Results Of Shelterwood Harvesting Of Douglas Fir In The Cascades Of Western Oregon Classic Reprint

Author : Richard L. Williamson
Publisher : Forgotten Books
ISBN 13 : 9780331846522
Total Pages : 644 pages
Book Rating : 4.27/5 ( download)

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Download or read book Results of Shelterwood Harvesting of Douglas-Fir in the Cascades of Western Oregon (Classic Reprint) written by Richard L. Williamson and published by Forgotten Books. This book was released on 2017-11-24 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Results of Shelterwood Harvesting of Douglas-Fir in the Cascades of Western Oregon U. S. Forest Service experience has shown that clearcutting Douglas-fir in the Pacific Northwest does not always result in successful regeneration, either natural or artificial. Where regeneration has failed, this has been due to such causes as temperature extremes and drought. Failures, primarily at higher elevations in the Oregon Cascades, led the Forest Service to try shelter wood harvesting, beginning in 1962, as a possible alternative to clearcutting. I surveyed these initial shelterwood stands in summer 1970 with two main objectives. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

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ISBN 13 :
Total Pages : pages
Book Rating : 4.85/5 ( download)

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Download or read book Results of Shelterwood Harvesting of Douglas-fir in the Cascades of Western Oregon written by and published by . This book was released on 1973 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : Susan Willits
Publisher :
ISBN 13 :
Total Pages : 40 pages
Book Rating : 4.9X/5 ( download)

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Download or read book Lumber Recovery of Douglas-fir from the Coast and Cascade Ranges of Oregon and Washington written by Susan Willits and published by . This book was released on 1988 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the results of lumber recovery studies at four sawmills in western Oregon and western Washington; two dimension mills, one grade mill, and one timber mill were included. Results from individual mills are reported and discussed. The four mills were also combined to approximate "average" conversion of logs to lumber for the region. Recovery information is presented by diameter and log grade for lumber volume, lumber grade, and lumber and log value.

Author : Eric K. Zenner
Publisher :
ISBN 13 :
Total Pages : 116 pages
Book Rating : 4.72/5 ( download)

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Download or read book Effects of Residual Trees on Growth of Young to Mature Douglas- Fir and Western Hemlock in the Western Central Oregon Cascades written by Eric K. Zenner and published by . This book was released on 1995 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this study was to assess how growth of young to mature Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sar.) in mixed stands was influenced by the presence of residual trees. Fourteen paired plots with and without residual trees were examined in a retrospective study on the Willamette National Forest, Oregon. Growth was analyzed at the stand level, and at the individual tree level, contrasting growth behavior of Douglas-fir and western hemlock. Stands were generally highly stocked with relative densities between 0.38 and 1.05 and age ranged between 55 and 121 years. Results indicate that both understory and residual tree densities had a major influence on average tree size and growth and yield of the young cohort. At the stand level, residual trees and high understory densities reduced volume, basal area, and the mean squared diameter of the young cohort, while understory mortality increased. The influence of residual tree density on total understory and Douglas-fir volume and basal area was best fit by a negative logarithmic function. After accounting for understory density effects, the decrease of understory volume and basal area per individual residual tree decreased with increasing residual tree density. With 5 to 50 residual trees/ha, total understory volume reduction was 22 and 45%, respectively, averaging 2.4 and 1.5% per residual tree, respectively. In mixed stands, Douglas-fir volume and basal area declined more rapidly than the volume and basal area of the entire young cohort, when residual tree density exceeded 15 trees/ha. This was probably due to the relative shade-intolerance of Douglas-fir. Douglas-fir volume and basal area on southerly aspects was more than double the values on northerly aspects. Examination of quadratic mean diameters and radial growth rates by crown class revealed that the average size and growth rates of dominant Douglas-fir were not reduced by residual trees. However, the number and basal area of understory trees, particularly dominant and codominant Douglas-fir, declined with increasing residual tree densities. Understory volume was highest in stands that had lowest understory densities. High understory stocking levels were associated with reduced growth and high mortality rates of the young cohort, suggesting stands were undergoing self-thinning. At the individual tree level, basal area growth and diameter growth of trees increased with increasing size and dominance. The marginal effect of residual trees declined with increasing numbers of residual trees per hectare. No residual tree effects on heights of dominant Douglas-fir was found, perhaps because the few dominant Douglas-firs may have been located sufficiently far from residual trees to minimize interaction. Due to high stocking levels in the young cohort, results from this study only apply to stands with relative densities above 0.38. In addition, leave-trees in managed stands may be younger, smaller, and may have different growth rates from residual trees in this study, thus affecting the young cohort differently. Finally, due to the observational nature of this study, cause-and-effect relationships cannot be established. However, since understory volume was highest in stands with low understory densities, understory density management may reduce growth.

