed orchards
of Pseudotsuga menziesii in Oregon.
Populations of Oligonychus ununguis increased significantly in treated areas.
The results demonstrated that aerial applications can be made under conditions
in the Pacific Northwest and can
reduce insect damage levels with between 10 to 20-times less insecticide than when high-volume orchard sprayers
are used.
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59. Schneider, W.G., S.A. Knowe and T.B. Harrington. 1998. Predicting
survival of planted Douglas-fir and ponderosa pine seedlings on dry,
low-elevation sites in southwestern Oregon.
New-Forests 15(2): 139-159.
Keywords: site
preparation
mechanical preparation
prescribed fire
tree/stand health
tree morphology
stand conditions
Abstract:
Four equations were developed by logistic regression for predicting
the probability of Douglas fir (Pseudotsuga menziesii) and ponderosa pine
(Pinus ponderosa) survival for the first (0-1) and first to third (1-3) growing
seasons after applying mulching, radial scalping (removal of all vegetation and
a thin layer of soil in a 1-m radius area around each tree), or artificial
shading (shade cards) treatments in plantations in SW Oregon. Most of the sites
had been burned by wildfire or prescribed fire before planting. Variables
describing conifer size, levels of competing vegetation, presence of
silvicultural treatments, site factors, and climate factors were collected from
13 sites up to 6 yr after planting and examined as potential predictors of
survival. Age, stem diameter, a competition index for shrubs, severity of
growing season at time of treatment, average annual precipitation, aspect, and
slope angle were predictors of Douglas fir survival during 0-1 and 1-3 growing
seasons after treatment; the presence of silvicultural treatments was also a
predictor only during the first growing season after treatment. Age, aspect,
and slope angle were predictors of ponderosa pine survival over both 0-1 and
1-3 growing seasons after treatment; height-diameter ratio, competition indices
for herbs, shrubs, and hardwoods, silvicultural treatment, severity of growing
season at time of treatment, and average annual precipitation were also
predictors only during the first growing season after treatment; crown width
was a predictor of survival only during 1-3 growing seasons after treatment.
When significant in the models (equations), predicted probability of survival
increases with treatments, less severe weather conditions, diameter, crown
width, age, and precipitation; probability decreases with increasing
height-diameter ratio and competition indices for herbs, shrubs, and hardwoods.
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60. Sharrow, S.H., W.C. Leininger and K.A. Osman. 1992b. Sheep grazing
effects on coastal Douglas fir forest growth: a ten-year perspective.
Forest-Ecology-and-Management 50(1-2): 75-84.
Keywords: release
treatments
tree/stand
health
stand conditions
growth
Abstract:
In a study evaluating effects of controlled sheep grazing on Douglas
fir (Pseudotsuga menziesii) growth, tree diameter and height growth were
measured during 1981-1990 in ungrazed and grazed tree stands in the Siuslaw
National Forest, Oregon. Grazed stands were intensively used by a herded flock
of 700-900 sheep for 3-4 days each May and August 1981 and 1982. The stand had
been clear felled in 1977, burned in 1978, and planted with 3-year-old trees in
1980. Orchardgrass (Dactylis glomerata) was also sown aerially in 1980 to
provide a food source for large indigenous herbivores and help slow the
establishment of unwanted woody vegetation. Understorey vegetation phytomass
and its utilization by sheep was
evaluated using a before-and-after technique in 1981 and 1982. Sheep removed
28% and 64% of new tree lateral branches in 1981 and 1982, respectively. The
major effect of browsing, however, appeared to be removal of terminal leaders
which reduced 1990 Douglas fir tree height by 61 cm and diameter at breast
height (d.b.h.) by 1.9 cm for each terminal removed. Sheep browsed terminal
leaders of 38% and 77% of grazed plantation trees in 1981 and 1982,
respectively. Grazing proved very effective in reducing red alder (Alnus rubra)
establishment and growth. Total tree basal area in 1990 was similar for grazed
and ungrazed stands. However, red alder trees contributed over 45% of tree
basal area on ungrazed stands compared with 19% on grazed stands. Vegetation
control by sheep, without associated browsing of terminal leaders, increased
1990 Douglas fir height by 16% and d.b.h. by 34%. Net effect of grazing (taking
into account the negative effects of browsing together with the positive
effects of reduced competing vegetation) was to increase 1990 Douglas fir
height by 6% and d.b.h. by 22% on grazed compared with ungrazed timber stands.
