1. 1987. Impact of intensive forestry practices on net stand
values in British
Columbia. B.C. Ministry of Forests FRDA-Report 014. 109
p.
Keywords: release treatments
fertilization
thinning
yield
economics
Abstract: Yield responses to major silvicultural treatments
(regeneration method, brushing and weeding, spacing and thinning and fertilizer
use) are analysed in relation to growth and yield theory, and their translation
into operational use of treatments to increase merchantable vol. is considered.
Data from coastal Douglas fir (Pseudotsuga menziesii), western hemlock (Tsuga
heterophylla) and western hemlock/Abies amabilis stands and interior white
spruce (Picea glauca), lodgepole pine (Pinus contorta) and wet belt Douglas fir
stands are used to quantify the net present value of treatments in terms of
improvement in net stand values and merchantable vol. Potentially viable
treatment options are identified for each stand type present.
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2. Belz, D. and T.E. Nishimura. 1989.
Effects of imazapyr, 2,4-D and metsulfuron methyl on
conifer tolerance. Proceedings-of-the-Western-Society-of-Weed-Science (Vol.
42): 98-104.
Keywords: site preparation
chemical preparation
release treatments
chemical release
tree/stand health
Abstract: Imazapyr
at 0.25-1.0 lb/acre alone or 0.5 lb/acre in combination with 2,4-D 2 lb/acre or metsulfuron 0.3 lb/acre was evaluated for
effect on growth and injury to Pseudotsuga menziesii, Pinus ponderosa, Tsuga
heterophylla and Abies amabilis seedlings in the Pacific Northwest region. Applications were made at 4 times: 3 month
pre-planting in Dec., as buds began to swell in Mar., during the spring flush
of growth in May, and after bud set in Aug. The effect of different application
rates was of less significance than their timings. Application during active
growth gave unacceptable injury levels; pre-planting caused least injury, but
autumn treatment was acceptable for tolerant species. Species tolerance was in
the order Pinus ponderosa > Pseudotsuga menziesii > T. heterophylla >
A. amabilis.
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3. Brandeis, T.J., M. Newton and E.C.
Cole. 2001. Underplanted conifer seedling survival and growth in thinned
Douglas-fir stands. Canadian-Journal-of-Forest-Research 31(2): 302-312.
Keywords: planting operations
thinning
commercial thinning
site preparation
chemical preparation
release treatments
chemical release
growth
tree/stand health
regeneration
Abstract: In a
multilevel study conducted at the Oregon State University's McDonald-Dunn
Research Forest, Oregon, USA, to determine limits to underplanted conifer
seedling growth, Douglas-fir (Pseudotsuga menziesii), grand fir (Abies
grandis), western redcedar (Thuja plicata) and western hemlock (Tsuga
heterophylla) seedlings were planted in January 1993 beneath second-growth
Douglas-fir stands that had been thinned in 1992 to basal areas ranging from 16
to 31 m2/ha. Understorey vegetation was treated with a broadcast herbicide
(glyphosate + imazapyr) application prior to thinning, a directed release
herbicide (glyphosate, plus triclopyr for tolerant woody stems) application 2
years later, or no treatment beyond harvest disturbance. Residual overstorey
density was negatively correlated with percent survival for all four species.
Broadcast herbicide application improved survival of grand fir and western
hemlock. Western redcedar, grand fir and western hemlock stem volumes were
inversely related to overstorey tree density and this effect increased over
time. There was a strong indication that this was also the case for
Douglas-fir. Reduction of competing understorey vegetation resulted in larger
fourth-year stem volumes in grand fir and western hemlock.
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4. Brandeis, T.J., M. Newton and E.C.
Cole. 2002. Biotic injuries on conifer seedlings planted in forest understory
environments. New Forests 24:1-14.
Keywords: planting operations
site preparation
chemical preparation
release treatments
chemical release
thinning
tree/stand protection
growth
tree/stand health
Abstract: The
effects of partial overstorey retention, understorey vegetation management, and
protective Vexar(R) tubing on the frequency and severity of biotic injuries in
a two-storied stand underplanted with western redcedar (Thuja plicata),
Douglas-fir (Pseudotsuga menziesii), grand fir (Abies grandis), and western
hemlock (Tsuga heterophylla) were investigated. The most prevalent source of
damage was browsing by black-tailed deer (Odocoileus hemionis columbiana); deer
browsed over 74% of Douglas-fir and over 36% of western redcedar seedlings one
or more times over the four years of this study. Neither the spatial pattern of
thinning (even or uneven) nor the density of residual overstorey affected
browsing frequency. Spraying subplots may have slightly increased browsing
frequency, but the resulting reduction of the adjacent understorey vegetation
increased the volume of all seedlings by 13%, whether or not they were browsed.
Vexar(R) tubing did not substantially affect seedling survival, browsing damage
frequency, or fourth-year volume. Greater levels of overstorey retention
reduced frequency of second flushing. Chafing by deer and girdling by rodents
and other small mammals began once seedlings surpassed 1 m in height.
Essentially all grand fir seedlings exhibited a foliar fungus infection.
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5. Busse, M.D., G.O. Fiddler and A.W.
Ratcliff. 2004. Ectomycorrhizal formation in herbicide-treated soils of
differing clay and organic matter content. Water, Air, and Soil Pollution
152:23-34.
Keywords: release treatments
chemical release
growth
tree morphology
tree/stand health
soil properties
mycorrhizal response
Abstract: Herbicides
are commonly used on private timberlands in the western United States for site preparation and control of competing vegetation.
How non-target soil biota respond to herbicide applications, however, is not
thoroughly understood. We tested the effects of triclorpyr, imazapyr, and
sulfometuron methyl on ectomycorrhizal formation in a greenhouse study.
Ponderosa pine, Douglas-fir, and white fir seedlings were grown in four forest
soils ranging in clay content from 9 to 33% and organic matter content from 3
to 17%, and treated with commercial formulations of each herbicide at 0, 1.0,
and 2.0 times the recommended field rate. Many of the possible herbicide-soil
combinations resulted in reduced seedling growth. Root development was
particularly sensitive to the three herbicides, with an average of 51% fewer
root tips compared to the control treatment. The ability of mycorrhizal fungi
to infect the remaining root tips, however, was uninhibited. Mycorrhizal
formation was high, averaging 91% of all root tips, regardless of herbicide,
application rate, soil type, or conifer species. In agreement, soil microbial
biomass and respiratory activity were unaffected by the herbicide treatments.
The results show that these herbicides do not alter the capability of
mycorrhizal fungi to infect roots, even at concentrations detrimental to
seedling growth.
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6. Cole, E.C. and M. Newton. 1987.
Fifth-year response of Douglas-fir to crowding and nonconiferous competition.
Canadian-Journal-of-Forest-Research 17(2): 181-186.
Keywords: release treatments
chemical release
growth
tree morphology
Abstract: Measurements
were made in autumn 1982 in 5-yr-old plantations with trees spaced 17-123 cm
apart, alone or with grass or red alder (Alnus rubra) on 3 site types in the Oregon Coast Range. Crowding and competition from both grass and alder
reduced aboveground dry wt. per tree. Dry wt./ha was
higher at higher tree densities, but this is expected to change with time as
the larger trees at low densities form fully stocked stands. Grass showed the
greatest effect on growth at the driest site. Although red alder decreased
growth on all sites, the effect was most significant at the coastal site where
light is most limiting and moisture least limiting. For the
production of max. individual tree size, low
stocking with control of competing vegetation is recommended.
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7. 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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8. 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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9. 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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10. 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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11. 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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12. 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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13. 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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14. 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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15. 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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16. 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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17. Figueroa, P.F., R.C. Heald and
S.R. Radosevich. 1990. Sensitivity of actively growing Douglas-fir to selected
herbicide formulations. Proceedings-of-the-Western-Society-of-Weed-Science 43:
45-52.
Keywords: release treatments
chemical release
growth
tree/stand health
Abstract: The
results of field studies at 2 sites in Washington and California indicated that
aerial spraying of 2,4-D at 4 lb/acre, triclopyr ester
at 4 lb/acre or 2,4-D + triclopyr ester at 1.2 lb/acre + 0.5 lb/acre to control
red alder [Alnus rubra] led to a significant reduction in Douglas fir
[Pseudotsuga menziesii] growth and survival if applied during periods of active
conifer growth. Herbicides applied singly at high rates caused significantly
more mortality than the herbicides in combination. At both sites, trees had not
fully recovered 5 and 6 years after treatment; damaged trees were at least 1
year behind untreated trees in growth.
