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.

HEIGHT GROWTH LOSSES DUE TO ANIMAL FEEDING IN DOUGLAS FIR PLANTATIONS, VANCOUVER ISLAND, B.C.

1964 ◽  
Vol 40 (3) ◽  
pp. 298-307 ◽  
Author(s):  
K. J. Mitchell
Keyword(s):  
Pseudotsuga Menziesii ◽  
East Coast ◽  
Growth Curves ◽  
Tree Height ◽  
Vancouver Island ◽  
Height Growth ◽  
Douglas Fir ◽  
Average Height ◽  
Animal Feeding ◽  
Rotation Age

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantations on the east coast of Vancouver Island, British Columbia, were examined to determine the effect of animal feeding upon height growth.Length of internodes and evidence of past leader damage were recorded and cumulative average height-age growth curves compared for undamaged trees and for trees suffering various intensities of damage.The average reduction in tree height attributable to animal feeding in heavily browsed plantations varied from one-half to two feet over a period of 8 to 10 years. It is unlikely that either tree volume or quality at rotation age would be seriously affected.Exposed trees were browsed more heavily than those protected by vegetation or logging slash.

LASPEYRESIA PSEUDOTSUGAE N. SP. (LEPIDOPTERA: OLETHREUTIDAE), A BARK MINER IN DOUGLAS-FIR

1969 ◽  
Vol 101 (9) ◽  
pp. 955-963 ◽  
Author(s):  
David Evans
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Immature Stages

AbstractA 5-year study of Laspeyresia pseudotsugae n. sp. (Lepidoptera: Olethreutidae) yielded considerable data on the habits, life history and immature stages of this insect, which gained attention because of its conspicuous bark-mine scars on the trunks of young Douglas-fir trees, Pseudotsuga menziesii (Mirbel) Franco. The mines are not deep enough to cause serious damage. L. pseudotsugae has a 1-year life-cycle. Three species of ichneumonid parasites were recovered, and several predators were identified.

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.

Response of young Douglas-fir to urea fertilizer applied on and off snow

1994 ◽  
Vol 70 (3) ◽  
pp. 294-298
Author(s):  
Valin G. Marshall ◽  
Hugh J. Barclay
Keyword(s):  
Key Words ◽  
Pseudotsuga Menziesii ◽  
Vancouver Island ◽  
Douglas Fir ◽  
Similar Response ◽  
Forest Fertilization ◽  
Bare Ground ◽  
Urea Fertilizer ◽  
Absolute Volume

The effects of 200 kg N ha−1 applied as urea fertilizer on 50 cm of snow or on bare ground were studied in an 11-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantation on Vancouver Island. Analysis was done on all trees per plot and on 20 selected dominant trees per plot. Up to 2 years after fertilization, urea significantly increased absolute DBH increments over controls in all trees and the 20 selected trees per plot; response to fertilization on snow was equal to that on bare ground. Between the 3rd and 9th year following fertilization, mean DBH increments were not significantly different for any treatment. Four-year absolute volume increments were 63 and 87% greater than the controls for bare-ground and on-snow applications, respectively. A positive and quantitatively similar response is expected in wetter coastal Douglas-fir stands whether urea is applied on snow or under better conditions during other seasons. Key words: Forest fertilization, season of application, nitrogen, tree response, Pseudotsuga menziesii (Mirb.) Franco

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.

Relationships between temperature and Pacific hake distribution vary across latitude and life-history stage

2020 ◽  
Vol 639 ◽  
pp. 185-197 ◽  
Author(s):  
MJ Malick ◽  
ME Hunsicker ◽  
MA Haltuch ◽  
SL Parker-Stetter ◽  
AM Berger ◽  
...  
Keyword(s):  
Life History ◽  
Environmental Effects ◽  
Environmental Conditions ◽  
Vancouver Island ◽  
Additive Models ◽  
Life History Stage ◽  
Fish Stocks ◽  
Merluccius Productus ◽  
Multiple Dimensions ◽  
Effects Of Temperature

Environmental conditions can have spatially complex effects on the dynamics of marine fish stocks that change across life-history stages. Yet the potential for non-stationary environmental effects across multiple dimensions, e.g. space and ontogeny, are rarely considered. In this study, we examined the evidence for spatial and ontogenetic non-stationary temperature effects on Pacific hake Merluccius productus biomass along the west coast of North America. Specifically, we used Bayesian additive models to estimate the effects of temperature on Pacific hake biomass distribution and whether the effects change across space or life-history stage. We found latitudinal differences in the effects of temperature on mature Pacific hake distribution (i.e. age 3 and older); warmer than average subsurface temperatures were associated with higher biomass north of Vancouver Island, but lower biomass offshore of Washington and southern Vancouver Island. In contrast, immature Pacific hake distribution (i.e. age 2) was better explained by a nonlinear temperature effect; cooler than average temperatures were associated with higher biomass coastwide. Together, our results suggest that Pacific hake distribution is driven by interactions between age composition and environmental conditions and highlight the importance of accounting for varying environmental effects across multiple dimensions.

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