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61. Sharrow, S.H., W.C. Leininger and B. Rhodes. 1989. Sheep grazing
as a silviculture tool to suppress brush. Journal-of-Range-Management 42(1):
2-4.
Keywords: release
treatments
stand conditions
growth
Abstract:
Three 4- to 6-year-old Douglas fir (Pseudotsuga menziesii) plantations
were grazed by sheep once each year during the May to Sep. grazing season in 1981-82.
Estimates of current year's growth present in Oct. both inside and outside a
livestock exclosure on each plantation, were used to evaluate the effects of
grazing on the growth of Acer circinatum and Rubus spp. In general, utilization
of brush by sheep was moderate to heavy, except in the spring of 1982, when
brush was lightly utilized. Sheep grazing effectively reduced both total
understorey plant growth and brush net current year's growth on all
plantations. Reduced brush biomass on grazed areas was associated with greater
Douglas fir diam. growth in 1981-82 and 1982-83. By 1985, trees in grazed areas
were 5% higher and 7% greater in diam. than trees on ungrazed controls.
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62. Shepherd, R.F. 1994. Management
strategies for forest insect defoliators in British Columbia. Forest-Ecology-and-Management
68(2/3): 303-324.
Keywords: tree/stand
protection
growth
tree/stand health
stand conditions
Abstract:
A synthesis is presented of outbreak characteristics of common
defoliating insects in forests (mainly Pseudotsuga menziesii) in British
Columbia. Two types of
outbreak are identified: fast-cycling and sustained outbreaks. Species with
fast-cycling outbreaks rise quickly to visible defoliation levels, cause
significant growth loss, tree deformation and mortality, and disappear just as
quickly. Fast-cycle species noted include the Douglas fir tussock moth (Orgyia
pseudotsugata), western blackheaded budworm (Acleris gloverana), black army
cutworm (Actebia fennica [Ochropleura fennica]), western hemlock looper
(Lambdina fiscellaria lugubrosa), false hemlock looper (Nepytia freemani),
greenstriped forest looper (Melanolophia imitata), and the saddleback looper
(Ectropis crepuscularia). The effect of such outbreaks is closely related to
the severity of defoliation during the first year; consequently, the objective
of managing these species should be to reduce populations before defoliation
occurs, i.e. to prevent the outbreak. To accomplish this objective,
identification of susceptible habitats and monitoring with sensitive pheromone
traps in areas of expected outbreaks are necessary to detect upwelling populations.
Species with sustained outbreaks (typified by the various species of spruce
budworms (Choristoneura spp.), e.g., the western spruce budworm, C.
occidentalis, the 2-year cycle budworm, C. biennis, and C. orae) cause
significant growth losses only after defoliation continues for a number of
years. Tree mortality usually is not important except where regeneration is
being nurtured under a selective or shelterwood silvicultural system. Impact
can be significant over the life of a stand because of the length and frequency
of outbreaks, but treatments effective for only 1 year usually cannot be
justified except where it is important to retain a full crown. Long-term
cultural methods appear to be the preferred management system and, of these,
utilizing non-host species or resistant or phenologically asynchronous host
species may be the best option. Again, determining the location of expected
outbreaks is an important component of a management system and, at present,
identifying stands by frequency of outbreak within zones of climatic
suitability would be useful in selecting treatment areas.
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63. Shepherd, R.F., T.G. Gray, R.J. Chorney and G.E. Daterman. 1985. Pest
management of Douglas-fir tussock moth, Orgyia pseudotsugata (Lepidoptera:
Lymantriidae): monitoring endemic populations with pheromone traps to detect
incipient outbreaks. Canadian-Entomologist 117(7): 839-848.
Keywords: tree/stand
protection
tree/stand health
stand conditions
Abstract:
The numbers of adults of Orgyia pseudotsugata caught in sticky
delta-shaped pheromone traps baited with different concentrations of synthetic
lures were compared with egg-mass densities and subsequent tree defoliation
throughout a population cycle in British
Columbia. A lure containing
0.01% pheromone by weight in the form of a 3 x 5-mm poly(vinyl chloride) rod provided more consistent
catches than pheromone concentrations of 0.0001, 0.001, 0.1 or 1.0%. Trap
saturation occurred when over 40 moths per trap were caught. To achieve a
standard error of 30%, 6 traps were required at each site. There was a poor
correlation between numbers of moths
caught and egg-mass density or defoliation estimates in the following
generation, but a threshold density was found that provides a warning of an
incipient outbreak. Ground surveys for egg-masses are recommended to confirm
suspected infestations after continuous increases in moth catches for 2-3 years
or if an average of 25 moths or more per trap has been caught.