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18. Fischer, V.F. and V.F.
Carrithers. 1992. Tolerance of one and two year old douglas-fir seedlings to
triclopyr applications. In
Proceedings-of-the-Western-Society-of-Weed-Science, 10-12-March-1992.
Keywords: release treatments
chemical release
tree/stand health
Abstract: In
field trials conducted near Marquam, Oregon, during 1988-90, the tolerance was evaluated of
douglas-fir [Pseudotsuga menziesii] seedlings to triclopyr ester and triclopyr
amine (both applied at 0.5-1.5 lb/acre) during the 1st 2 years after
transplanting. Triclopyr amine did not cause significant damage to 1- or
2-year-old plants. Triclopyr ester in a water carrier resulted in injury to
terminal buds of 1-year-old plants when applied at 1.5 lb, and in a diesel
carrier resulted in damage to lateral and terminal buds when applied at concn
of <more or =>1.0 lb. Two-year-old plants were more tolerant than
1-year-old plants to both triclopyr formulations, with triclopyr ester at 1.5
lb in a water carrier resulting in only slight needle injury. However, in a
diesel carrier, triclopyr ester at 1.5 lb still resulted in terminal and
lateral bud damage.
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19. Flint, L.E. and S.W. Childs. 1987. Effect of shading, mulching,
and vegetation control on Douglas-fir seedling growth and soil water supply.
Forest-Ecology-and-Management 18(3): 189-203.
Keywords: release treatments
chemical release
manual release
growth
soil properties
Abstract: Harsh environments
on many harvested sites in SW Oregon necessitate site modifications for successful regeneration
of Douglas fir. A 2-yr study was made with 350 seedlings to assess the effects
of 12 soil-surface shading, mulching, and vegetation control techniques on
seedling growth and soil temp. and moisture
environments. Major effects of treatments were to lower soil surface temp.,
reduce soil surface evaporation, and reduce vegetative competition for soil
water. These affected seedlings by adjusting the timing of seedling growth and
reducing soil water loss to increase available water for seedling use. Final
seedling shoot vol. and stem diam. both differed among treatments. Seedlings in
treatments where competing vegetation was controlled showed significantly
greater growth than seedlings in other treatments. Soil water loss in
treatments where either soil surface evaporation was controlled by mulching, or where competing vegetation was controlled, was
significantly less than water loss from the shaded and control treatments. Soil
water loss in treatments with vegetation controlled by herbicide was
significantly less than in treatments with vegetation controlled by scalping.
Seedlings showed greatest growth with treatments that elicited the most
efficient use of available microsite water either by reducing soil surface
evaporation or vegetation competition.
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20. Gourley, M., M. Vomocil and M.
Newton. 1990. Forest weeding reduces the effect of deer-browsing on Douglas
fir. Forest-Ecology-and-Management 36(2-4): 177-185.
Keywords: release treatments
chemical release
tree/stand protection
growth
tree/stand health
Abstract: In
January and February 1981, three-year-old bare-root Douglas fir (Pseudotsuga
menziesii) transplants were established in four clear-felled locations in the Oregon Coast Range where browsing by black tail deer (Odocoileus hemionus
columbiana) was expected. Protection was provided against browsing by 5
physical (rigid protection tube 7.5x75 cm; protective netting, paper budcaps;
leather guard 20x5 cm; and 'Remae' budcaps) and one chemical ('Deer Away')
treatment, each of which was tested with and without complete wood control with
glyphosate. After five years, none of the protective treatments provided any
growth advantages; some even caused growth losses. In contrast, weed control,
with or without additional protective measures, consistently improved growth.
By the 5th year, weeded trees averaged twice the biomass of unweeded trees,
regardless of browsing. Average tree size was largest in the treatment with no
weed competition and with no barriers to prevent browsing. Advantages of
weeding were greatest on the poorest site. Weed control, in conjunction with
the large size of transplants, appeared to prevent most loss due to damage from
moderate deer-browsing.
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21. Haight, R.G. 1993a. The economics of Douglas-fir and red alder management with
stochastic price trends. Canadian-Journal-of-Forest-Research 23(8):
1695-1703.
Keywords: planting operations
site preparation
prescribed fire
release treatments
chemical release
thinning
precommercial thinning
commercial thinning
tree/stand protection
economics
Abstract: A
financial analysis of Douglas fir (Pseudotsuga menziesii) and red alder (Alnus rubra)
management was conducted using yield projections from the Stand Projection
Simulator for the Pacific Northwest region of the United Sates. The analysis included
uncertainty in the price trends and stocking levels of both species following
reforestation. Results from a case study in which Douglas fir price is likely
to increase faster than red alder price show that (i) on more productive sites,
greater regeneration investment is justified to increase the likelihood of
Douglas fir establishment, (ii) on less productive sites, low-cost regeneration
options that produce mixed-species stands have expected present values close to
or greater than a high-cost Douglas fir regeneration effort, (iii) optimal
precommercial removal of red alder depends on mid-rotation prices and
regeneration success, and in many cases growing a mixed-species stand to
maturity produces the highest economic return, and (iv) commercial thinning of
Douglas fir increases the expected present value of the most intensive
regeneration option by up to 10%. The low-cost regeneration options have
relatively high expected returns because of low initial investments and the
presence of two species that may have high values in the future. The
sensitivity of these results to changes in the probability distributions of
regeneration success and price trends is discussed.
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22. Haight, R.G. 1993b. Technology change and the economics of silvicultural investment.
Rocky-Mountain-Forest-and-Range-Experiment-Station,-USDA-Forest-Service General-Technical-Report RM-GTR-232. ii + 18 p.
Keywords: planting operations
site preparation
prescribed fire
release treatments
chemical release
tree/stand protection
thinning
commercial thinning
precommercial thinning
yield
economics
Abstract: Financial
analyses of intensive and low-cost reforestation options are conducted for
loblolly pine (Pinus contorta) stands with broadleaved competition in the
Southern USA, and Douglas fir with red alder (Pseudotsuga menziesii with Alnus
rubra) in the Pacific Northwest. Results show that the expected present values
(EPVs) of low-cost options that result in mixtures of conifers and broadleaves
are superior in some situations to the EPVs of the intensive options.
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23. Harrington, T.B. and J.C.
Tappeiner, II. 1997. Growth responses of young Douglas-fir and tanoak 11 years
after various levels of hardwood removal and understory suppression in southwestern
Oregon, USA. Forest-Ecology-and-Management 96(1/2): 1-11.
Keywords: release treatments
manual release
growth
tree/stand health
Abstract: Douglas fir (Pseudotsuga menziesii) was planted as 2-yr-old bare
rooted seedlings on 2 sites in SW Oregon cleared of old-growth Douglas fir and understorey tanoak
(Lithocarpus densiflorus) in 1980, and broadcast burned in 1981. Planting was
done in 1981 at one site and in 1982 at the second site. Height, diameter, and
crown width of the young Douglas fir and sprout-origin tanoak were measured
1-11 years after reducing the density of the tanoak stand (in 1983, at 2 yr
old) to 0, 25, 50 and 100% of its initial cover. On some of the experimental
plots suppression of understorey vegetation was also carried out. Tanoak cover
developed linearly with time, with steepness of the growth trajectory
increasing at a diminishing rate with increasing percentage of initial tanoak
cover. Fifth-year cover of understorey vegetation declined linearly with
increasing percentage of initial tanoak cover. Survival of Douglas fir
(96-100%) differed little among initial abundances of tanoak, while growth
trajectories for its size became increasingly exponential with decreasing
percentage of initial tanoak cover. Eleventh-year heights of Douglas fir were
similar for 0, 25 and 50% of initial tanoak cover; however, diameter increased
linearly with decreasing percentage of initial tanoak cover, and the slope of
the relationship steepened with understorey suppression. The results indicate
that young stands exhibiting a wide range of stand compositions and
productivities can be established by early manipulations of tanoak and
understorey abundance. Complete removal of tanoak plus understorey suppression
are necessary to maximize Douglas fir growth, while productive, mixed stands
can be achieved by removing 50% or more of tanoak cover.
