scholarly journals Temperature regulation of bud-burst phenology within and among years in a young Douglas-fir (Pseudotsuga menziesii) plantation in western Washington, USA

2006 ◽  
Vol 26 (4) ◽  
pp. 421-430 ◽  
Author(s):  
J. D. Bailey ◽  
C. A. Harrington
Keyword(s):  
Pseudotsuga Menziesii ◽  
Temperature Regulation ◽  
Douglas Fir ◽  
Bud Burst ◽  
Western Washington

Twenty-Eight Years of Thinning at Several Intensities in a High-Site Douglas-Fir Stand in Western Washington

1990 ◽  
Vol 5 (2) ◽  
pp. 37-40 ◽  
Author(s):  
Kevin L. O'Hara
Keyword(s):  
Pseudotsuga Menziesii ◽  
Rapid Growth ◽  
Basal Area ◽  
Douglas Fir ◽  
Growth Potential ◽  
Control Treatment ◽  
High Site ◽  
Western Washington

Abstract A 28-year thinning study in a dense, natural, high-site coastal Douglas-fir (Pseudotsuga menziesii) stand compared three thinning treatments and an unthinned control. Gross, net, and total recoverable periodic cubic volume increments from the control treatment were not significantly different from the highest yielding thinned treatment. An increasing reserve basal area thinning treatment was the least severe thinning treatment and produced the highest gross, net, and total recoverable periodic increments of the thinning treatments. Commercial thinnings of dense or fully stocked plantations of Douglas-fir may produce similar results: vigorous stands with rapid growth potential. West. J. Appl. For. 5(2):37-40, April 1990.

scholarly journals Log and Lumber Grades and Value from a Douglas-Fir Stand 20 Years after Thinning and Biosolids Fertilization

2004 ◽  
Vol 19 (1) ◽  
pp. 34-41
Author(s):  
David Briggs ◽  
Edie Sonne ◽  
Eric Turnblom ◽  
Gero Becker
Keyword(s):  
Interest Rate ◽  
Willingness To Pay ◽  
Interest Rates ◽  
Pseudotsuga Menziesii ◽  
Untreated Control ◽  
Treatment Effects ◽  
Douglas Fir ◽  
Yield And Quality ◽  
Western Washington ◽  
Stand Yield

Abstract Three replications of four treatments: biosolids fertilization, thinning, thinning plus biosolids fertilization, and untreated control were established in 1977 in a dense, low site, 55-yr-old Douglas-fir (Pseudotsuga menziesii) stand in western Washington. In 1998, 12 trees from each treatment were harvested, bucked into logs, and sawn into visually graded lumber. Taking into account effects of treatments on stand yield and log grades, biosolid fertilization only, thinning only, and thinning combined with biosolids increased log value/ac by $1,142 (19%), $3,642 (62%), and $9,069 (155%), respectively, over the untreated control. When treatment effects were viewed in terms of changes in lumber yield and quality, per acre gains over the control were $2,107 (26%), $5,683 (70%), and $10,708 (132%), respectively. Willingness to pay analysis indicates that if the landowner intends to manage the stand to a rotation of about 75 yr, each of the treatments, and especially the combination of thinning and applying biosolids, appears to be financially attractive at both 5 and 9% interest rates. However, if the rotation had been set at 55 yr, only the thinning/biosolids combination at 5% interest rate would entice management to delay immediate harvest. West. J. Appl. For. 19(1):34–41.

Yield Comparison of Three Douglas-Fir Plantations on Former Farmland in Western Washington

1990 ◽  
Vol 5 (4) ◽  
pp. 123-126
Author(s):  
Marshall D. Murray ◽  
Constance A. Harrington
Keyword(s):  
Pseudotsuga Menziesii ◽  
Nutrient Availability ◽  
Site Index ◽  
Douglas Fir ◽  
Annual Increment ◽  
Volume Yield ◽  
Western Washington ◽  
Natural Stands ◽  
Mean Annual Increment ◽  
Enhanced Yield

Abstract Yields of three Douglas-fir (Pseudotsuga menziesii) plantations on former farmland were substantially greater than DFSIM yields for the plantations based on site index estimates from adjacent natural stands. Volume yield per acre of trees 1.6 in. dbh and larger was 40 to 57% greater in the actual plantations than in the simulations. For trees 7.6 in. dbh and larger, volume yield of the actual plantations was 85 to 151% greater than the simulated yields. Mean annual increment of the actual plantations was 56 to 69% greater than the simulated values. In addition, top height was greater in two of the plantations than predicted. Running a second set of simulations with site index estimates based on plantation trees reduced the discrepancy in yields but still resulted in substantial underpredictions. Some possible reasons for enhanced yield of the plantations on former farmland are greater site uniformity, reduced vegetative competition, and increased nutrient availability. West. J. Appl. For. 5(4):00-00, October 1990.

