1. Cole, E.C. and M. Newton. 1989a. Height growth response in Christmas trees to sulfometuron and other herbicides. Proceedings-of-the-Western-Society-of-Weed-Science (Vol. 42): 129-135.

Keywords:      release treatments

                        chemical release

                        growth

                        tree/stand health

                        stand conditions

Abstract: Abies procera, A. grandis and Pseudotsuga menziesii cv. Menziesii were evaluated for tolerance to sulfometuron (0.05-0.21 kg/ha), atrazine (4.5 kg/ha) and hexazinone (2.2 kg/ha). Herbicides were applied pre-budbreak and sulfometuron was also applied post-budbreak. Weeds were suppressed equally effectively by all rates and herbicides pre-em. Low rates of sulfometuron were less effective post-em. There was no significant damage to A. procera seedlings, although the highest rate of sulfometuron slowed growth significantly. A. grandis was not affected by any treatment. All treatments caused injury to 1-year-old P. menziesii, primarily needle chlorosis and slight stunting. Growth was best in atrazine-treated plots. For 3-year-old P. menziesii, injury was not significant but high rates of sulfometuron caused cosmetic damage. Best growth was observed with hexazinone and worst with sulfometuron. Post-budbreak applications and high rates of sulfometuron reduced growth more than pre-budbreak application and low rates.

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2.
Cole, E.C. and M. Newton. 1989b. Seasonal efficacy comparison of two glyphosate formulations. Proceedings-of-the-Western-Society-of-Weed-Science (Vol. 42): 136-142.

Keywords:      release treatments

                        chemical release

                        tree/stand health

                        stand conditions

Abstract: Glyphosate formulations with 13% (Roundup) and without (Accord) surfactant were compared at 0.84 and 1.68 kg/ha, applied June-Oct. against Alnus rubra, Rubus spectabilis, R. parviflorus, R. ursinus and Pteridium aquilinum in a Pseudotsuga menziesii cv. menziesii plantation. No differences in efficacy between the two formulations against any species were noted. All species were controlled better by high rates of herbicide. R. spectabilis and R. parviflorus were controlled <less or =>100%, although July applications were least effective. A. rubra was reduced <less or =>80% and early application gave best control. Rates of application had less effect on Pteridium aquilinum control (<less or =>98%), and Oct. applications were least effective. Damage to Pseudotsuga menziesii was worst with June applications and decreased through the year. Oct. treatment caused negligible damage.

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3.
Cole, E.C., M. Newton and D.E. White. 1986. Response of northwestern hardwoods, shrubs, and Douglas-fir to Arsenal and Escort. Proceedings-of-the-Western-Society-of-Weed-Science (Vol.39): 93-101.

Keywords:      release treatments

                        chemical release

                        tree/stand health

                        stand conditions

Abstract: Arsenal (imazapyr) and DPX-T6376 (metsulfuron) were evaluated for scrub control in Pseudotsuga menziesii plantations at 3 sites in Oregon in 1984-85. Arsenal produced the most complete and consistent control of Acer macrophyllum when applied in late summer, but early summer applications were more effective against the sclerophyll brush species Arbutus menziesii, Ceanothus velutinus var. laevigatus, Arctostaphylos columbiana and A. viscida. High rates of Arsenal gave good control of Alnus rubra and Rubus spectabilis, but did not control R. laciniatus or R. procerus. On all the controlled species, growth of new foliage was decreased or prevented. DPX-T6376 reduced the crown vol. of A. macrophyllum and killed the sclerophyll brush species, all Rubus spp. but not A. rubra. Both chemicals produced severe injury to P. menziesii.

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4.
Cole, E.C., M. Newton and D.E. White. 1988. Efficacy of imazapyr and metsulfuron methyl for site preparation and conifer release in the Oregon Coast Range. Forest-Research-Laboratory,-Oregon-State-University Research-Note 81. 7 p.

Keywords:      release treatments

                        chemical release

                        tree/stand health

                        stand conditions

Abstract: Imazapyr (Arsenal) and metsulfuron methyl (Escort) were tested at 3 rates for controlling shrubs in young Douglas fir (Pseudotsuga menziesii) plantations on 3 sites in the Oregon Coast Range. Imazapyr was highly effective on red alder (Alnus rubra) and bigleaf maple (Acer macrophyllum), but was less effective on salmonberry (Rubus spectabilis) and other blackberry (Rubus) species. Metsulfuron-methyl was ineffective on red alder and bigleaf maple, but gave excellent control of salmonberry, Himalaya blackberry (R. procerus) and evergreen blackberry (R. laciniatus). Both chemicals caused severe injury to Douglas fir seedlings, especially when applied during the growing season. It is concluded that these herbicides are promising for site preparation, but have limited use for release of Douglas fir.

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5. DeBell, D.S. and T.C. Turpin
. 1989. Control of red alder by cutting. Pacific-Northwest-Research-Station,-USDA-Forest-Service Research-Paper PNW-RP-414. ii + 10 p.

Keywords:      release treatments

                        manual release

                        stand conditions

Abstract: Effects of tree age, month of cutting, and height and angle of the cut on sprouting of red alder (Alnus rubra) stumps were evaluated in a study designed to develop an effective method for controlling red alder in Douglas fir (Pseudotsuga menziesii) plantations in the Oregon Coast Range.

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6.
Dimock, E.J., II and E.B. Collard. 1981. Postplanting sprays of dalapon and atrazine to aid conifer establishment. Pacific-Northwest-Forest-and-Range-Experiment-Station,-USDA-Forest-Service Research-Paper PNW-RP-280. iii + 16 p.

Keywords:      release treatments

                        chemical release

                        growth

                        tree/stand health

                        stand conditions

Abstract: A mixture of dalapon and atrazine at 8 and 4 lb/acre, respectively, or dalapon or atrazine alone were applied to control perennial grasses and forbs competing with newly planted seedlings of ponderosa pine and Douglas fir. In 4 studies in Oregon in 1975, herbicides were spot sprayed around individual seedlings. In 2 studies in Washington and Oregon in 1976, herbicides were broadcast sprayed. The mixture consistently controlled grass and forbs better than either herbicide alone, reducing grass and forb cover respectively by 80-82% and 48-58% in the first year. Control persisted for 2-4 yr. Varying results are reported as to the effects of the different treatments on height growth and survival.