OSU
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24. 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.
OSU
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25. 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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26. 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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27. Hermann, R.K. and D.P. Lavender.
1999. Douglas-fir planted forests. New-Forests 17(1/3): 53-70.
Keywords: genetic tree improvement
nursery
operations
planting
operations
site
preparation
release
treatments
fertilization
thinning
pruning
tree/stand
protection
growth
yield
Abstract: A
combination of superior wood quality and high productivity has made Douglas fir
(Pseudotsuga menziesii) one of the premier timber trees in the world. As such,
it is grown as a plantation species in several countries in Europe and South America,
and in New Zealand and Australia, as well as throughout its extensive natural range in
western North
America. Decades of
experience with the silviculture of young stands have demonstrated that
practices such as planting, the use of genetically improved seedlings,
precommercial and commercial thinning, and fertilizing may dramatically
increase the yield of industrial products over that of natural forests.
Further, such silviculture is compatible with the production of desired
amenities. Vigorous implementation of such practices wherever Douglas fir is
cultivated will increase the world's timber resources, and be an effective
strategy for reducing the pressure, occasioned by the world's rapidly
increasing population, to harvest the fragile tropical and boreal forests.
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28. 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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29. Jaindl, R.G. and S.H. Sharrow.
1988. Oak/Douglas-fir/sheep: a three-crop silvopastoral system.
Agroforestry-Systems 6(2): 147-152.
Keywords: planting operations
release treatments
manual release
tree/stand health
growth
Abstract: A small
scale agroforestry study started in 1952 was revisited in 1985 to evaluate the
long-term influence of site preparation and grazing on tree growth and survival
in a system with Douglas fir, white oak (Quercus garryana) and sheep. In
1952-53, 2-yr-old Douglas fir seedlings were planted at the rate of 2500
trees/ha under 3 levels of site preparation: (1) no treatment; (2) oak thinned
by 50%; and (3) oak clear felled. From 1954 to 1960, yearling ewes grazed half
of each of the 3 thinning treatments for 3-4 wk each spring. The conifers were
undisturbed since grazing was discontinued in 1960. Survival of planted
conifers averaged 64% in 1985 and did not vary among either site preparation or
grazing treatments. From 1964 to 1985, trees on the thinned and clear felled
plantations grew an av. ht. of 1060 and 990 cm, respectively, compared with 900
cm on the unthinned plantation. D.b.h. averaged 3.8 and 5.6 cm greater on
thinned or clear felled plantations, respectively, than on the unthinned
control by 1985. Conifers on grazed plantations had increased ht. and d.b.h.
growth during the first 12 yr of plantation life, averaging 63 cm taller and
0.7 cm greater in d.b.h. than the ungrazed plots by 1964. By 1985 the
difference in ht. (122 cm) and d.b.h. (1.0 cm) between grazed and ungrazed
plantations was not statistically significant. These data suggest that although
site preparation can positively influence conifer growth, total clear felling
is no better than thinning oaks. Furthermore, proper grazing can increase ht.
and d.b.h. growth of the conifers during and immediately after the grazing
years.
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30. 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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31. 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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32. 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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33. Knapp, W.H., T.C. Turpin and J.H.
Beuter. 1984. Vegetation control for Douglas-fir regeneration on the Siuslaw National forest: a decision analysis. Journal-of-Forestry 82(3): 168-173.
Keywords: planting operations
site preparation
chemical preparation
mechanical preparation
prescribed fire
release treatments
chemical release
manual release
growth
yield
economics
Abstract: Records
from 324 plantations in Oregon were used to calculate the effect on stocking of various
methods of controlling competing vegetation before and after plantation
establishment. A decision tree analysis using 6 management regimes on 5
stocking classes indicated that if no site preparation or release (other than
broadcast burning to reduce fuels) were practised, the forest would produce 63%
of the m.a.i. and 35% of the present net worth (PNW) expected if all means of
control (chemical, manual and burning) were available and used. If only manual
control methods were used 78% of the max. m.a.i. and
57% of the max. PNW would be expected. When all methods except phenoxy
herbicides were available, the expected m.a.i. and PNW were reduced to no less
than 90%. The yield reduction varied with aspect, and the type of prelogging
vegetation. Declines were least on SW-facing sites that were originally
predominantly conifers, and greatest on NE-facing slopes that had supported
broadleaves. Limitations of the analysis are discussed.
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34. Knowe, S.A. 1994a. Effect of competition control
treatments on height-age and height-diameter relationships in young Douglas-fir
plantations. Forest-Ecology-and-Management 67(1-3): 101-111.
Keywords: release treatments
chemical release
manual release
growth
tree morphology
Abstract: Height-age
and height-diameter models for plantations of young Douglas fir (Pseudotsuga
menziesii var. menziesii) were examined in relation to vegetation management
treatments. The models were developed from 10 years of measurements in a
competition release study installed on six sites in the Coast Ranges of Oregon
and Washington. Analysis of height growth patterns for dominant trees indicated
significant differences between the total vegetation control treatment and operational
release treatments or no treatment. The resulting height-age function depicted
exponential growth patterns for the total vegetation control treatment and
nearly linear patterns for the operational release treatment and no treatment.
The height-diameter function was compatible with dominant height growth and
quadratic mean diameter prediction functions. Different height-diameter curve
shapes were associated with total vegetation control and the operational
release and no treatments. The resulting function implied that Douglas fir
trees of a given diameter and age were slightly taller when under interspecific
competition, especially for trees with smaller diameters. The height-age and
height-diameter functions may be used in conjunction with diameter distribution
or stand table projection models developed for these data to predict dynamics
and stand structure in young Douglas fir plantations.
OSU
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35. Knowe, S.A. 1994b. Incorporating the effects of
interspecific competition and vegetation management treatments in stand table
projection models for Douglas-fir saplings.
Forest-Ecology-and-Management 67(1-3): 87-99.
Keywords: release treatments
chemical release
growth
tree morphology
Abstract: A stand
table projection system based on individual-tree and stand-level models for
young Douglas fir (Pseudotsuga menziesii var. menziesii) plantations was
developed from and evaluated with remeasurement data from xeric sites in the
Siskiyou Mountains of SW Oregon (established in a competition gradient study),
and mesic sites in the Coast Ranges of Oregon and Washington (established in a
treatment efficacy study). A projection equation was developed for relative
tree size, defined as the ratio of individual-tree diameter at 15 or 30 cm
above ground level (depending on the study location) to quadratic mean
diameter. The relative size projection equation for the Coast Ranges study included the effect of total vegetation control,
which indicated that diameters of Douglas fir receiving total vegetation
control tended to become more uniform over time in the Coast Ranges. An additional equation was developed to project quadratic
mean diameter so that individual-tree diameters could be estimated from
projected relative size. The effect of vegetation management treatments on
projected quadratic mean diameters in the Siskiyou study was expressed as an
interaction between proportion of cover removed by treatments (intensity) and
dominant height of Douglas fir at time of treatment relative to current
dominant height. In 1- and 2-yr projection periods, the stand table projection
system performed similarly to a diameter distribution prediction system based
on a Weibull distribution function. However, the difference between projected
and predicted diameter distributions became more pronounced as the projection
period increased to 5 years.
OSU
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36. Knowe, S.A. 1994c. Silvicultural and economic value of vegetation
management in the Pacific
northwest. In Weed science education: the cost of
ignorance: Proceedings of the 47th annual meeting of the Southern Weed Science
Society, Dallas, Texas, USA, 17-19 January, 1994. pp. 92-97.
Keywords: planting operations
release treatments
yield
economics
Abstract: Models
indicated that the yield and net present value (NPV) of young Pseudotsuga
menziesii stands in Oregon varied with site index and planting density. Effects of
hardwood competition in 20-year-old plantations were predicted using the
Regional Vegetation Management Model (RVMM). A stand table so produced was used
for developing ORGANON, which simulated silvicultural treatments and growth for
40-60 years. Output from this was used to evaluate the economic consequences of
hardwood competition using ORGECON. It was found that the least impact was
observed at low site index with high planting density. Modifications to the
models are suggested.
37. Knowe, S.A., B.D. Carrier and A. Dobkowski. 1995. Effects of bigleaf
maple sprout clumps on diameter and height growth of Douglas-fir.
Western-Journal-of-Applied-Forestry 10(1): 5-11.