Author : Dawn M. Egeland
Publisher :
ISBN 13 :
Total Pages : 222 pages
Book Rating : 4.72/5 ( download)

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Download or read book Vegetation-environmental Relationships on Two Clearcuts on the Western Slopes of the Oregon Cascades written by Dawn M. Egeland and published by . This book was released on 1985 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Douglas-fir and western hemlock growth and stocking were examined on two neighboring clear-cut watersheds in the Western Cascades of Oregon and related to the intensity of burning and logging disturbance, habitat type, soil type, aspect and the influence of percent cover of both invading Ceanothus species and residual Acer circinatum. The nitrogen content of the surface soil, both total and mineralizable nitrogen, and current and year old Douglas-fir foliar nitrogen contents as percent dry weight were determined. Total nitrogen content was determined by micro-kjeldahl techniques. Mineralizable nitrogen was obtained through anaerobic incubation at 40 C for seven days. Douglas-fir establishment and growth were not limited on severely burned or compacted sites. A strong preference for unburned sites was shown by western hemlock, however. Appreciable Douglas-fir stocking, basal diameters, basal areas and relative densities were supported by Rhma/Gash, Acci/Gash and Cola habitat types. Cola communities also contained the greatest western hemlock stocking and basal area values. Soil type influenced Douglas-fir but not western hemlock. Largest Douglas-fir basal diameters, basal areas and relative densities were found on lateritic soil types. Both Douglas-fir and western hemlock stocking were favored on northerly exposures, though the basal diameters of Douglas-fir were maximized on level and westerly aspects. The percent cover of snowbrush (Ceanothus velutinus), redstem ceanothus (C. sanguineus), deerbrush (C. integerrimus) and vine maple (Acer circinatum) was also examined in relation to site factors. Cover values of all Ceanothus species were highest on disturbed and! or burned sites. For the most part, the three Ceanothus species had varying preferences in terms of habitat type, soil type and aspect expressed as degrees of cover. Percent vine maple cover was only influenced by burning and habitat type, preferring sites undisturbed by burning and Rhma/Gash, Acci/Gash and Acci/Bene communities in which it was also an important component before logging. Nultiple regressions indicated that no site factor, shrub cover or nitrogen variable accounted for more than sixteen percent of the total explained variation in conifer growth or stocking. Site factors could explain the most variation. greater Douglas-fir basal diameters occurred on plots with snowbrush cover, while the presenee of redstem ceanothus was associated with lower Douglas-fir basal diameters, basal areas and relative densities. The presence of Ceanothus species was generally not associated with increased soil or foliar nitrogen content, though Douglas-fir year old needles showed slightly higher mean values on sites with redstem ceanothus. Plots containing vine maple, however, contained greater quantities of mineralizable nitrogen. Nitrogen data indicates that though total soil nitrogen levels appear adequate for Douglas-fir nutrition, mineralizable and foliar nitrogen may be limiting at least during the growing season. While partially ameliorated, results suggest that the effects from harvesting and slash burning have yet to subside, though factors including habitat type, soil type and aspect are becoming increasingly- important in determining the distribution of shrub cover as well as the growth and establishment of Douglas-fir and western hemlock.