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7.
Drever, C.R. and K.P. Lertzman. 2003. Effects of a wide gradient of retained tree structure on understory light in coastal Douglas-fir forests. Canadian-Journal-of-Forest-Research 33(1): 137-146.

Keywords:      thinning

                        stand conditions

Abstract: We characterize understorey light of seven stands that varied along a gradient of tree retention. Using hemispherical canopy photographs and digital image, we estimated gap light or solar radiation reaching the understorey through the canopy. Using nonlinear regressions, we related gap light to several structural attributes in the examined silvicultural treatments. The silvicultural treatments affected both the median and range of gap light in the understorey. As overstorey removal increased from uncut second growth to green-tree retention, the median value of light increased from 8 to 68% full sun, while the range of light increased from 3-22% to 26-88% full sun. We found strong, significant, and negative nonlinear relationships between gap light at a particular microsite (0.04 ha) in the understorey and the height, diameter at breast height, density, and volume of surrounding retained trees (ra2=0.77-0.94). These relationships can aid planning of treatments that retain forest structure, such as variable retention, by allowing predictions of understorey light from commonly used field data. These predictions allow forest managers to understand some of the ecological consequences and tradeoffs associated with retaining structure during harvesting.

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8.
Feller, M.C. 1990. Herbicide application followed by prescribed fire to convert a brushfield into a conifer plantation in south coastal B.C.: a combination of the initial effects of two treatments. B.C. Ministry of Forests FRDA Report 146. 40 p.

Keywords:      site preparation

                        chemical preparation

                        prescribed fire

                        growth

                        tree/stand health

                        soil properties

                        stand conditions

Abstract: A field study was carried out in Pseudotsuga menziesii stands in British Columbia, Canada, to investigate the effects on vegetation of glyphosate applications in September 1987 or July 1988, followed by burning in October 1988. Results did only show slight differences between treatments.

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9.
Figueroa, P.F. 1989. Bigleaf maple control: triclopyr thin-line and spot-foliar application treatments using imazapyr, metsulfuron, and glyphosate. Proceedings-of-the-Western-Society-of-Weed-Science (Vol. 42): 104-119.

Keywords:      release treatments

                        chemical release

                        stand conditions

                        economics

Abstract: Field trials were conducted to compare the efficacies of March applications of triclopyr thin-line +or- 1 kg/ha Mor-act or 2,4-D (1:1) with June spot-foliar applications of 0.6 or 1.1 kg/ha imazapyr, 0.170 kg/ha metsulfuron and 6.7 kg/ha glyphosate to control Acer macrophyllum in a Pseudotsuga menziesii plantation. All thin-line treatments gave 80% control 2 years later; complete sanding was hindered by stems growing along the ground. Dilution did not affect control. Spot-application success depended on degree of crown coverage. metsulfuron and glyphosate were not effective, but imazapyr control reached 60-70% 2 years after treatment. Only triclopyr and full coverage imazapyr suppressed A. macrophyllum growth to below the height of P. menziesii. Crown volume was held to pre-treatment levels with metsulfuron and glyphosate but decreased with imazapyr. The two treatment methods tested are potentially cost-effective; triclopyr costs are higher but spot-application carries higher labour costs. Application rates of 2 ml triclopyr/ Msuperscript 2 crown area will give 100% control if all stems are banded; with delivery rates of 59 ml/clump a 45% solution can be used.

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10.
Figueroa, P.F. 1991. Ground applied herbicide methods for red alder control: herbicide efficacy, labor costs, and treatment method efficiency. In Proceedings-of-the-Western-Society-of-Weed-Science,12-14-March-1991. pp. 44: 53-68.

Keywords:      release treatments

                        chemical release

                        economics

                        stand conditions

Abstract: A study was conducted to develop the cost estimates for ground-applied manual control methods in variable density red alder [Alnus rubra] stands and to evaluate the efficacy of the various herbicide formulations for each system. Field trials were initiated in 3 Douglas fir [Pseudotsuga menziesii] plantations located on Weyerhaeuser Company land located in SW Washington. Two 6-year-old plantations had streamside buffer zones remaining from the previous year's operational herbicide spray programme; the 3rd was a 13-year-old plantation which had not been previously treated with herbicides to control A. rubra. The treatments tested were as follows: 50% triclopyr, 45% glyphosate and 10% imazapyr applied to the cut stump surface; low-vol. basal application of 5, 10 and 15% triclopyr and 2 and 4% imazapyr; thin-line application of 50, 75 and 100% triclopyr and 20 and 40% imazapyr; stream-line application of 10, 30 and 50% triclopyr and 4 and 20% imazapyr; hack-and-squirt application with imazapyr applied to 1 cut at 0.25, 0.5 and 0.75 ml and to 2 cuts at 0.25 and 0.5 ml; and capsule injection of 1 or 2 glyphosate capsules. A discussion of the results is presented and total treatment costs are given. It is concluded that ground application treatments have advantages over aerially applied treatments, including being useful for the treatment of areas of public sensitivity and when other environmental risks need to be minimized.

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11.
Figueroa, P.F. 1993. Efficacy and cost of ground-applied herbicide methods for red alder control. Down to Earth 48(1): 6-10.

Keywords:      release treatments

                        chemical release

                        stand conditions

                        growth

                        tree/stand health

Abstract: The effects on red alder [Alnus rubra] mortality, diam. at breast height and height, and any phytotoxic effects to Douglas fir [Pseudotsuga menziesii] of Garlon 4 (triclopyr) at 4 lb/gallon and Chopper EC (imazapyr) at 2 lb, applied by stream line, thin line and low vol. treatments, and of Garlon 3A (triclopyr) at 3 lb, Roundup (glyphosate) at 3 lb and Arsenal (imazapyr) at 4 lb applied by cut stump treatment were evaluated in streamside buffer zones in two 6-year-old P. menziesii plantations in SW Washington. All treatments resulted in good control of A. rubra, but the most cost-effective control was achieved by the stream line application of Garlon 4, followed by low vol. basal or thin line treatments of Garlon 4 and cut stump treatment with 50% Garlon 3, 45% Roundup and 10% Arsenal. Negligible P. menziesii damage was caused by cut stump treatments, but damage occurred with basal-bark treatments although Garlon 4 generally caused less injury than Chopper EC.