Keywords: release treatments
growth
Abstract:
Diameter and height growth of 7- to 11-yr-old Douglas fir (Pseudotsuga menziesii)
were examined in relation to bigleaf maple (Acer macrophyllum) competition.
Growth models were developed for plantations in Oregon and Washington by joining a distance dependent model with a model that
excluded competition effects. The fitted equations were based on Douglas fir
size at plantation age 7 yr and distance from the stump and crown diameter of
the bigleaf maple clump. The model suggests that bigleaf maple clumps between
5.7 and 14.6 m from planted Douglas firs reduce
the latter's d.b.h. and height growth, and that this reduction becomes greater
with increasing size of the clump. A procedure is suggested to use the models
to guide vegetation management prescriptions on sites with bigleaf maple sprout
clumps.
OSU
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38. Knowe, S.A., T.B. Harrington and R.G. Shula. 1992. Incorporating the
effects of interspecific competition and vegetation management treatments in
diameter distribution models for Douglas-fir saplings.
Canadian-Journal-of-Forest-Research 22(9): 1255-1262.
Keywords: release treatments
manual release
chemical release
growth
tree morphology
Abstract: A
parameter recovery procedure for the Weibull distribution function, based on
diameter percentiles, was modified to incorporate the effects of competing
vegetation in young Douglas fir (Pseudotsuga menziesii var. menziesii)
plantations. The procedure was tested using data from sites in the Coast Ranges
of Oregon and Washington and in the Siskiyou Mountains of SW Oregon. The Coast Ranges study was conducted in 2- to 3-yr-old plantations needing
release from woody shrub (mainly Rubus spectabilis and R. parviflorus) and
broadleaved tree (Alnus rubra and Acer macrophyllum) competition. Release
treatments were an untreated control, manual cutting, triclopyr ester applied
aerially, glyphosate applied aerially, and a total vegetation control treatment
consisting of annual broadcast applications of hexazinone and spot treatments
of glyphosate and triclopyr. The Siskiyou Mountains study was conducted in 1- to 2-yr-old plantations on sites
covered by tanoak (Lithocarpus densiflorus). Tanoak sprout clumps were left
unthinned or were thinned to 50, 25 and 0% of the pretreatment cover. Four
percentiles (0, 25th, 50th, 95th) of the cumulative
probability distribution were predicted as functions of quadratic mean diameter
and age. In the Siskiyou study, cover and total vegetation control affected
quadratic mean diameter and all four percentiles; intensity of the vegetation
treatments affected the 0 and 25th percentiles, and the interaction between
intensity and timing of treatment affected mean diameter. In the Coast Ranges study, only quadratic mean diameter was affected by cover
of woody vegetation, while quadratic mean diameter and the 25th percentile were
significantly affected by total vegetation control. The predicted distributions
showed decreasing variance with increasing cover, particularly in the Siskiyou Mountains. In the Coast Ranges study, the coefficient of variation increased with
increasing cover, indicating that the variance of stem diameters was affected
by average size. On xeric sites in the Siskiyou Mountains, high diameter variability in plots with total vegetation
control suggests that interspecific competition may inhibit the expression of
microsite variation.
OSU
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39. 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.
OSU
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40. Korpela, E.J., S.D. Tesch and R.
Lewis. 1992. Plantations vs. advance regeneration: height growth comparisons
for southwestern Oregon. Western-Journal-of-Applied-Forestry 7(2): 44-47.
Keywords: planting operations
release treatments
growth
Abstract: Model
projections of newly-planted Douglas fir (Pseudotsuga menziesii) seedlings
grown under three competition regimes were compared across three site classes
with growth of three height classes of Douglas fir and white fir (Abies
concolor) advance regeneration for twenty years following overstorey removal
(data from stem analysis of 359 Douglas fir and 344 white fir trees growing in
80 stands in SW Oregon and northern California). It is concluded that, on poor
sites in SW
Oregon, managing
advance regeneration may be a viable alternative to reforestation.
OSU
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41. 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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42. Leininger, W.C. and S.H. Sharrow.
1989. Seasonal browsing of Douglas fir seedlings by sheep.
Western-Journal-of-Applied-Forestry 4(3): 73-76.
Keywords: release treatments
tree/stand health
Abstract:
Controlled sheep grazing for the biological control of unwanted vegetation in
regenerating conifer plantations is an alternative to herbicide application.
Efficient use of livestock to control brush and herbaceous species requires
understanding of potential damage to the tree crop by the grazing animal. Sheep
browsing (700 Columbia ewes May-September 1981, 900 Columbia yearling ewes
May-September 1982) and mechanical damage to 2- to 6-yr-old Douglas fir
(Pseudotsuga menziesii) seedlings were evaluated in the Coast Range of Oregon:
browsing was greatest in May, soon after bud break; little browsing occurred
during July and August. Percentage of study trees with browsed terminal shoots
decreased as seedling height increased above 90 cm. Less than 3% of the study
trees were trampled or received other mechanical damage by sheep. The data
suggest that Douglas fir forests can be grazed by sheep with little or no
damage to conifer regeneration, except in younger plantations in spring.
OSU
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43. Leninger, W.C. 1984.
Silvicultural impacts of sheep grazing in Oregon's
coast range. Dissertation Abstracts International, B: Sciences and Engineering
44(11): 3258.
Keywords: release treatments
growth
Abstract: In
field trials in 1980-2 herded sheep were used to suppress brush in Pseudotsuga
menziesii plantations. Sheep browsing of P. menziesii was highest in May after
bud opening and averaged over 2 years of grazing, the sheep ate 28% of the
current year's growth. Browsing of growing points ceased when seedling height
exceeded the reach of the sheep. Less than 3% of the trees were trampled down.
Two-year-old P. menziesii showed growth damage by sheep but 4- to 6-year-old trees
showed increased growth, possibly due to increased N from sheep excreta. P.
menziesii represented 3% of the annual diet of the sheep, which was composed of
40% graminoids and 40% forbs in young plantations and 70% graminoids and 16%
forbs in older plantations. Sheep weight gains followed seasonal trends typical
of sheep grazing non-irrigated hill pasture in W. Oregon.
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44. McDonald, P.M. and G.O. Fiddler.
1993. Feasibility of alternatives to herbicides in young conifer plantations in
California. Canadian-Journal-of-Forest-Research 23(10): 2015-2022.
Keywords: genetic tree improvement
site
preparation
prescribed
fire
release
treatments
manual
release
chemical
release
growth
economics
Abstract: A
research programme (involving 40 studies) was started in 1980 to compare the
effectiveness and cost of various vegetation management techniques used for
enhancing growth of 1- to 3-yr-old conifer (Pseudotsuga menziesii, Pinus
ponderosa, P. jeffreyi, Abies magnifica and A. concolor var. lowiana)
plantations in California. The studies were ended after 10 yr when competition
became intraspecific. The techniques used included direct methods such as
manual manipulation, mulching, herbicides (Garlon 3A [triclopyr], 2,4-D or
Velpar [hexazinone]), and grazing for releasing conifer seedlings from
undesirable vegetation, and several silvicultural practices (broadcast burning,
group selection, genetically improved seedlings) that serve as indirect methods
for reducing or avoiding vegetation problems. Manual release and mulching were
effective but expensive. Herbicides were effective, applicable to almost all
plant communities, and relatively inexpensive. Grazing was good for cattle and
sheep, but did not significantly enhance conifer seedling growth. Silvicultural
control of weeds was promising, but there was not enough information to
evaluate feasibility. It was concluded that in most instances, forests cannot
be managed economically without herbicides, if the objective is to grow
seedlings at the potential of the site and the plant community includes
sprouting broadleaves and shrubs or rhizomatous forbs and ferns. If the
objective is to create a forest with several age-classes and variable
structure, but with slower seedling growth, longer rotations, and less species
diversity in early seral stages, then it is possible to accomplish this using
other vegetation management techniques.
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45. 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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46. 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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47. McDonald, P.M., G.O. Fiddler and
H.R. Harrison. 1995. Mulching to regenerate a harsh site: effect on Douglas-fir
seedlings, forbs, grasses, and ferns. Pacific-Southwest-Research-Station,
USDA-Forest-Service Research-Paper PSW-RP-222. ii
+ 10 p.