OSU
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64. Shepherd, R.F., I.S. Otvos and R.J. Chorney. 1984a. Pest
management of Douglas-fir tussock moth (Lepidoptera: Lymantriidae): a
sequential sampling method to determine egg mass density. Canadian-Entomologist
116(7): 1041-1049.
Keywords: tree/stand
protection
tree/stand health
stand conditions
Abstract:
A sequential egg-mass sample system for Orgyia pseudotsugata (McDunn.)
was designed, based on visual
scanning of the lower branches of Douglas firs (Pseudotsuga
menziesii) in British Columbia. A
branch was removed from each quadrant from the upper, middle and lower crown
level, and from the lowest whorl of a total of 59 non-defoliated trees in 10
areas. No consistent trend in egg-mass density per branch could be found
between crown levels, so the lower whorl of branches was selected for survey
purposes. Sample stop lines were determined from egg-mass density and
variability data collected on 55 sites, and subsequent defoliation estimates
were related to these densities. The system is designed as an early detection
tool to be used only in non-defoliated stands at the incipient stage of an
impending outbreak.
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65. Shepherd, R.F., I.S. Otvos, R.J. Chorney and J.C. Cunningham.
1984b. Pest management of Douglas-fir tussock
moth (Lepidoptera: Lymantriidae): prevention of an outbreak through early
treatment with a nuclear polyhedrosis virus by ground and aerial applications.
Canadian-Entomologist 116(11): 1533-1542.
Keywords: tree/stand
protection
tree/stand health
stand conditions
Abstract:
Two application methods were tested using a nuclear polyhedrosis virus as a
biological control agent at an early stage in an outbreak of Orgyia
pseudotsugata on Douglas fir [Pseudotsuga menziesii] in British
Columbia in 1981. The virus,
which often leads to the development of an epizootic late in the outbreak
cycle, was propagated in O. leucostigma. Four plots were treated from a
helicopter at a dosage of 2.2 x 1011 polyhedral inclusion bodies (PIB) in an
emitted spray volume of 11.3 litres/ha; 5-8 weeks after spraying, 77-100% of
live larvae were infected. Two plots were treated from the ground at 2.4 x 1010
PIB in 4.5 litres/tree; 8
weeks after treatment 83-85% of live larvae were infected. No egg-masses could
be found in the treated plots in the autumn of 1981, and no larvae were found
on sample trees in 1982 or 1983. The treatment was effective over a range of
initial mean larval densities of 41-206/msuperscript 2 foliage. Populations in
untreated areas nearby increased in 1982. Little foliage protection was
obtained the year of application, due to the lengthy virus incubation period,
but the trees recovered quickly when larval populations disappeared.
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66. Smith,
N.J.
1991. Sun and shade leaves: clues to how salal (Gaultheria shallon) responds to
overstory stand density. Canadian-Journal-of-Forest-Research 21(3): 300-305.
Keywords: release
treatments
stand conditions
Abstract:
The results are presented of an examination of leaf biomass, leaf area
index, specific leaf area and leaf morphology of Gaultheria shallon from 37
destructively measured 1 msuperscript 2 quadrats in 13 Douglas fir (Pseudotsuga
menziesii) second-growth stands on Vancouver
Island, British Columbia.
In response to light and stand overstorey density, salal shoots produced either
mainly sun leaves or mainly shade leaves. Sun leaves were associated with
sunflecks in open-grown or variably stocked stands. Shade leaves were
associated with diffuse light under denser stands. Sun-leaf quadrats had mean specific
leaf areas <90 cmsuperscript 2/g; shade-leaf quadrats had mean specific leaf
areas >90 cmsuperscript 2/g. Sun leaves were narrower, with average leaf
widths <5 cm. Quadrat salal leaf biomass and leaf area index peaked at
Curtis' metric relative density 5.9, which corresponded to an availability of
15% of global photosynthetically active radiation. Sun-leaf quadrats occurred
below relative density 5; shade-leaf quadrats occurred above relative density
4. A mixture of sun- and shade-leaf quadrats occurred between about relative
density 4 and 5, depending on the uniformity of stocking. Application of these
observations for salal control (to reduce competition), or to increase salal
browse production, are discussed.