The Life History and Habits of a Midge, Contarinia oregonensis Foote (Diptera: Cecidomyiidae) in Douglas-fir Cones

1961 ◽  
Vol 93 (11) ◽  
pp. 952-967 ◽  
Author(s):  
A. F. Hedlin
Keyword(s):  
Life History ◽  
Pseudotsuga Menziesii ◽  
Single Species ◽  
Vancouver Island ◽  
Douglas Fir ◽  
Number Of Species ◽  
Western Washington

A midge, Contarinia oregonensis, is one of a number of species of insects which causc seed losses in Douglas fir, Pseudotsuga menziesii (Mirb.) Franco. In recent years it has been reported causing more damage than any other single species of Douglas-fir cone insect in western Washington (Johnson and Heikkkenen. 1958). This has been the situation on Vancouver Island also.The species bas described by Foote (1956) from specimens taken in Oregon in 1916.

Multi-decadal establishment for single-cohort Douglas-fir forests

2014 ◽  
Vol 44 (9) ◽  
pp. 1068-1078 ◽  
Author(s):  
James A. Freund ◽  
Jerry F. Franklin ◽  
Andrew J. Larson ◽  
James A. Lutz
Keyword(s):  
Pseudotsuga Menziesii ◽  
Temporal Patterns ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Old Growth ◽  
Old Growth Forests ◽  
Western Washington ◽  
Century Development ◽  
Single Cohort

The rate at which trees regenerate following stand-replacing wildfire is an important but poorly understood process in the multi-century development of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) forests. Temporal patterns of Douglas-fir establishment reconstructed from old-growth forests (>450 year) have generated contradictory models of either rapid (<25 year) or prolonged (>100 year) periods of establishment, while patterns of tree establishment in mid-aged (100 to 350 year) forests remains largely unknown. To determine temporal patterns of Douglas-fir establishment following stand-replacing fire, increment cores were obtained from 1455 trees in 18 mature and early old-growth forests in western Washington and northwestern Oregon, USA. Each of the stands showed continuous regeneration of Douglas-fir for many decades following initiating fire. The establishment period averaged 60 years (range: 32–99 years). These results contrast both with the view of rapid (one- to two-decade) regeneration of Douglas-fir promoted in the early forestry literature and with reports of establishment periods exceeding 100 years in older (>400 year) Douglas-fir–western hemlock stands. These results have important implications for management designed to create and promote early-seral forest characteristics.

Polyamines conjuguées et différenciation florale chez le sapin de Douglas (Pseudotsuga menziesii (Mirb.) Franco)

1998 ◽  
Vol 76 (5) ◽  
pp. 782-790
Author(s):  
EL-Hassania Daoudi ◽  
Marc Bonnet-Masimbert
Keyword(s):  
Pseudotsuga Menziesii ◽  
Floral Induction ◽  
Calcium Nitrate ◽  
Douglas Fir ◽  
Bud Burst ◽  
Floral Initiation ◽  
Vegetative Buds ◽  
Conjugated Polyamines ◽  
The Status ◽  
Flowering Initiation

To characterize as early as possible the status of flowering differentiation in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), the variation of bound or conjugated polyamines is studied in the shoots of young plants (6 years old) during the period covering flowering initiation (between 30 and 75 days after bud burst). These compounds are also quantified in sexual and vegetative buds. The quantitative effects of treatments susceptible to stimulate the flowering (application of gibberellins and (or) calcium nitrate) on the level of conjugated polyamines are investigated in the shoots. The combination of gibberellins to calcium nitrate application strongly increases the flowering. Conjugated polyamines are particularly abundant in sexual buds and in the shoots of flowering plants. Sexual buds are also characterized by a ratio of conjugated putrescine to conjugated spermidine about four to six times higher than in vegetative buds. The accumulation of conjugated polyamines in the shoots accompanies bud sexualization, which suggests that conjugated polyamines may constitute potential markers of floral initiation in Douglas-fir.Key words: floral induction, flowering marker, conjugated polyamines, Douglas-fir.

scholarly journals Low Cost Improvement of Coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) By Application of The Breeding Seed Orchard Approach in Denmark

2005 ◽  
Vol 54 (1-6) ◽  
pp. 218-227 ◽  
Author(s):  
J. K. Hansen ◽  
H. Wellendorf ◽  
E. D. Kjær
Keyword(s):  
Pseudotsuga Menziesii ◽  
Low Cost ◽  
Seed Orchard ◽  
Douglas Fir ◽  
Bud Burst ◽  
Effective Population ◽  
Narrow Sense Heritability ◽  
Seed Orchards ◽  
Seedling Seed Orchard ◽  
Stem Straightness