Keywords: release treatments
manual release
growth
Abstract: Douglas
fir (Pseudotsuga menziesii) seedlings, 2+0, were planted in February 1989 on
pastureland in the Arcata District, central coastal California. The tree seedlings were released from a complex
forb-grass-fern community by applying very large (100 ftsuperscript 2) or small
(4 ftsuperscript 2) durable polypropylene mulches one month after planting.
After 5 yr, stem diameter of tree seedlings with large and small mulches was
1.6 and 1.36 inches, respectively. Only seedlings with large mulches were
significantly larger than seedlings on small scalps or control areas.
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48. McDonald, P.M. and O.T.
Helgerson. 1990. Mulches aid in regenerating California and Oregon forests: past, present, and future. Pacific-Southwest-Research-Station,
USDA-Forest-Service General-Technical-Report PSW-GTR-123. ii + 19 p.
Keywords: release treatments
manual release
growth
Abstract: A
discussion of the effects of various types of mulches for controlling seedling
environment in plantations, mostly of Pseudotsuga menziesii and Pinus
ponderosa.
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49. Monleon, V.J., M. Newton, C.
Hooper and J.C. Tappeiner, II. 1999. Ten-year growth
response of young Douglas-fir to variable density varnishleaf ceanothus and
herb competition. Western-Journal-of-Applied-Forestry 14(4): 208-213.
Keywords: site preparation
chemical preparation
release treatments
chemical release
growth
Abstract: The effect
of different densities of varnishleaf ceanothus (Ceanothus velutinus var.
laevigatus) and herbaceous vegetation control on stem diameter, height, and
volume of Douglas-fir (Pseudotsuga menziesii var. menziesii) seedlings was
examined during the 10 yr following planting on a site near Springfield, Oregon, in winter 1996-97. Initial densities of ceanothus ranged
between 0 and 15 000 seedlings/ha and were obtained by interplanting ceanothus
germinants or chemical thinning after clearcutting and broadcast-burning.
Herbaceous vegetation control was achieved by a single application of
glyphosate following planting, with shrub seedlings covered. Ceanothus density
in the range of 0 to 6750 plants/ha did not have an effect on Douglas fir
diameter, height, or volume at age 10; however, Douglas fir growth was
significantly decreased when ceanothus densities reached 15 000 plants/ha. Ten
years after planting, Douglas fir volume in the treatments with <less or
=>6750 ceanothus/ha was 1.7 times greater than that in the 15 000
ceanothus/ha treatment. In contrast, removal of herbaceous vegetation after
planting significantly increased tree diameter, height, and volume, regardless
of ceanothus density. Even 10 yr after application of the treatment, trees
without early herb competition grew faster and had mean dbh, height, and volume
that were 1.02 cm, 0.55 m, and 12.98 dmsuperscript 3/tree
greater respectively than those with herbs. Thus, a treatment at
plantation establishment to control herbaceous vegetation and to reduce
ceanothus density to less than 7000 plants/ha will ensure an increase in growth
and stocking for at least 10 yr.
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50. 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.
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51. 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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52. Newton,
M. and E.C. Cole. 1991. Root development in planted Douglas-fir under varying
competitive stress. Canadian-Journal-of-Forest-Research 21(1): 25-31.
Keywords: planting
operations
release treatments
carbon allocation
growth
Abstract:
Roots of 5-year-old Douglas fir (Pseudotsuga menziesii) on three Oregon
sites were excavated with explosives and analysed for the effects of
competition on root biomass and for planting-induced root deformities. The
plantations were in Nelder designs with graduated spacing from 300 to 15 250
cmsuperscript 2 per tree (about 17x17 to 123x123 cm spacing). Competition
treatments consisted of weed-free intraspecific competition, grass cover seeded
after 1 year of seedling growth, and red alder (Alnus rubra) interplanted 1:1
among the Douglas fir. All plantations were kept at low water stress in year 1.
The ratio of standing aboveground to belowground biomass was the same for each
competition type. Shoot:root
ratios averaged about 4:1, except in severely suppressed trees, where ratios
decreased toward 1:1 in those near death. Neither shoot:root ratio nor tree size was affected by
planting-induced root deformities such as J- or L-rooting, indicating that if
conditions are favourable for 1st-year survival and growth, root deformities at
the time of planting have no subsequent effect on root and shoot development.
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53. 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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54. Newton,
M., E.C. Cole and D.E. White. 1993. Tall planting stock for enhanced growth and
domination of brush in the Douglas-fir region. New-Forests 7(2): 107-121.
Keywords: nursery
operations
site preparation
prescribed fire
release treatments
chemical release
growth
tree/stand health
Abstract:
Two long-term experiments in Oregon
followed the development of planted stock of various sizes, origins, and
species. In one experiment, multi-year comparisons of container, 2+0 bare rooted,
and 3-yr-old Douglas fir (Pseudotsuga menziesii) transplants showed a strong
positive relation between initial height and long-term (10-14 yr) growth under
a range of site conditions with high probability of brush development. In
another experiment, Douglas fir, western hemlock (Tsuga heterophylla), and
Sitka spruce (Picea sitchensis) were planted on brushfield sites (disturbed by
logging 0 and 4 yr previously) where salmonberry (Rubus spectabilis) was or had
been dominant. Half the seedlings were released with glyphosate 6 months after
planting. Western hemlock and Douglas fir bare rooted stock all grew well if
planted in a fresh burn, despite rapid regrowth of salmonberry, but virtually
all seedlings less than 60 cm tall except Sitka spruce were killed by 4-yr-old
salmonberry if not released. Release improved growth of seedlings in the fresh
burn by 6%, gaining an average of about 0.6 year toward reaching a height of 6
m. Release improved growth of survivors in 4-yr-old salmonberry by 51% in height,
72% in diameter, and 325% in volume at age 12 yr. Sitka
spruce grew well until damaged by insects. Western hemlock growth was equal to
or greater than that of Douglas fir of comparable initial height. In all
comparisons, the probability of being overtopped by brush decreased with
increasing initial stock height, and the effect of suppression on growth was
also inversely related to initial height. Tall wilding seedlings had comparable
advantages to nursery-grown seedlings, although Sitka
spruce survival was not reliable.
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55. Newton,
M. and D.S. Preest. 1988. Growth and water relations of Douglas fir
(Pseudotsuga menziesii) seedlings under different weed control regimes.
Weed-Science 36(5): 653-662.
Keywords: release
treatments
chemical
release
growth
soil
properties
tree
physiology
Abstract:
Growth of Douglas fir (P. menziesii) was increased by controlling grasses and
broadleaved weeds with combinations of 4.4 kg atrazine/ha and 2.2 kg 2,4-D or
2,4,5-T during the first 3 years after planting on a well-drained moist site in
the Oregon Coast Range. The greatest growth occurred if weeds were controlled
in the same growing season that tree seedlings were transplanted to the field;
smaller increments came from second- and third-year weed control. Growth
increases attributable to early weed control continued through the fifth year,
indicating that conditions during establishment strongly influenced later
growth. Plots with no herbaceous vegetation had more available soil water than
those with competing vegetation, and tree seedlings on these plots experienced
less water stress. Irrigation in the third year increased stem diameter of
seedlings in that year but had no effect thereafter. Increases in average
seedling stem volume at 5 years after transplanting were linearly related to the
difference in observed xylem potential during the first three seasons after
transplanting and the xylem potential at which photosynthesis ceased, -2 MPa.
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56. Newton,
M., D.S. Preest and D.E. White. 1987. Effect of relieving moisture stress with
extended weed control in Douglas-fir.
Proceedings-of-the-Western-Society-of-Weed-Science (Vol.40): 129-130.
Keywords: release
treatments
chemical release
growth
tree physiology
soil properties
photosynthesis
Abstract:
The growth of Douglas fir Pseudotsuga menziesii seedlings was increased during
the first 5 years by controlling grasses and forbs in 7 herbicide regimes
during the 1st 3 years, the effect diminishing with time after planting.
Devegetated plots had more available moisture through the growing season than
those with Agrostis tenuis or mixed mixed grass/forb cover dominated by A.
tenuis or Hypochaeris radicata. Tree moisture stress followed soil moisture but
only after allowing for large fluctuations of diurnal stress. Weed control
relieved moisture stress in trees. P. menziesii photosynthesis tended to shut
down in the region of -2.0 MPa moisture stress. For the 1st 3 years in a
favourable coastal environment approx. 1700 MPa-h above -2.0 MPa was estimated
to be required for survival. Increments of moisture beyond that would
contribute significantly to growth.