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67. Stapanian, M.A. and D.W. Shea. 1986. Lignosulfonates: effects on
plant growth and survival and migration through the soil profile.
International-Journal-of-Environmental-Studies 27(2): 45-56.
Keywords: release
treatments
chemical release
growth
stand conditions
Abstract:
The effects of a refined lignosulfonate product obtained from the sulfite
pulping process, on growth and survival of plants were investigated. After
applications of 0, 7500, 15 000 and 22 500 cmsuperscript 3/msuperscript 2 to
plots within a forest plantation, the following were monitored: (1) live
aboveground biomass of vascular plants, (2) growth of Douglas fir (Pseudotsuga
menziesii) and (3) lignosulfonate migration through the soil profile. Biomass
of woody vegetation was not affected, and that of herbaceous plants was
significantly decreased only at the two greatest application rates. Growth of
the Douglas fir trees was not significantly affected. Lignosulfonates
disappeared from the soil profile at the same rate regardless of initial
concentration. Although it is not practical to use this material as a herbicide in western Washington,
land application of lignosulfonates may be environmentally more attractive than
traditional disposal methods.
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68. Stein, J.D. and G.P. Markin. 1986. Evaluation of four chemical
insecticides registered for control of the Douglas-fir cone gall midge,
Contarinia oregonensis (Diptera: Cecidomyiidae), and the Douglas-fir seed
chalcid, Megastigmus spermotrophus (Hymenoptera: Torymidae), in Douglas-fir
seed orchards. Canadian-Entomologist 118(11): 1185-1191.
Keywords: seed
orchard management
tree/stand protection
stand conditions
tree/stand health
Abstract:
The control of Contarinia oregonensis and Megastigmus spermotrophus on
Douglas fir (Pseudotsuga menziesii) in Washington
and Oregon
in 1982 and 1983 depended on the levels of infestation and which of 4
insecticides was used. There was no significant reduction in infestation of
either pest when acephate was applied. Oxydemeton-methyl (by spray or
injection) and dimethoate (in sprays) significantly reduced damage by C.
oregonensis. These three compounds and azinphos-methyl were ineffective against
M. spermotrophus for infestations affecting <10% of extractable seed.
Oxydemeton-methyl injections, azinphos-methyl and dimethoate significantly
reduced the incidence of the chalcid when infestation was high (61%). There was
no statistically significant difference for pairwise comparisons between
compounds that significantly reduced infestation with either pest.
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69. Stein, J.D., R.E. Sandquist, T.W. Koerber and C.L. Frank. 1993.
Response of Douglas-fir cone and seed insects to implants of systemic
insecticides in a northern California
forest and a southern Oregon
seed orchard. Journal-of-Economic-Entomology 86(2): 465-469.
Keywords: seed
orchard management
tree/stand protection
tree/stand health
reproduction
stand conditions
Abstract:
The systemic insecticides acephate, dimethoate and carbofuran were
implanted into Pseudotsuga menziesii at Oakridge,
Oregon
and Willow Creek,
California,
to evaluate their effectiveness in reducing seed and cone insect damage. The
acephate-implant treatment significantly reduced seed damage by Barbara
colfaxiana and Contarinia oregonensis, and significantly increased the
percentage of filled seed by 300% at the California
site. Neither dimethoate nor carbofuran significantly affected any of the seed
or cone insects encountered. Acephate was not effective against Megastigmus
spermotrophus or Leptoglossus occidentalis. The association observed between C.
oregonesis damage and undeveloped seeds suggested that management strategies
that include effective control measures should also include methods to monitor
and reduce seed abortion.
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70. Stein, W.I. 1997. Ten-year
survival and growth of planted Douglas-fir and western redcedar after seven site-preparation
treatments. Western-Journal-of-Applied-Forestry 12(3): 74-80.