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12.
Figueroa, P.F. and V.F. Carrithers. 1993. Bigleaf maple control: thinline basal applications using triclopyr and triclopyr plus picloram. In Proceedings-of-the-Western-Society-of-Weed-Science, 9-11-March-1993. pp. 46: 24-30.

Keywords:      release treatments

                        chemical release

                        stand conditions

                        economics

Abstract: A field trial was conducted at Mt. St. Helens Tree Farm, Cowlitz county, Washington, in 1988-91 to determine the min. threshold level of herbicide needed to control bigleaf maple [Acer macrophyllum] stump sprouts in Douglas fir [Pseudotsuga menziesii]. Garlon (triclopyr) at 0.24-3 lb/gal was applied on 6 Dec. 1990, 6 Feb. 1991 and 11 Apr. 1991, and triclopyr + picloram at 1 + 0.5 lb was applied on 6 Feb. 1991 using thinline applications to the entire circumference of each stem in the bigleaf maple clump. The threshold level of Garlon for <more or =>90% control was found to be between 1.1 and 1.7 ml/msuperscript 2 of crown area. Most treatments produced clumps that appeared to be dead during the 1st year but which resprouted in the 2nd year; it is suggested that such inconsistencies in mortality among treatments are due to the inability to completely band every stem. Economic considerations for herbicide costs are discussed.

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13.
Harrington, T.B., J.C. Tappeiner, II and T.F. Hughes. 1991. Predicting average growth and size distributions of Douglas-fir saplings competing with sprout clumps of tanoak or Pacific madrone. New-Forests 5(2): 109-130.

Keywords:      release treatments

                        manual release

                        growth

                        stand conditions

Abstract: Average growth and size distributions of 3- to 6-year-old (in 1983) Douglas fir (Pseudotsuga menziesii) saplings in three plantations in SW Oregon were studied for 7 years (1983-1989) after thinning of associated sprout clumps of tanoak (Lithocarpus densiflorus) or Pacific madrone (Arbutus menziesii); in some cases shrubs and herbs were also suppressed. Biologically based nonlinear equations explained 66, 90, and 53% of variation in average annual increment of Douglas fir height, diameter-squared, and crown cover, respectively. Equations for annual increment of crown cover of broadleaved and understorey vegetation explained only 10 to 12% of the variation, because these parameters exhibited a high degree of variability. Model simulations demonstrated that, for the same initial levels of cover, tanoak had faster rates of crown cover growth than madrone and also caused greater limitations in Douglas fir growth. Suppression of shrubs and herbs increased growth of Douglas fir only when broadleaved species were absent. Weibull functions adequately described size distributions for Douglas fir in 92% of individual-tree data sets. Regression functions of broadleaved crown cover and average Douglas fir size explained 51, 93, and 24% of variation in the Weibull A, B, and C parameters, respectively. Model simulations with predicted Weibull parameters demonstrated that broadleaved competition caused a positive skewing in size distributions for height and stem diameter of Douglas fir.

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14.
Harrington, T.B., R.G. Wagner, S.R. Radosevich and J.D. Walstad. 1995. Interspecific competition and herbicide injury influence 10-year responses of coastal Douglas-fir and associated vegetation to release treatments. Forest-Ecology-and-Management 76(1/3): 55-67.

Keywords:      release treatments

                        chemical release

                        manual release

                        growth

                        tree/stand health

                        tree physiology

                        stand conditions

Abstract: Responses of competing vegetation and planted Douglas fir (Pseudotsuga menziesii var. menziesii) were studied for 10 years after six herbicide and manual release treatments in the Washington and Oregon Coast Ranges. Studies were installed in six 2- or 3-yr-old plantations, with Douglas fir densities of 988 to 1482 plants/ha at time of planting and 721 to 1282/ha 2 to 3 years late. Research objectives were to quantify regional, long-term responses of vegetation (Douglas fir and non-coniferous species) to various levels of competition, light and soil water availability, and intensity versus importance of factors influencing Douglas fir growth. Three treatments reduced shrub cover relative to the untreated check: triclopyr in year 1, glyphosate in years 1-5, and repeated control (via several herbicide applications) in years 1-10. Reductions in woody cover from glyphosate stimulated increases in herb cover in years 3 and 5, while repeated control reduced herb cover in years 1, 2 and 5. Through year 10, Douglas fir survival (86-99%) varied little among treatments. Visual symptoms of herbicide injury to Douglas fir from triclopyr (45% of trees) and glyphosate (17% of trees) were associated with 0.1-0.2 m reductions in first-year height. After adjusting for tree size, Douglas fir growth in stem basal area 2 years after triclopyr was less than that of the untreated check, suggesting prolonged effects of herbicide injury. Because it sustained low levels of interspecific competition, caused minimal tree injury, and prevented overtopping cover from red alder (Alnus rubra), repeated control was the only treatment in which Douglas fir size (9.8 m height and 21 cm basal diameter in year 10) significantly exceeded (P<less or =>0.02) that of the untreated check (7.8 m height and 12 cm diameter).

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15.
Hedin, I.B. 1994. Mechanical site preparation on salal-dominated sites: five-year results. Forest-Engineering-Research-Institute-of-Canada

Keywords:      site preparation

                        mechanical preparation

                        growth

                        stand conditions

Abstract: Trials began in 1987 on sites on Vancouver Island where salal (Gaultheria shallon) is a competitor to Douglas fir [Pseudotsuga menziesii]. Three equipment types were tested: the Mitsui Miike (an excavator-mounted rock grinding attachment), the TTS Delta disc trencher and an excavator with a ripper tooth and live thumb. All three mechanical site preparation treatments were equally effective at reducing the coverage of salal and other competing vegetation and improving Douglas fir growth performance. On sites where the disc trencher can operate, with gentle slopes and light to moderate slash, it is most cost effective because of greater productivity.