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57. Pabst, R.J., J.C. Tappeiner, II and M. Newton. 1990. Varying
densities of Pacific madrone in a young stand in Oregon
alter soil water potential, plant moisture stress, and growth of Douglas fir.
Forest-Ecology-and-Management 37(4): 267-283.
Keywords: release
treatments
manual release
soil properties
tree physiology
growth
Abstract:
In a study to evaluate the effects of mixed conifer/broadleaf stands on
soil water potential, and Douglas fir (Pseudotsuga menziesii) moisture stress
and growth, Pacific madrone (Arbutus menziesii) and associated shrub and
herbaceous vegetation were thinned to represent the following range of
conditions: high-density madrone (H) with associated shrubs and herbs
controlled; medium-density madrone (M), shrubs and herbs controlled;
low-density madrone (L), shrubs and herbs controlled; no madrone (N), shrubs
and herbs controlled; and no madrone (U), shrubs and herbs predominate. The
study was carried out in 1985 and 1987 at a 2-ha droughty site in the Klamath
Mountains, SW Oregon, planted in 1979 with 2+0 Douglas fir. Soil
water-potential ( psi ) at a depth of 0-30 cm was
consistently higher in treatment N than in all other treatments; in 1987 this
difference was significant (P<0.025). Average psi in treatment U reached
-1.5 MPa (permanent wilting point) between June and July in both years of the
study, whereas in the other treatments that level was never reached. Soil water
conditions were also relatively severe in treatment H. Predawn plant moisture
stress (PMS) of Douglas fir was significantly (P=0.0001) less in treatment N
than in all other treatments. Seasonal moisture-stress relief (SMSR) of Douglas
fir was significantly related to madrone leaf area index (LAI) and was greatest
in treatment N. Seasonal moisture stress relief of madrone was also
significantly correlated with LAI. There were highly significant linear
relationships between both predawn and midday PMS and soil water potential
for Douglas fir and madrone. Results clearly show that conditions for maximum
Douglas fir growth occurred in treatment N. Average diameter growth of Douglas
fir was greatest in treatment N, although not significantly different from that
in treatment U, and least in treatment H. In 1987, Douglas fir growth in
diameter, stem basal area, and stem volume was strongly related to SMSR and
madrone LAI, and to a lesser extent, seasonal soil tension relief.
OSU
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58. Perry, D.A., C. Choquette and P. Schroeder. 1987. Nitrogen
dynamics in conifer-dominated forests with and without hardwoods.
Canadian-Journal-of-Forest-Research 17(11): 1434-1441.
Keywords: release
treatments
soil properties
tree morphology
Abstract:
In studies on the E. slopes of the Oregon Coast Range, contents of N
and C in the surface 12 cm of mineral soil, N in leaf litterfall, anaerobic N
mineralization rates in the soil and forest floor, and root and N accretion to
sand traps placed in surface soil layers were studied in stands dominated by
Douglas fir trees, from which the broadleaved component had been partially or
completely removed during thinning 3 yr earlier. Contrary to expectations,
stands without broadleaved species had more N in mineral soil, a greater rate
of anaerobic soil N mineralization and a lower soil C :
N ratio than stands with broadleaved species. These variables did not differ
between thinned and unthinned mixed stands. From litterfall and sand trap data,
it is suggested that N was redistributed in the coniferous system after removal
of the broadleaved species.
OSU
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59. Petersen, T.D. and M. Newton. 1983. Growth of Douglas-fir
following release from snowbrush and forbs in the Oregon Cascades.
Proceedings-of-the-Western-Society-of-Weed-Science (Vol. 36):58-59.
Keywords: release
treatments
chemical release
growth
Abstract:
Ceanothus velutinus and other weeds such as Epilobium angustifolium,
Rubus ursinus and Pteridium aquilinum suppressed the growth of Douglas fir in
plantations of the central Cascades of W. Oregon. Stem vol. increases of
Douglas fir after 4 yr were greatest when all competing vegetation had been
controlled for 1 growing season with herbicides. It is suggested that C.
velutinus competes with Douglas fir by depleting soil moisture although the
cause of competition by other weeds is unknown. The best time for releasing
Douglas fir from competition is discussed.
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60. Petersen, T.D., M. Newton and S.M. Zedaker. 1988. Influence of
Ceanothus velutinus and associated forbs on the water stress and stemwood
production of Douglas-fir. Forest-Science 34(2): 333-343.
Keywords: release
treatments
chemical release
tree physiology
soil properties
growth
Abstract:
In studies in the central Cascade Mts., Oregon, three regimes were
established in 1978 around individual trees in four 5-yr-old and four 10-yr-old
stands, viz. no treatment (control), elimination of C. velutinus with 2,4-D or
elimination of C. velutinus and forbs with 2,4-D and glyphosate. Seasonal and
diurnal variation in stem and soil water potentials were measured during 1979.
Soil water potential during late summer was <-1.5 MPa at depths of 10, 40
and 100 cm on control plots and at depths of 10 and 40 cm in 5-yr-old stands
and 10 cm in 10-yr-old stands in plots where only C. velutinus was eliminated.
In the absence of shrubs and forbs, soil water potential at 100 cm was near
field capacity throughout the season. Predawn stem water potential during late
summer was significantly lower on control plots than on the treatment plots for
all 5-yr-old stands and for two of the 10-yr-old stands. By 1986, tree stems
were 2-6 cm larger in basal diam. and 1-2 m taller in the absence of
competitors. The increase in stem size was greater in the stand treated at 5 yr
old than in that treated at 10 yr old. The correlation between growth and water
stress suggests that interspecific competition for soil water during summer
drought is a limiting factor in stemwood production.
OSU
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61. Prasad, R. 2000. Some aspects of the impact and
management of the exotic weed, Scotch broom (Cytisus scoparius (L.) Link) in British Columbia, Canada. Journal-of-Sustainable-Forestry
10(3/4): 341-347.
Keywords: release
treatments
manual release
growth
photosynthesis
Abstract:
A recent cutover area near Maple
Mountain,
Duncan,
British Columbia,
was planted with 2+1 Douglas fir (Pseudotsuga menziesii) seedlings in 1994.
Scotch broom (Cytisus scoparius) invaded the site rapidly. Growth (height and
root collar diameter) of Douglas fir seedlings was monitored for 2 years on
uncleared plots and on plots where the dense canopy of broom was manually cut
and completely removed. Results showed that the broom reduced
photosynthetically active radiation by 71% and growth of Douglas fir by 45-46%.
Formulations of 3 fungal pathogens (Fusarium tumidum, Pleiochaeta setosa,
Chondrostereum purpureum) were tested in a greenhouse for their effects on
growth of Scotch broom seedlings. Only F. tumidum was effective, suppressing
the growth of 1-, 3- and 6-month-old seedlings.
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62. Price, D.T., T.A. Black and F.M. Kelliher. 1986. Effects of salal
understory removal on photosynthetic rate and stomatal conductance of young
Douglas-fir trees. Canadian-Journal-of-Forest-Research 16(1): 90-97.
Keywords: release
treatments
manual release
photosynthesis
tree physiology
soil properties
growth
Abstract:
Studies were made in a thinned 32-yr-old Douglas fir stand on a
drought-prone site on the E. coast of Vancouver
Island. Four pairs of similar trees were selected and
the salal (Gaultheria shallon) understorey was removed completely from around
one of each pair. The root zones of each tree were isolated using plastic
sheeting buried to bedrock. Photosynthesis, stomatal conductance, soil water
potential and canopy microclimate were measured intensively in one pair on 4
clear days during an extended dry period in June 1982. B.a. increment of the four pairs of trees was
measured over 3 growing seasons. To determine the effect of soil water potential
on tree photosynthesis, the same variables were measured for 3 consecutive days
in Aug. 1982 for another tree initially subjected to a soil water potential of
approx. -1.6 MPa, but irrigated to approx. -0.02 MPa between days 1 and 2.
Solar irradiance decreased markedly between days 2 and 3, thus creating a
unique data set. Results showed that removal of the understorey significantly
increased rates of photosynthesis in Douglas fir, both diurnally and
seasonally. Photosynthesis was not generally limited by stomatal conductance
unless vapour pressure deficit was high and photon flux density was saturating.