Keywords: site
preparation
chemical preparation
prescribed fire
tree/stand protection
growth
tree/stand health
stand conditions
Abstract:
Western redcedar (Thuja plicata) and Douglas fir (Pseudotsuga
menziesii) were planted together after applying seven site-preparation methods
at one cable-logged site in the Oregon Coast Ranges. The treatments, applied
during 1980, were: untreated control; spot clear by cutting; aerial spraying
with glyphosate; broadcast burning; slash and burn; spray with Tordon 101
(picloram + 2,4-D) and burn; and burn and sow grass. Planting was done in early
1991, and vegetation and trees were measured periodically to 1990. Survival and
growth of cedar were markedly less than Douglas fir on this favourable site
where both species were components of the original stand. Repeated browsing
severely impeded the cedar. Site preparation by broadcast burning generally
yielded the best results, but sowing grass after broadcast burning produced
Douglas fir responses similar to those for no site preparation. Where grass was
sown, herbaceous cover was more abundant and taller, salmonberry (Rubus
spectabilis) differed little in density but was slightly taller, and
development of red alder (Alnus rubra) was delayed. Red alder is currently
overtopping conifers in all treatments, and release is needed to ensure
sufficient conifer survival.
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71. Stelzer, M.J. and R.C. Beckwith. 1988. Comparison of two isolates
of Bacillus thuringiensis in a field test on western spruce budworm
(Lepidoptera: Tortricidae). Journal-of-Economic-Entomology 81(3): 880-886.
Keywords: tree/stand
protection
stand conditions
tree/stand health
Abstract:
Two isolates of Bacillus thuringiensis (Thuricide 32LV [B.
thuringiensis subsp. thuringiensis] and SAN-415 32LV) were compared for
efficacy against Choristoneura occidentalis on Douglas fir (Pseudotsuga
menziesii) and grand fir (Abies grandis) in Oregon.
The insecticides were applied aerially at 20 and 30 billion International Units
in a spray volume of 7.1 litres/ha. The 30 BIU/ha dosage provided better
population control than 20 BIU/ha dosage with both formulations; however, only
the difference between dosages for the SAN-415 32LV formulation was significant.
Differences in efficacy between the isolates were not significant. The
application of B. thuringiensis improved foliage protection by 15-25% compared
with untreated plots.
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72. Summers, D. and G.E. Miller. 1986. Experience with systemic
insecticides for control of cone and seed insects in Douglas-fir seed orchards
in coastal British
Columbia, Canada.
In Proceedings of the 2nd Conference of the Cone and Seed Insects
Working Party, Station de Zoologie Forestiere, Olivet, France, September 3-5,
1986. Ed. A. Roques. pp. 267-283.
Keywords: seed
orchard management
tree/stand protection
tree/stand health
reproduction
stand conditions
Abstract:
Three systemic insecticides were screened experimentally, and 2 of
them used operationally, against cone and seed insects (especially Contarinia oregonensis,
Megastigmus spermotrophus and Barbara colfaxiana), in seed orchards of Douglas
fir [Pseudotsuga menziesii] on Vancouver
I., British
Columbia. Dimethoate, as a
foliar spray, controlled the pests and increased the number of filled seeds per
cone, making it the recommended choice. Oxydemeton-methyl, as a foliar spray,
was as effective as dimethoate in controlling the insects but appeared less
effective in increasing the number of filled seeds. Injections of
oxydemeton-methyl were less effective than foliar sprays in controlling insect
damage. Acephate as a foliar spray was inconsistent in the level of pest
control achieved and as an injection gave poor results; its use was also
associated with the development of serious outbreaks of Adelges cooleyi
[Gilletteella cooleyi].
Non-OSU
Link
73. Summers, D. and D.S. Ruth. 1987. Effect of diatomaceous earth, malathion, dimethoate and
permethrin on Leptoglossus occidentalis (Hemiptera: Coreidae): a pest of
conifer seed. Journal-of-the-Entomological-Society-of-British-Columbia 84:
33-38.
Keywords: tree/stand
protection
stand conditions
Abstract:
Field and laboratory studies were carried out in British
Columbia in 1986 to test the
efficacy of some insecticides against Leptoglossus occidentalis attacking
Douglas fir (Pseudotsuga menziesii). The coreids were exposed to diatomaceous
earth [diatomite], and sprays of 0.1 and 1.0% Lagon 2E (dimethoate) and 0.1 and
0.01% Ambush 50 EC (permethrin) in both laboratory and field tests and to 0.1% malathion in the laboratory. In
field tests, permethrin and dimethoate caused significant mortality for 2 weeks
after sprays were applied and permethrin continued to be effective for a 3rd
week. Diatomite was not effective in the field tests or in 1 of 2 laboratory
tests. Malathion, dimethoate and permethrin caused significant mortality in
both laboratory tests.