Abstract An evaluation of a seedling seed orchard in Denmark of Coastal Douglas-fir showed variation between open pollinated families in their susceptibility to windthrow, height and diameter growth, stem straightness, number of forks at age 10 and bud burst at age 9. Individual narrow-sense heritability was 0.63 for bud burst, 0.40 for height and diameter, respectively, 0.48 for stem straightness, 0.20 for number of forks and 0.17 for windthrow susceptibility. Fast growing families were characterised by late bud burst, and poorer stem straightness. The approach of using seedling seed orchards in Denmark is discussed in relation to genetic gains, genetic diversity and risk of inbreeding. Predicted gains concerning a reduction of windthrow susceptibility were poor due to low genetic variability. In multi-trait selection scenarios aiming to improve growth, stem straightness and reducing windthrow susceptibility, the approach of using seedling seed orchards demonstrated that it might be possible to obtain gains in height above 5% combined with significant improvements of stem straightness while retaining an effective population size above 50.

scholarly journals Pathogenicity and Virulence of Pythium Species Obtained from Forest Nursery Soils on Douglas-Fir Seedlings

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 744-748 ◽  
Author(s):  
Jerry E. Weiland ◽  
Bryan R. Beck ◽  
Anne Davis
Keyword(s):  
Pseudotsuga Menziesii ◽  
Seedling Survival ◽  
The United States ◽  
Douglas Fir ◽  
Tree Seedlings ◽  
Pythium Species ◽  
Forest Nursery ◽  
Damping Off ◽  
Greenhouse Study ◽  
Forest Nurseries

Pythium species are common soilborne oomycetes that occur in forest nursery soils throughout the United States. Numerous species have been described from nursery soils. However, with the exception of P. aphanidermatum, P. irregulare, P. sylvaticum, and P. ultimum, little is known about the potential for other Pythium species found in nursery soils to cause damping-off of tree seedlings. A greenhouse study was conducted to evaluate the pathogenicity and virulence of 44 Pythium isolates representing 16 species that were originally recovered from soil at three forest nurseries in Washington and Oregon. Seeds of Douglas-fir (Pseudotsuga menziesii) were planted into soil infested with each of the isolates. Seedling survival, the number of surviving seedlings with necrotic root lesions, and taproot length were evaluated 4 weeks later. Responses of Douglas-fir to inoculation varied significantly depending on Pythium species and isolate. Eight species (P. dissotocum, P. irregulare, P. aff. macrosporum, P. mamillatum, P. aff. oopapillum, P. rostratifingens, P. sylvaticum, and P. ultimum var. ultimum) significantly reduced the number of surviving seedlings compared to the noninoculated treatment. However, all Pythium species caused a greater percentage of seedlings to develop root lesions (total mean 40%) than was observed from noninoculated seedlings (17%). Taproot length varied little among Pythium treatments and was not a useful character for evaluating pathogenicity. Results confirm the ability of P. irregulare, P. mamillatum, and P. ultimum var. ultimum to cause damping-off of Douglas-fir seedlings, and are indicative that other species such as P. dissotocum, P. aff. macrosporum, P. aff. oopapillum, P. rostratifingens, and P. sylvaticum may also be responsible for seedling loss.

Cylindrocarpon and Fusarium root colonization of Douglas-fir seedlings from British Columbia reforestation sites

1998 ◽  
Vol 28 (8) ◽  
pp. 1198-1206 ◽  
Author(s):  
Paige E Axelrood ◽  
William K Chapman ◽  
Keith A Seifert ◽  
David B Trotter ◽  
Gwen Shrimpton
Keyword(s):  
British Columbia ◽  
Pseudotsuga Menziesii ◽  
Root Colonization ◽  
Linear Trend ◽  
Poor Performance ◽  
Douglas Fir ◽  
Root Infection ◽  
Significant Linear Trend ◽  
Conifer Seedlings ◽  
Cylindrocarpon Destructans

Poor performance of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantations established in 1987 has occurred in southwestern British Columbia. Affected sites were planted with 1-year-old container stock that exhibited some root dieback in the nursery. A study was initiated in 1991 to assess Cylindrocarpon and Fusarium root infection in planted and naturally regenerating (natural) Douglas-fir seedlings from seven affected plantations. Percentages of seedlings harboring Cylindrocarpon spp.and percent root colonization were significantly greater for planted seedlings compared with natural seedlings. A significant linear trend in Cylindrocarpon root colonization was observed for planted seedlings with colonization levels being highest for roots closest to the remnants of the root plug and decreasing at distances greater than 10cm from that region. This trend in Cylindrocarpon colonization was not observed for natural seedlings. Cylindrocarpon destructans (Zins.) Scholten var. destructans and C.cylindroides Wollenw. var. cylindroides were the only species isolated from planted and natural conifer seedlings. For most sites, percentage of seedlings harboring Fusarium spp.and percent Fusarium root colonization were less than for Cylindrocarpon. Recovery of Fusarium spp.from seedlings and root colonization levels were not significantly different for planted and natural seedlings from all sites.

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