Improved tree growth after understorey removal was due to the increased soil
water potential that increased both photosynthetic capacity and stomatal conductance.
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63. 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.
OSU
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Link
64. 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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Link
65. Roberts, S.D., C.A.
Harrington and T.A. Terry. 2005. Harvest residue and competing vegetation
affect soil moisture, soil temperature, N availability, and Douglas-fir
seedling growth. Forest-Ecology-and-Management 205(1/3): 333-350.
Keywords: site
preparation
chemical preparation
release treatments
chemical release
soil properties
growth
tree physiology
Abstract:
Decisions made during stand regeneration that affect subsequent levels
of competing vegetation and residual biomass can have important short-term
consequences for early stand growth, and may affect long-term site
productivity. Competing vegetation clearly affects the availability of site
resources such as soil moisture and nutrients. Harvest residues can also affect
the availability of site resources. We examined second and third year seedling
performance of a Douglas fir (Pseudotsuga menziesii) plantation with different
vegetation control and biomass retention treatments on a highly productive site
in the coast range of Washington, USA. Treatments included a bole-only harvest
without vegetation control (BO-VC), a bole-only harvest with complete
vegetation control (BO+VC), and a total tree harvest with complete vegetation
control that also included removal of all coarse woody debris and harvest
residues (TTP+VC). The VC treatment involved: (a) in the first year, broadcast
application of Oust and Accord concentrate applied with a surfactant 2 weeks
before planting; (b) in the second year, a March broadcast application of
Atrazine and a directed spot-spray of Accord Concentrate on the vegetation
between rows in April-May; and (c) in the third year, a March broadcast
application of Atrazine and Oust, a direct spot-spray application of Accord
Concentrate, and a spot-spray of Transline with surfactant on April-May to
control persistent shrub species. The study was conducted to determine if
vegetation control and residue retention treatments affected soil moisture,
soil temperature, and apparent nitrogen (N) availability, and whether these
differences in site resources were correlated with seedling size and growth. In
both second and third growing seasons, volumetric soil moisture at 0-20 cm
depth was lowest on plots that did not receive vegetation control (BO-VC).
Seedlings on these plots also had the lowest diameter and volume growth. In
year 2, which was fairly moist, volume growth on TTP+VC plots was slightly
higher than on BO+VC plots. TTP+VC plots did have lower soil moisture, but soil
temperatures were slightly warmer. In year 3, a drier year, growth was greatest
on BO+VC plots, which had consistently higher soil moisture levels. Apparent N
availability in year 3 also varied with vegetation control. Douglas fir foliar
N concentrations averaged 2.3% on the plots where competing vegetation was eliminated, compared to 1.8% on plots where competing
vegetation was not controlled. Douglas fir foliar N concentrations did not
differ between residue retention treatments, although N concentrations of
competing vegetation were higher where residual biomass was retained. Higher
apparent N availability was correlated with greater seedling growth. Based on
the results from years 2 and 3, it appears that soil moisture, particularly
late in the growing season, had the greatest effect on seedling growth in both
years. Available N may also have played a role, although the effects of N
cannot be completely separated from those of soil moisture. When soil moisture
is adequate, it appears that available N and soil temperature exert greater influence
on growth. Vegetation control and residue retention can influence all 3 of
these factors. The relative importance of each factor may depend on the
year-to-year variation in environmental conditions.
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66. Rose, R. and J.S. Ketchum. 1998. Early results of the 'Herb II'
study: evaluating the influence vegetation control has on fertilization at the
time of planting. In Proceedings of the Annual Meeting of the Western
Society of Weed Science, Waikoloa, Hawaii, 10-12 March, 1998. pp. 55-59.
Keywords: release
treatments
chemical release
fertilization
growth
Abstract:
Field trials were conducted at 5 sites in the Pacific Northwest region of the
USA to assess the interactive effects between increasing levels of control of
deerbrush (Ceanothus integerrimus), snowbrush (C. velutinus), black cottonwood
(Populus trichocarpa), Scotch broom (Cytisus scoparius), Portuguese broom (C.
striatus), trailing blackberry (Rubus sp.), thimbleberry (R. parviflorus) and
salmonberry (R. spectabilis) with hexazinone or sulfometuron, and fertilizer
treatments using slow release briquettes of N:P:K at 14:3:3 or 9:9:4 applied at
planting for Douglas fir (Pseudotsuga menziesii), ponderosa pine (Pinus
ponderosa), western hemlock (Tsuga heterophylla) and coastal redwood (Sequoia
sempervirens). Results indicated that at all but one site, weed control +or-
fertilizer led to increased tree growth, while at the fifth site weed control +
fertilizer gave the greatest growth. Fertilizer alone did not increase growth
at any site.
Non-OSU
Link
67. 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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68. 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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69. 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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70. Roth, B.E. and M. Newton. 1996a. Role of Lammas
growth in recovery of Douglas-fir seedlings from deer browsing, as influenced
by weed control, fertilization, and seed source.
Canadian-Journal-of-Forest-Research 26(6): 936-944.
Keywords: planting
operations
release treatments
chemical release
fertilization
tree/stand protection
growth
tree/stand health
Abstract:
This study examined the effects of weed control, nitrogen fertilizer,
and seed source on Lammas growth (second flushing) in Douglas fir (Pseudotsuga
menziesii) seedlings on 3 sites in the Oregon
Coast
Range.
It also assessed the occurrence of deer (Odocoileus hemionus columbianus)
browsing as related to these silvicultural treatments and examined the role of
Lammas growth in seedling recovery and escape from deer browsing. Seedlings
(averaging 54 cm tall, 6 mm diameter at 15 cm above ground) were planted in
February 1992, and measured at the time of planting and in autumn 1992 and
1993. Complete weed control with hexazinone (annual applications + spot treatments
as necessary) significantly increased the occurrence of Lammas growth. Nitrogen
fertilizer (220 kg/ha urea) decreased Lammas growth significantly, at least in
part by favouring weed growth. Lammas growth was not influenced by seed source
(genetically improved from a seed orchard or local wild stock). The increased
Lammas growth associated with weed control mediated the effects of deer
browsing. Although multiple-year browsing occurred more commonly on weeded than
unweeded seedlings, after two growing seasons weeded seedlings that were
repeatedly browsed were twice as large as unbrowsed, unweeded seedlings. On one
site, stock of wild origin was more heavily browsed than that from a seed
orchard.
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71. Roth, B.E. and M. Newton. 1996b. Survival and
growth of Douglas-fir relating to weeding, fertilization, and seed source.
Western-Journal-of-Applied-Forestry 11(2): 62-69.
Keywords: planting
operations
fertilization
release treatments
chemical release
growth
tree physiology
tree morphology
tree/stand health
Abstract:
The goal of this study was to quantitatively evaluate the individual
and interactive effects of weed control, nitrogen fertilizer, and seed source
on Douglas fir (Pseudotsuga menziesii) survival and growth in plantations on a
range of sites and growing conditions in western Oregon.
Weed control with hexazinone (broadcast application after planting) was the
dominant factor influencing seedling survival and growth and accounted for 49%
of the explained variation in seedling volume after 2 years. Nitrogen
fertilizer (urea) had no effect when used in conjunction with weed control and
a negative effect when used without weed control. Seedlings from a seed orchard
source were significantly larger in diameter and volume than those from a wild
local source after two growing seasons, but second-year heights were similar
for the two seedling types. Initial seedling size was positively correlated
with growth rate.
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72. Sharrow, S.H., D.H. Carlson, W.H. Emmingham and D.P. Lavender.
1992a. Direct impacts of
sheep upon Douglas-fir trees in two agrosilvopastoral systems.
Agroforestry-Systems 19(3): 223-232.
Keywords: release
treatments
tree/stand health
Abstract:
Livestock may provide important service and production functions in
agroforestry systems. However, use of livestock in conifer/improved pasture
agrosilvopastoral [silvopastoral] systems is currently limited by concerns
about potential damage to trees by livestock. The effects of sheep grazing on
Douglas fir (Pseudotsuga menziesii) trees in two patterns of
sheep/pasture/conifer agroforest (cluster and grid plantations) at a site near
Corvallis, Oregon, were studied from 4 yr after planting (1983) until the first
precommercial thinning at 10 yr old (1988). The plantations had been
established in 1979 using 2+0 Douglas fir seedlings planted as 5-tree clusters
in 1.5 m diameter circles 7.7 m apart (840 trees/ha) and as a standard square
grid of single trees 2.5 m apart (1600 trees/ha). In 1982, half of the
plantations were rototilled and sown with inoculated Trifolium subterraneum.