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74. Trotter, D.B. and G.M. Shrimpton. 1989. Oxyfluorfen (Goal) trials
with bareroot forest seedlings in British
Columbia 1987. B.C.
Ministry of Forestry FRDA Report 092. vi + 22 p.
Keywords: nursery
operations
tree/stand health
stand conditions
Abstract:
Oxyfluorfen was evaluated at various rates for weed control and crop
tolerance on 1+0 and 2+0 bare rooted seedlings of Douglas fir (Pseudotsuga
menziesii) and lodgepole pine (Pinus contorta) at Surrey Nursery, British
Columbia.
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75. Vihnanek, R.E. and T.M. Ballard. 1988. Slashburning effects on
stocking, growth, and nutrition of young Douglas-fir plantations in
salal-dominated ecosystems of eastern Vancouver
Island. Canadian-Journal-of-Forest-Research 18(6):
718-722.
Keywords: site
preparation
prescribed fire
growth
tree physiology
stand conditions
Abstract:
Stocking, ht. growth, basal diam. growth, and foliar nutrient concn. of 5- to 15-yr-old Douglas fir
(Pseudotsuga menziesii) were evaluated on burned and unburned areas within each
of 20 sites on eastern Vancouver Island,
which were characterized by ecosystems dominated by salal (Gaultheria shallon).
Burning significantly reduced salal ht. and cover and significantly increased
Douglas fir stocking, ht. growth, basal diam. and foliar P, K, Ca, Fe, and B
concn. Foliar concn. of N, Mg, S, Zn and Cu were not
significantly affected. Foliar Mn concn.
were significantly reduced
but remained very far above the deficiency threshold.
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76. Wagner, R.G. and S.R. Radosevich. 1991b. Neighborhood predictors of interspecific competition in
young Douglas-fir plantations.
Canadian-Journal-of-Forest-Research 21(6): 821-828.
Keywords: site
preparation
stand conditions
growth
Abstract:
Neighbourhood models describing the effect of interspecific competition
on the height and stem diameter of 4- to 9-year-old saplings of Douglas fir
(Pseudotsuga menziesii) were developed from site preparation experiments in the
Oregon
Coast Range.
Existing study records and maps were used to randomly select 787 saplings from
78 study plots at nine sites. The influence of abundance measures, height,
distance, and spatial arrangement of nonconiferous woody plants surrounding
individual saplings was examined. Optimum neighbourhood heights and radii were
defined. The best interspecific competition index for predicting Douglas fir
height and stem diameter was total percentage cover for all woody species
within a 2.1-m radius. Visual estimates of neighbour cover were superior to
objective measures of crown area. The cover of woody species equalling or
exceeding the height of the tree provided the best prediction for tree height.
Woody species cover equalling or exceeding one-half the height of the tree
provided the best index for predicting stem diameter. Accounting for the
spatial arrangement of neighbouring woody plants did not improve the
competition index. Interaction between the competition index and tree age
indicated that the negative effect of interspecific competition on Douglas fir
size increased with time. The age-adjusted competition index accounted for 11%
of the variation in height and 19% of the variation in stem diameter. Douglas
fir stem diameter was more sensitive to neighbouring woody plants than was
height.
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77. Wagner, R.G. and M.W. Rogozynski. 1994. Controlling sprout clumps
of bigleaf maple with herbicides and manual cutting. Western Journal of Applied
Forestry 9(4):118-124.
Keywords: release
treatments
chemical release
manual release
stand conditions
Abstract:
Trials were conducted in 5 young Douglas fir (Pseudotsuga menziesii)
plantations for controlling bigleaf maple (Acer macrophyllum) clumps.
Herbicides tested were glyphosate (Roundup), imazapyr (Arsenal), metsulfuron
methyl (Escort), triclopyr amine (Garlon 3A), triclopyr ester (Garlon 4), and 2,4-DP [dichlorprop] + 2,4-D
(Weedone 170). Four methods of herbicide application (basal spray, thinline,
foliage spray, and cut-surface) and 3 treatment timings (early foliar, late
foliar, and dormant periods) were tested. Manual cutting alone was also
evaluated at each of the treatment timings. Imazapyr foliage sprays, triclopyr
ester thinline, dormant 3% triclopyr ester basal spray, late-foliar 2,4-DP +
2,4-D basal spray, and manual cutting with triclopyr amine cut-surface
application provided the best control among the treatments tested over the 3 yr
of study. Imazapyr foliage sprays provided the best long-term control by
killing most treated clumps. Triclopyr ester thinline treatments provided the
most consistent and effective results among the basal applications. Stump
applications of triclopyr amine were more effective than manual cutting alone
or manual cutting with glyphosate cut-surface application.