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16.
Hedlin, A.F., J. Weatherston, D.S. Ruth and G.E. Miller. 1983. Chemical lure for male Douglas-fir cone moth, Barbara colfaxiana (Lepidoptera: Olethreutidae). Environmental-Entomology 12(6): 1751-1753.

Keywords:      tree/stand protection

                        stand conditions

Abstract: Field trapping in British Columbia indicated that males of Barbara colfaxiana (Kearfott), the larvae of which feed in the cones of Pseudotsuga menziesii and damage the seeds, were attracted to mixtures of (Z)-9-dodecen-1-ol and (Z)-9-dodecenyl acetate. Most blends of these compounds were attractive to some extent, but blends containing 15 to 50% acetate were the most consistently attractive.

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17.
Helgerson, O.T. 1990b. Response of underplanted Douglas-fir to herbicide injection of sclerophyll hardwoods in southwest Oregon. Western-Journal-of-Applied-Forestry 5(3): 86-89.

Keywords:      nursery operations

                        release treatments

                        chemical release

                        stand conditions

                        tree physiology

                        tree/stand health

                        growth

Abstract: Low-value broadleaf sclerophyll forests in SW Oregon, typically composed of tanoak (Lithocarpus densiflorus), Pacific madrone (Arbutus menziesii) and chinkapin (Castanopsis chrysophylla), may be converted to commercially valuable Douglas fir (Pseudotsuga menziesii) by underplanting. Results are given of studies of container-grown plug and nursery-grown bareroot fir seedlings planted out in March 1983 on plots in which all broadleaf stems had been previously (September 1981) injected with triclopyr amine. Although 60% broadleaf cover was killed by injection, 7 years later ground cover was significantly greater on these treated plots because of sprouting. Seedlings planted beneath treated broadleaf trees experienced greater daytime, but less predawn, moisture stress; plugs survived better than bareroots; and survival of seedlings on treated plots was not significantly better until 2 years after planting. Herbicide injection also resulted in increased height, diameter and volume growth rates of Douglas fir seedlings, and is recommended for the establishment of a conifer stand.

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18.
Henry, C.L., D.W. Cole and R.B. Harrison. 1994. Use of municipal sludge to restore and improve site productivity in forestry: The Pack Forest Sludge Research Program. Forest-Ecology-and-Management 66(1/3): 137-149.

Keywords:      fertilization

                        growth

                        soil properties

                        stand conditions

Abstract: Municipal wastewater residuals - sludge or biosolids - represent a major waste by-product from society that must be managed in responsible ways. Because of its high nutrient and organic matter content, sludge can be beneficially recycled into forest sites for site improvement purposes. This paper reviews the opportunities and problems that have been encountered during 20 yr of research into sludge application in forests, based on data from studies carried out in the Pack Demonstration Forest, Washington, on a variety of sites - including clear-felled, young or mature Douglas fir [Pseudotsuga menziesii] stands, and rights-of-way. Research to date on forest application of sludge has been very encouraging, clearly demonstrating the validity of this management technique. Forest sites typically display benefits in two ways: (1) an immediate growth response by both overstorey and understorey species; (2) a long-term improvement to the productivity of the site. However, for this practice to have broad utility and acceptance, it is critical that the concerns of the regulatory agencies and general public be addressed regarding public health and environmental issues through continued research. These concerns include the fate of trace metals, including movement, uptake and potential phytotoxicity, and passage into wildlife and human food chains, the fate of pathogens, and leaching of nitrates into groundwater systems. Many concerns are a result of misconceptions or misunderstandings of the potential problems involved and require working with these agencies and the general public through education and demonstration programmes.

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19.
Hobbs, S.D. and K.A. Wearstler, Jr. 1985. Effects of cutting sclerophyll brush on sprout development and Douglas-fir growth. Forest-Ecology-and-Management 13(1/2): 69-81.

Keywords:      release treatments

                        manual release

                        stand conditions

                        tree physiology

                        growth

Abstract: In SW Oregon, varying amount of brush were removed from a sclerophyll brushfield dominated by Quercus chrysolepis and Arctostaphylos patula with scattered Pseudotsuga menziesii saplings. Brush removal was accomplished by slashing (cut by chainsaw) near ground level at three intensities: (1) total removal, (2) partial removal, and (3) an untreated control. Sclerophyll brush species responded within 3 weeks of slashing by vigorous sprouting, which was greatest in total brush removal areas where 861 513 sprout stems/ha developed during the first year. Soil water potentials and predawn xylem pressure potentials of Douglas fir were less negative in total removal areas than in partial removal and untreated control areas. Relative growth rates of Douglas fir saplings temporarily increased in total and partial brush removal areas, but were not significantly different from the untreated control 3 yr after treatment. Slashing of sclerophyll brush to release long-suppressed Douglas fir is not recommended because of rapid brush recovery by sprouting.

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20.
Huffman, D.W. and J.C. Tappeiner, II. 1997. Clonal expansion and seedling recruitment of Oregon grape (Berberis nervosa) in Douglas-fir (Pseudotsuga menziesii) forests: comparisons with salal (Gaultheria shallon). Canadian-Journal-of-Forest-Research 27(11): 1788-1793.

Keywords:      thinning

                        stand conditions

Abstract: Seedling regeneration and morphology of Oregon grape (Berberis nervosa) and salal (Gaultheria shallon) were studied in thinned and unthinned Douglas fir (Pseudotsuga menziesii) stands in the central Coast Range, Oregon. Above- and below-ground growth of both species were significantly and negatively correlated with stand density. Oregon grape appears to have less potential for vegetative spread than does salal. It produced two to three times fewer rhizome extensions, and rhizome extensions were only half as long as those of salal. Oregon grape seedlings were common in areas of moss ground cover among patches of the two species. Salal seedlings were restricted to decaying logs. Seedling densities of Oregon grape in thinned stands were more than six times those in unthinned stands. For Oregon grape, understorey establishment is accomplished by seedling establishment and recruitment of new genets. In contrast, salal maintains itself in forest understories primarily through vegetative growth, since its seedling establishment is restricted mainly to decayed wood. Continual recruitment of new aerial stems or ramets enables Oregon grape to maintain a dense cover once it is established in the understorey.