Trees averaged >1 m in height when grazing began in summer 1983. Some
browsing of tree lateral branches by sheep occurred regardless of grazing
season in 1983-85. However, the 2-10% of current year's lateral branch growth
removed by grazing sheep was too low to affect tree growth. Sheep removed the
terminal leaders from only 3-9% of trees each year during 1983-85. Most
browsing of terminals occurred in the summer when other forages had become
mature and were relatively unpalatable to sheep. Less than 13% of agroforest
trees were barked by sheep each year during 1983-87. By the end of grazing in
1987, <8% of agroforest trees had sustained a level of barking likely to
affect future growth (>50% of tree circumference barked). Mean forage
utilization was greater in the cluster plantations, while browsing, barking and
tree damage was greater in the grid plantations. Grazing had no discernible effect
on tree diameter or height in any year (P > 0.05). Total tree mortality
attributable to sheep grazing during 1983-87 was only 0.9%, including three
trees girdled by sheep and two barked trees which were subsequently attacked by
insects. Overall, grazing had no detrimental effect on timber stand growth or
mortality.
OSU
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73. 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.
OSU
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74. 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.
OSU
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75. 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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76. 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.
OSU
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77. Sumaryono and G. Crabtree. 1989. Differential tolerance of woody
nursery crop seedlings to napropamide. Weed-Technology 3(4): 584-589.
Keywords: nursery
operations
release treatments
chemical release
tree/stand health
Abstract:
Field studies at Corvallis, Oregon and greenhouse experiments were
conducted to evaluate the tolerance to napropamide of black locust (Robinia
pseudoacacia), honeylocust (Gleditsia triacanthos), apple, Douglas fir
(Pseudotsuga menziesii), ponderosa pine (Pinus ponderosa) and Japanese black
pine (Pinus thunbergii) in the seedling stage. Deciduous species were more
susceptible to napropamide than coniferous species. Apple had the slowest seed
germination and root development and was more susceptible. The deciduous
species had more secondary roots in the shallow soil layer which contained most
of the herbicide than the coniferous species. The roots of all woody species
tested in vitro were inhibited significantly by contact with the herbicide, but
only shoot growth of apple and black locust was inhibited. Injury to woody
nursery crop seedlings may be avoided by delaying herbicide application.
OSU
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78. Tung, C.H., J. Batdorff and D.R. DeYoe. 1986a. Survival and growth of Douglas-fir seedlings with
spot-spraying, mulching and root-dipping.
Western-Journal-of-Applied-Forestry 1(4): 108-111.
Keywords: nursery
operations
release treatments
chemical release
manual release
tree/stand health
growth
Abstract:
In trials near Coos
Bay, Oregon,
480 bare-rooted 2+0 Douglas fir seedlings, half of which had roots treated with
Terra Sorb (a hydrolysed starch material capable of absorbing large amounts of water),
were planted on a harsh site where several regeneration attempts had failed.
After planting, seedlings received no further treatment, or glyphosate or paper
mulch were applied around seedlings for 1 or 2 yr. Root dipping in Terra Sorb
did not enhance survival or growth. Survival was significantly greater after
the third season when competing vegetation was controlled with mulch or
glyphosate during the first one or two seasons. Survival of seedlings treated
twice with glyphosate was 26, 23 and 21% greater, respectively, than seedlings
receiving one glyphosate treatment and one or two mulch applications. Ht.
growth was n.s.d. among treatments.
OSU
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79. 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.
OSU
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80. Walstad, J.D., J.D. Brodie, B.C. McGinley and C.A.
Roberts. 1986. Silvicultural value of chemical brush control in the management of
Douglas-fir. Western-Journal-of-Applied-Forestry 1(3): 69-73.
Keywords: release
treatments
chemical release
growth
yield
economics
Abstract:
Retrospective analyses were made of 3 Douglas fir plantations (age
12-39 yr) in western Oregon
and Washington,
to determine the long-term silvicultural effects and economic value of chemical
brush control 10-25 yr earlier. Stocking and growth of Douglas fir were
significantly greater on areas that received at least one aerial application of
2,4-D or 2,4,5-T than on
untreated areas. On two sites, invading Alnus rubra virtually excluded Douglas
fir in the absence of brush control. On the third site, Ceanothus velutinus
var. laevigatus reduced Douglas fir stocking and diam. growth on untreated
areas. On all three sites, projections of mature yield and economic returns
based on current stand conditions indicated substantial benefits for areas
where brush control treatments were applied.
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81. Wang, Z., M. Newton and J.C. Tappeiner, II. 1995. Competitive
relations between Douglas-fir and Pacific madrone on shallow soils in a
Mediterranean climate. Forest-Science 41(4): 744-757.
Keywords: release
treatments
manual release
soil properties
growth
Abstract:
A large area of Pacific
Coast
forests is characterized by shallow soil, with negligible rainfall in the
growing season. The availability of bedrock water and its effects on growth and
ecophysiology of 11-yr-old planted Douglas fir (Pseudotsuga menziesii) and
sprouting Pacific madrone (Arbutus menziesii) was studied. The study was
carried out at 3 regulated densities (0, 330 or 1322 clumps/ha) of madrone
sprouts on shallow (<50 cm) residual soils in the Klamath Mts of SW Oregon.
Total bedrock water depleted from March to September, as observed in drill
holes by neutron probe, and did not suffer significantly among the 3 densities
of madrone sprouts. However, cover in plots with the highest density of madrone
depleted 50 mm of water from the 1.5 m layer by June, whereas vegetation on
lower density treatments withdrew 15-28 mm by June, with later withdrawal
distributed more uniformly through the growing season. Madrone density
significantly affected basal diameter and height growth of Douglas fir. Madrone
was consistently taller than Douglas fir in all plots. The height of 11-yr-old
madrone sprout clumps (424-465 cm) did not differ significantly among
densities. Madrone leaf area index and biomass were higher at the high density
of madrone than at medium density. Physiological advantages and rooting habits
of madrone give it a competitive advantage over Douglas fir at this site, that it might not have if
bedrock did not provide the principal water reservoir for summer growth.
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82. 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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83. 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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84. 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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85. 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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86. Woods, J.H., D. Kolotelo and A.D. Yanchuk. 1995. Early selection
of coastal Douglas-fir in a farm-field test environment. Silvae-Genetica 44(4):
178-186.
Keywords: genetic
tree improvement
planting operations
site preparation
mechanical preparation
release treatments
chemical release
manual release
genetic relationships
wood quality
growth
Abstract:
Farm-field tests are progeny tests established using intensive site
preparation, close spacing and nearly complete weed control. Early growth and
wood density of coastal Douglas-fir (Pseudotsuga menziesii) in a farm-field
environment for up to 7 years from seed were compared with stem volume and wood
density from 11 field sites at age 13 (20-25 of commercial rotation). The
farm-field test material comprised 70 full-sib families from six 6-tree
half-diallels (some reciprocals and missing crosses) without selfs. Parent
trees were from natural stand selections in the coastal area of British
Columbia, Canada,
and the farm-field test was conducted on southern Vancouver
Island. Family heritabilities were high for almost all
traits in both the farm-field and field sites. Breeding-value correlations of
farm-field heights with field stem volume at age 13 increased from a low of 0.5
for farm-field age 1 and levelled off at about 0.7 by farm-field age 3.
Farm-field diameter with field volume age 13 breeding-value correlations were
initially lower than those for height, but increased to 0.82 by age 7. Wood
density breeding value correlations between field pilodyn assessments at age 13
and farm-field stem sections at age 6 were 0.83. Maximum family-selection
efficiency per year (including a 5-year breeding delay), relative to direct
selection on field volume 13, reached 162% using index selection on farm-field
height and diameter at age 3. Within-family selection efficiencies per year
were highest at age 1 and declined quickly thereafter. All selection in the
farm-field test had a higher efficiency per unit time than selection in field
tests. It is concluded that correctly established farm-field tests will provide
greater per year gains in stem yield and wood density traits than field sites.
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