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78. Wass, E.F. and R.B. Smith. 1997. Impacts of stump uprooting on a
gravelly sandy loam soil and planted Douglas-fir seedlings in south-coastal British
Columbia. Pacific-Forestry-Centre,-Canadian-Forest-Service Information-Report BC-X-368.
vi + 15 p.
Keywords: site
preparation
mechanical preparation
tree/stand protection
soil properties
stand conditions
growth
Abstract:
Studies to determine levels and impacts of soil disturbance caused during
root-disease control by stump removal were initiated on a cutover on southern Vancouver
Island immediately prior to the control operation and
the establishment of a plantation of Douglas-fir (Pseudotsuga menziesii). Soil
surface condition was assessed on the stumped area. Soil disturbance was
measured at 699 planting spots. Vegetation development was assessed at 10% of
the spots. Of all planting spots, 180 were undisturbed soil, 277 deposits and
242 gouges. The soil, a gravelly sandy loam, increased naturally in soil
density with depth from 1.05 t/msuperscript
3 at the surface to over 1.60 t/msuperscript 3 at depths more
than 40 cm. Disturbance did not significantly increase soil density. Unlike
previous studies of this nature, ease of soil penetrability was increased by
the stump uprooting disturbance and vegetation development was not greatly dissimilar
between disturbed and undisturbed soil. The relatively low soil impacts were
attributed to the ability of the excavator to pile stumps without pushing
topsoil, and the low site sensitivity to compaction. These low impacts on soil
and reduced vegetative competition on disturbed soil resulted in tree growth
rates which were significantly greater after 10 years on deposits (12% in
height and 18% in diameter) and gouges (6% in height and 8% in diameter) than
on undisturbed soil.
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79. White, D.E. and M. Newton. 1983. Effects of glyphosate and two
formulation of hexazinone in young conifer plantations.
Proceedings-of-the-Western-Society-of-Weed-Science (Vol.36): 54-56.
Keywords: release
treatments
chemical release
growth
stand conditions
tree/stand health
Abstract:
In April 1979, 1 month after transplanting 3-yr-old Douglas fir (Pseudotsuga
menziesii), hexazinone liquid and solid formulations at 0, 1.11, 1.68 or 2.23
kg/ha were applied to the plots separately and in combination with 0 or 0.62 kg
glyphosate/ha. There was no significant difference between formulations of
hexazinone in effect on the herbaceous community which was dominated by
Arrhenatherum elatius, Holcus lanatus, Elymus glaucus and Rubus ursinus.
However, addition of glyphosate increased the mean weed-free condition from
67.25 to 85.1%. At the same time, in glyphosate-treated plots, mean ht. of 4th
yr trees was 149.9 cm compared with 162.6 cm in hexazinone-only plots. Survival
of 2nd yr trees was also affected.
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80. White, D.E. and M. Newton. 1989. Competitive interactions of
whiteleaf manzanita, herbs, Douglas-fir, and ponderosa pine in southwest Oregon.
Canadian-Journal-of-Forest-Research 19(2): 232-238.
Keywords: release
treatments
chemical release
growth
stand conditions
Abstract:
Whiteleaf manzanita (Arctostaphylos viscida) was established on 3
sites in Oregon
in 1983 at densities ranging from 0 to 27 000 seedlings/ha in 2-yr-old mixed
Douglas fir (Pseudotsuga menziesii)/ponderosa pine (Pinus ponderosa) stands.
Invading herbs were controlled by spraying all plots with glyphosate and
hexazinone, except one at each site at the 13 500 density. Intraspecific
manzanita competition reduced individual shrub basal diameter, leaf area,
biomass, and canopy volume by the 3rd year of the study. Stem volume of
5-yr-old conifers was reduced in relation to manzanita density, biomass, LAI,
and canopy cover. The presence of herbaceous vegetation reduced both manzanita
and conifer growth by the 3rd year.
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81. 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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82. 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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