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21.
Huffman, D.W., J.C. Tappeiner, II and J.C. Zasada. 1994. Regeneration of salal (Gaultheria shallon) in the central Coast Range forests of Oregon. Canadian-Journal-of-Botany 72(1): 39-51.

Keywords:      thinning

                        stand conditions

Abstract: Regeneration of salal (Gaultheria shallon) by seedling establishment and vegetative expansion was examined in Douglas fir (Pseudotsuga menziesii) stands that had been thinned, clear felled or undisturbed in the central Coast Range of Oregon. Size and expansion rate of individual clonal fragments were negatively correlated with overstorey stand density (p <less or =>0.039). As overstorey basal area increased from 25 to 75 msuperscript 2/ha, mean annual growth percentage of clone rhizome systems decreased from 23.7 to 0% and mean total rhizome length decreased from 102 to 0.89 m. Interclonal competition in dense clumps of salal apparently caused rhizomes to die and clones to fragment. In these patches, rhizome biomass and density, aerial stem biomass and density, and total biomass of G. shallon were negatively correlated with overstorey density (p <less or =>0.01). In clear fellings, salal clumps had up to 177.7 m rhizome/msuperscript 2 and 346 stems/msuperscript 2, whereas patches under dense overstories had as few as 10.6 m rhizome/msuperscript 2 and 19 stems/msuperscript 2. Aerial stem populations had uneven-age distributions in all overstorey densities. This structure is apparently maintained through annual production of new ramets. Salal seedling establishment rates were significantly affected by study site location, overstorey density, and substrate (p <less or =>0.05). Two-year survival was highest on rotten logs and stumps in thinned stands.

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22.
Hulme, M.A. and G.E. Miller. 1988. Potential for control of Barbara colfaxiana (Kearfott): (Lepidoptera: Olethreutidae) using Trichogramma sp. Colloques de l'INRA (43): 483-488.

Keywords:      tree/stand protection

                        stand conditions

Abstract: The efficacy of Trichogramma minutum for the control of the tortricid Barbara colfaxiana on Pseudotsuga menziesii was assessed. T. minutum was obtained from the tortricid Choristoneura fumiferana in Ontario and reared through over 30 laboratory generations in eggs of the gelechiid Sitotroga cerealella. B. colfaxiana eggs were readily parasitized at 25 degrees C. About 3 million parasitized eggs glued to 100 cards were suspended throughout 19 trees (height 4 to 8 m) in British Columbia. Daytime shade temperatures during the following week peaked at 15-20 degrees C. After 1 day, 6% of the parasitoids had emerged. After 5 days, 54% of sampled parasitized S. cerealella eggs had emergence holes, but eggs on half the cards had been eaten by formicids. Of the B. colfaxiana eggs sampled, 2-4% were parasitized by T. minutum, regardless of whether samples were on the same branch as the cards or on remote branches. It is concluded that T. minutum can parasitize B. colfaxiana in the field and that Trichogramma species which are adapted to B. colfaxiana at temperatures of 15-20 degrees C are needed.


23.
Humphreys, N. 1995. Douglas-fir beetle in British Columbia. In Forest-Pest-Leaflet 14. Pacific-Forestry-Centre,-Canadian-Forest-Service.

Keywords:      tree/stand protection

                        tree/stand health

                        stand conditions

Abstract: Notes are provided on the recognition, detection, biology, injuriousness and control of the scolytid Dendroctonus pseudotsugae on Douglas fir (Pseudotsuga menziesii) (and occasionally western larch (Larix occidentalis)) in British Columbia. The damage caused is described under the headings gallery system; effect on the tree; host susceptibility and attack pattern; association with root disease (including Armillaria ostoyae, Phaeolus schweinitzii and Phellinus weirii); and defoliation (by Choristoneura occidentalis and Orgyia pseudotsugata). Control of D. pseudotsugae is discussed under the headings preventive measures (including log and slash disposal, general logging practices), remedial measures (which include the use of trap trees and pheromones) and brood destruction (by burning and similar measures).

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24.
Karl, M.G. and P.S. Doescher. 1993. Regulating competition on conifer plantations with prescribed cattle grazing. Forest-Science 39(3): 405-418.

Keywords:      release treatments

                        manual release

                        stand conditions

                        tree physiology

                        soil properties

Abstract: On conifer plantations, competitive understorey vegetation often retards growth and establishment of tree seedlings. Livestock grazing is one method of controlling the understorey vegetation and increasing the availability of site resources to tree seedlings. It was hypothesized that prescribed cattle grazing ameliorates water stress of young tree seedlings by reducing root growth of competing understorey species. On a Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa) plantation in SW Oregon planted in 1986, seedling water stress was evaluated using the pressure chamber technique and gravimetric soil water determinations in 1986-89. Root growth of orchardgrass (Dactylis glomerata), the major understorey competing species, was quantified in 1988 and 1989 using the root periscope/mini-rhizotron technique. Seedling water stress levels during spring and summer were similar in cattle-grazed areas and ungrazed areas in 1986 to 1988, but in summer 1989, water stress was reduced significantly in the grazed area. Soil water content was higher in the grazed area in 1989, especially at the 10-20 cm soil depth. End of season (July) orchardgrass root growth in grazed plots was 18% less in 1988 and 15% less in 1989 than root growth in ungrazed plots. It is concluded that repeated cattle grazing of orchardgrass reduced transpirational surface area and root growth sufficiently to increase soil water availability to tree seedlings. Thus, prescribed cattle grazing on conifer plantations can enhance seedling physiological status by acting as a regulator of above- and belowground competition.

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25.
Kelpsas, B.R. 1987. Seasonal impacts of fluroxypyr and triclopyr on conifers and shrubs. Proceedings-of-the-Western-Society-of-Weed-Science (Vol.40): 128-129.

Keywords:      release treatments

                        chemical release

                        tree/stand health

                        stand conditions

Abstract: Release of Pseudotsuga menziesii from Rubus spectabilis and Alnus rubra in a plantation in the Pacific Northwest could be achieved by 1.12 kg fluroxypyr/ha applied in May at the early foliar stage without appreciable long-term injury. P. menziesii tolerated 1.12 kg triclopyr/ha but was severely damaged by 1.12 kg and 2.24 kg fluroxypyr when applied during the dormant season in Mar. Both fluroxypyr and triclopyr were more effective against A. rubra than R. spectabilis. Control of R. spectabilis with triclopyr was marginal.

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26.
Ketchum, J.S., R. Rose and B. Kelpsas. 1999. Weed control in spring and summer after fall application of sulfometuron. Western Journal of Applied Forestry 14:80-85.

Keywords:      site preparation

                        mechanical preparation

                        chemical preparation

                        stand conditions

Abstract: This study tested the residual spring and summer efficacy of sulfometuron after applications in the autumn in second growth Douglas fir (Pseudotsuga menziesii) with red alder (Alnus rubra) and bigleaf maple (Acer macrophyllum) forest sites in the central Coast Range, Oregon, USA, which had been harvested in the summer. Sulfometuron alone (S) and sulfometuron plus imazapyr and glyphosate (SIG) were applied to vegetation on mechanically scarified sites and unscarified sites. The applications were replicated each month throughout autumn 1994. Vegetation cover was assessed in mid-June and mid-August 1995. The SIG treatment gave better control of vegetation than the S treatment, although cover was significantly lower for both herbicide treatments (9% to 54% for summed cover) compared to the control site (64% to 104% for summed cover). On scarified sites, the month of application, early or late autumn, did not significantly influence the efficacy of either treatment. On unscarified sites, however, applications of the SIG treatment later in autumn were less effective than early autumn treatments. Results suggest that autumn applications of sulfometuron are still effective in spring and may eliminate the need to treat sites again in the spring in order to achieve effective weed control.

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27.
Ketchum, J.S., R. Rose and B. Kelpsas. 2000. Comparison of adjuvants used in fall-release herbicide mixtures for forest site preparation. Tree-Planters' Notes 49(3): 66-71.

Keywords:      site preparation

                        chemical preparation

                        release treatments

                        chemical release

                        tree/stand health

                        stand conditions

Abstract: Tank mixes of the herbicides imazapyr and glyphosate were applied at 3 rates with 3 adjuvants (LI-700Reg., Nu-Film-IRReg., Silwet L-77Reg.) over California hazelnut (Corylus cornuta var. californica), vine maple (Acer circinatum), and brackenfern (Pteridium aquilinum var. lanuginosum) on a 2-year-old clearcut of Douglas fir (Pseudotsuga menziesii) in Oregon. The herbicide 2,4-D was applied at 3 rates with 2 adjuvants (HerbimaxReg., Nu-Film-IR) over greenleaf manzanita (Arctostaphylos patula) on a 4-year-old Douglas fir clearcut in Oregon. Tank mixes of imazapyr and glyphosate with LI-700 or Nu-Film-IR were sprayed at 3 rates over 1-year-old seedlings of Douglas fir on 2 sites in Oregon. The herbicide rate strongly influenced the percentage of foliage injured and percentage of stems killed for all herbicide treatments. The adjuvants evaluated did not influence efficacy of herbicide applications on California hazelnut, vine maple, or brackenfern. Herbimax increased visual foliar damage resulting from 2,4-D application on greenleaf manzanita. Douglas fir foliage was damaged by the higher herbicide rates; the damage was greater from Nu-Film-IR than from LI-700.

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28.
Knowe, S.A. and W.I. Stein. 1995. Predicting the effects of site preparation and protection on development of young Douglas-fir plantations. Canadian-Journal-of-Forest-Research 25(9): 1538-1547.

Keywords:      site preparation

                        release treatments

                        tree/stand protection

                        growth

                        tree morphology

                        tree/stand health

                        stand conditions

Abstract: Diameter prediction models based on the Weibull distribution function and stand-table projection models based on changes in relative diameter were developed for 2- to 10-year-old Douglas fir (Pseudotsuga menziesii) plantations in Oregon. Both modelling approaches incorporated the effects of site preparation, animal protection, and competing vegetation. The diameter distribution approach is appropriate when information on initial diameters is not available. The stand-table projection approach may be applied when tree diameters in a plantation are measured two or more growing seasons after planting. At young ages, the stand-table approach provided more accurate representation of observed diameter distributions than the diameter distribution approach. At age 10 the two methods provided comparable diameter distributions. The equations derived for predicting survival, height growth of dominant trees, height-diameter relationships, and the development of woody vegetation over time will facilitate the study and comparison of stand structure and dynamics after various site-preparation and animal protection treatments.

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29.
Knowe, S.A., W.I. Stein and L.J. Shainsky. 1997. Predicting growth response of shrubs to clear-cutting and site preparation in coastal Oregon forests. Canadian-Journal-of-Forest-Research 27(2): 217-226.

Keywords:      planting operations

                        site preparation

                        chemical preparation

                        mechanical preparation

                        prescribed fire

                        stand conditions

Abstract: Cover-projection models were developed based on algebraic difference formulations of an exponential-power function to describe shrub recovery and development patterns following clear cutting, site preparation and Douglas fir (Pseudotsuga menziesii) planting at 4 sites in the Siuslaw National Forest, Oregon. The sites formed part of the Coastal Site Preparation Study initiated in 1980, in which the effects were tested of 6 treatments on shrub growth patterns. Treatments were: none other than scalping a 30-cm spot when each 2-0 seedling was planted (control); spot clearing by cutting to 15 cm height all woody vegetation within a 1.2 m radius of the seedling; spraying with glyphosate (2.52 kg a.e./ha) in early autumn 1980; broadcasting burning slash in midsummer 1980; manually slashing all woody vegetation in June 1980 and broadcast burning later in the summer; and spraying with picloram + 2,4-D (Tordon 101) in May or June 1980 (at 1.49 + 5.97 kg a.e./ha) and broadcast burning in the summer. Results on the development of Douglas fir and associated vegetation to age 10 yr have already been reported for this study (Stein (1995) Research Paper - Pacific Northwest Research Station, USDA Forest Service, No. PNW-RP-473; Knowe & Stein (1995) Canadian Journal of Forest Research 25 (9) 1538-1547). The shrub cover-projection models were developed by incorporating indicator variables into the model rate and shape parameters for the recovery of 3 specific shrubs (salal, Gaultheria shallon; thimbleberry, Rubus parviflorus; and salmonberry, Rubus spectabilis), and all shrubs. For salal, the shape parameter included an adjustment for burning treatments that delayed maximum cover by several years in comparison with unburned treatments. The rate parameter in the thimbleberry model was adjusted for burning treatments; maximum cover occurred about 2 yr earlier in burned than in unburned treatments. Both rate and shape parameters in the salmonberry model were adjusted for burning treatments; delayed established but increased growth rate and less salmonberry cover are characteristic of burned treatments compared with the unburned treatments. The rate and shape parameters in the model for the shrub group included adjustments for burning treatments. Overstorey removal fostered shrub development, whereas site preparation treatments slowed and curtailed it. The final cover-projection models accounted for 68-92% of the total variation in cover, with the adjustments for burning accounting for 1.5-3.3% of the variation. The predicted growth patterns are consistent with trends in site occupancy and published autecological characteristics.

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30.
Leininger, W.C. and S.H. Sharrow. 1987. Seasonal diets of herded sheep grazing Douglas-fir plantations. Journal-of-Range-Management 40(6): 551-555.

Keywords:      release treatments

                        tree/stand health

                        stand conditions

Abstract: The seasonal diets of herded sheep grazing cutover Douglas-fir (Pseudotsuga menziesii) forests in the Coast Range of Oregon were studied during 1981 and 1982. Both 4- to 6-year-old non-grass-seeded and 2-year-old grass-seeded plantations were included. Sheep grazing was monitored in spring, summer and late summer. Forage on offer ranged from 764 to 2459 kg/ha. Vegetational composition of sheep diets varied by year, season and plantation age class. Averaged over the 2 years of grazing, graminoids and forbs were nearly equal, at about 40% each, in sheep diets in older plantations. In contrast, diets of sheep in young grass-seeded plantations averaged 70% graminoids and only 16% forbs. Ferns were a minor component (<2%) of sheep diets in both plantation age classes. Browse averaged 15 and 12% of sheep diets in old and young plantations, respectively. Douglas-fir was most palatable to sheep in spring soon after bud break. It was generally avoided, however, and never comprised more than 3% of sheep diets. Results suggest that sheep can be most effectively used for biological control of unwanted brush species during summer and late summer when differences in relative preference indices for target brush species and Douglas-fir are greatest.

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31.
Lindsey, G.D. and J. Evans. 1983. Evaluation of zinc phosphide for control of pocket gophers on Christmas tree plantations. Tree-Planters' Notes 34(2): 11-14.

Keywords:      tree/stand protection

                        tree/stand health

                        stand conditions

Abstract: In laboratory tests, pocket gophers (Thomomys and Geomys spp.) were offered 5 kinds of treated bait, including 1% Zn phosphide in oats, 0.75% Zn phosphide in fresh carrots, and 0.5% strychnine in rolled oats (3 mixtures). The carrot bait was found to be as effective for killing gophers as the strychnine mixtures. Plots in a 4-yr-old Pseudotsuga menziesii and Pinus monticola plantation in Washington, with occupied T. mazama burrows, were baited with the carrot or one of the strychnine mixtures in Nov. 1981. Both baits produced only a 63% reduction in gopher activity, possibly because of the availability of abundant alternative vegetative food. It was estimated that tree mortality due to root pruning by gophers was >10% on this site. It is recommended that the carrot/Zn sulphide bait be registered for special local needs where safety to wildlife and domestic animals is important.

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32.
Mason, R.R. and B.E. Wickman. 1991. Integrated pest management of the Douglas-fir tussock moth. Forest-Ecology-and-Management 39(1-4): 119-130.

Keywords:      tree/stand protection

                        tree/stand health

                        stand conditions

                        growth

Abstract: The Douglas-fir tussock moth (Orgyia pseudotsugata) is one of the most destructive forest defoliators of Douglas fir (Pseudotsuga menziesii), grand fir (Abies grandis) and white fir (A. concolor) in western North America. An outline is given of current pest-management programmes used in Oregon, which emphasize the annual monitoring of insects in forests with outbreak histories to determine early changes in population numbers and to predict trends. When outbreaks develop, several environmentally safe chemical and microbial insecticides are effective in reducing larval numbers and preventing serious defoliation. Computer models predicting growth loss, tree mortality, and top-kill during outbreaks are available as aids to making management decisions. Silvicultural practices favouring seral nonhost species on high-risk sites may be the best prescription for reducing the effect of tussock moth outbreaks.

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33.
McDonald, P.M. and G.O. Fiddler. 1996. Development of a mixed shrub-tanoak-Douglas-fir community in a treated and untreated condition. Pacific-Southwest-Research-Station, USDA-Forest-Service Research-Paper PSW-RP-225. iv + 16 p.

Keywords:      release treatments

                        manual release

                        chemical release

                        tree/stand health

                        growth

                        tree morphology

                        stand conditions

                        economics

Abstract: On a medium site in northern California, a tanoak (Lithocarpus densiflorus)-mixed shrub community in a Douglas fir plantation was given several treatments (manual release two and three times, a combination chainsaw and cut surface herbicide (Garlon 3A [triclopyr]) treatment, two foliar herbicides (2,4-D or Garlon 4), and a tank mix of the two herbicides) to study its development in both a natural (control) and treated condition. The herbicides were each applied twice. Survival of planted Douglas fir (Pseudotsuga menziesii) seedlings was recorded for 11 years and growth was quantified for 9 years after the last treatment application. In addition to Douglas fir, data are presented individually for the two most abundant species (tanoak and snowbrush, Ceanothus velutinus var. hookeri), for greenleaf manzanita (Arctostaphylos patula), and for the hardwood tree and shrubs combined. At the study's end in 1992, combined vegetation in the control had a mean density of 1800 plants/acre, foliar cover of 23 700 ftsuperscript 2/acre, and height of 11.2 ft. In contrast, combined tree and shrubs in the most effective treatment for controlling them (cut and spray Garlon 3A) had a mean density of 150 plants/acre, foliar cover of 150 ftsuperscript 2/acre and height of 5.9 ft at study end. Because competition for site resources was low, Douglas fir seedlings developed best in this treatment. Mean Douglas fir diameter was 4.6 inches at 12 inches above mean ground line, height averaged more than 21 ft, and mean foliar cover was 39 850 ftsuperscript 2 at the end of the study. The cost was $227 per acre.

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34.
McDonald, P.M. and G.O. Fiddler. 1999. Ecology and development of Douglas-fir seedlings and associated plant species in a Coast Range plantation. Pacific-Southwest-Research-Station, USDA-Forest-Service Research-Paper PSW-RP-243. ii + 18 p.

Keywords:      release treatments

                        manual release

                        chemical release

                        stand conditions

                        growth

                        tree morphology

                        economics

Abstract: On an average site in northern coastal California, USA, a tanoak (Lithocarpus densiflorus)-mixed shrub community was given several treatments (manual release one, two, and three times; a combination chainsaw and cut surface chemical treatment; two foliar chemicals; and a tank mix of the two chemicals) to study its development over an 11-year period (1981-91) in both a broadcast-burned (untreated control) and released (treated) condition. The chemicals were 2,4-D, Garlon [triclopyr] 3A, and Garlon 4, each applied two times. The site had been planted with 2+0 seedlings of Douglas fir (Pseudotsuga menziesii) in 1979. In addition to Douglas-fir , data are presented individually for the four most abundant and well distributed species (tanoak, hairy manzanita (Arctostaphylos columbiana), huckleberries (Vaccinium ovatum and V. parviflorum), and rhododendron (Rhododendron macrophyllum)), and for these plus two more of the tallest and most abundant (but poorly distributed) species (snowbush (Ceanothus velutinus), elderberry (Sambucus mexicana)) combined. In 1991, combined shrubs in the control had a mean density of 4733 plants per acre, foliar cover of 16 800 ft2 per acre, and height of 9.5 feet. In contrast, combined shrubs in one of the most effective treatments for controlling them (2,4-D) had a mean density of 2000 plant per acre, foliar cover of 2600 ft2 per acre and height of 5.5 feet at the end of the study. Here, mean Douglas-fir diameter was 4.0 inches at 12 inches above mean ground line, height averaged 18.7 feet, and mean foliar cover was 34 800 ft2 per acre. The cost (including chemical) was $77 per acre. The biological and economical data in this paper provide the ecosystem manager, wildlife biologist, and fuels manager with knowledge on how to attain plant communities with different density and development potentials, and the cost of creating them.

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35.
McNabb, D.H., K. Baker-Katz and S.D. Tesch. 1993. Machine site preparation improves seedling performance on a high-elevation site in southwest Oregon. Western-Journal-of-Applied-Forestry 8(3): 95-98.

Keywords:      site preparation

                        mechanical preparation

                        tree/stand health

                        stand conditions

                        growth

Abstract: Douglas fir (Pseudotsuga menziesii) seedlings planted on areas receiving one of four site preparation treatments (scarify, scarify/till, soil removal, and soil removal/till) and on unprepared control areas were compared for 5 yr at a high-altitude, nutrient-poor site in the western Siskiyou Mountains. Fifth-year survival of seedlings was at least 85% among machine-prepared plots, compared to 42% on control plots. Cover of competing vegetation remained less than 25% during the period for all machine treatments. In contrast, vegetation cover on control plots was 30% at the time of planting and increased to nearly 75% after 5 yr. Competing vegetation clearly impeded seedling performance. The effects of unusually droughty conditions at the time of planting in 1982 were examined further by interplanting additional seedlings in the soil-removal treatment in 1985. The interplanting was followed by more normal spring precipitation, and seedlings grew better over 5 yr than those planted in 1982. The slow recovery of competing vegetation and generally poor seedling growth on all treatments during both planting years are attributed to low soil fertility.

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36.
Messier, C. and A.K. Mitchell. 1994. Effects of thinning in a 43-year-old Douglas-fir stand on above- and below-ground biomass allocation and leaf structure of understory Gaultheria shallon. Forest-Ecology-and-Management 68(2/3): 263-271.

Keywords:      thinning

                        stand conditions

Abstract: Salal (Gaultheria shallon) was studied in an unthinned and a heavily thinned (two-thirds of basal area removed) 43-yr-old Douglas fir (Pseudotsuga menziesii) plot 6 yr after thinning at Shawnigan Lake on southern Vancouver Island, British Columbia. The increase in both above- and below-ground resources caused by thinning resulted in a smaller fine-root/leaf biomass ratio in the thinned (1.2) than the unthinned (2.0) plot. The balance between the production of fine-roots to acquire limited water and of foliage to acquire limited light is suggested as an explanation for this shift in carbon allocation from fine-root to leaf biomass between the two plots. The responses of G. shallon to thinning are discussed in relation to its role as a competitor for below-ground resources.

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37.
Miller, J.C. and K.J. West. 1987. Efficacy of Bacillus thuringiensis and diflubenzuron on Douglas-fir and oak for gypsy moth control in Oregon. Journal-of-Arboriculture 13(10): 240-242.

Keywords:      tree/stand protection

                        stand conditions

Abstract: In studies at Corvallis, 20 trees of each of Quercus garryana and Douglas fir [Pseudotsuga menziesii] were sprayed from the ground on 6 May 1986 until foliage dripped. Foliage was collected 1 day before spraying and 1-64 days after spraying and bioassayed with 2nd instar larvae of gypsy moth [Lymantria dispar]. Larval mortality was n.s.d. between tree species or between insecticides. Both B. thuringiensis and diflubenzuron caused high larval mortality and were effective for at least 64 days at the doses applied.

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38.
Miller, R.E., D.H. McNabb and J. Hazard. 1989. Predicting Douglas fir growth and response to nitrogen fertilization in western Oregon. Soil-Science-Society-of-America-Journal 53(5): 1552-1560.

Keywords:      fertilization

                        growth

                        soil properties

                        stand conditions