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ISBN 13 :
Total Pages : 322 pages
Book Rating : 4.86/5 ( download)

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Download or read book Management of wildlife and fish habitats in forests of western Oregon and Washington written by and published by . This book was released on 1985 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : Christopher D. Dowling
Publisher :
ISBN 13 :
Total Pages : 258 pages
Book Rating : 4.73/5 ( download)

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Download or read book Comparing Structure and Development of Douglas-fir Old-growth, Plantations, and Young Natural Forests in Western Oregon written by Christopher D. Dowling and published by . This book was released on 2003 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ages, diameter growth, density, tree size, and species were studied in old-growth, plantation, and young natural Douglas-fir stands in three areas in western Oregon: the western and eastern Coast Range and the western Cascades. The purpose was to compare the development of these three stand types and to determine whether plantations and young natural stands would develop old-growth structures and characteristics. The Douglas-fir age ranges in plantations (8 to 15 yr) were much narrower and than the ranges of tree ages found in the young natural (21 to 102 yr) and in the old-growth stands (300 to 354 yr). This wide range of tree ages, along with diameter growth rates and tree and stand structural characteristics, supported the hypothesis that old-growth developed at low initial stand densities. These low initial stand densities, probably the result of prolonged stand establishment, likely enabled height and crown size advantages among old and younger trees. Dominant and large codominant trees maintained live crown ratios and sustained diameter growth resulting in large stable trees indicated by low height-to-diameter ratios. The mean diameters of the dominant trees in the old-growth and the dominant trees in the young natural stands were not significantly different at age 40 and 100, indicating the young natural stands appear to be growing at the same rates as the old-growth in its first 100 years. The mean dominant diameters in the plantations and old-growth at age 40 and 100 were significantly different, indicating the plantations are growing and developing differently than young natural and old-growth forests. Plantations had grown rapidly for the first 20 to 30 years, and computer simulation indicated that a significant rapid decline in radial growth would occur between ages 30 and 55. Simulations also indicate that during this period, the mean diameters of the dominant plantation trees would fall below those of the old-growth in two of the three stands by age 85. Pre-commercial thinning 20 to 25 years ago in the plantations has helped sustain high early growth rates for a longer period of time than would have occurred if thinning had not been performed. Additional thinning in the future is likely needed to maintain rapid current rates. When simulated to age 250 both the young natural stands and the plantations maintained higher densities of smaller diameter trees than the old-growth stands. This simulation result indicates the possible inability of these stands to self-thin to the densities found in old-growth stands without some sort of density-reducing disturbance. The broad range of tree ages in the old-growth stands suggests that stand disturbances are a normal part of old-growth development on these sites. Five different plantation thinning options were also simulated to age 250, including additional options with thinning of understory trees and ingrowth. The projections indicate that when the plantations are left unthinned they would generally develop trees with small live crowns and mean diameters but still produce stable dominant overstory trees (low H:D ratios). Shade tolerant understory trees and ingrowth, such as western hemlock, are a key part of old-growth development. These trees may reduce the rate of growth and alter crown structure of the overstory trees over extended periods of time (200+ years). Additional thinning, possibly in multiple entries, in both the overstory and understory may be necessary for dense plantations to develop the tree size heterogeneity found in local old-growth forests. I also demonstrated a methodology to determine site-specific management targets or goals for creating old-growth structure from plantations. This was performed using past and current forest structure and composition information within a local landscape scale of 500 to 1000 acres, typical of the public land checkerboard ownership pattern. Stand types making up the historical landscape are identified and described retrospectively using historical and current aerial photographs and digital orthophotos, cruise records, previous studies, and sample plots of standing and harvested forests. The degree of detail provided through this methodology will likely help forest managers to define complex late-successional characteristics of stands and landscapes. My results indicate that stand and project area-specific definitions of old-growth and clearly defined goals for young stand management will facilitate development of old forest characteristics.

Author : Anna Lowenhaupt Tsing
Publisher : Princeton University Press
ISBN 13 : 0691220557
Total Pages : 348 pages
Book Rating : 4.50/5 ( download)

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Download or read book The Mushroom at the End of the World written by Anna Lowenhaupt Tsing and published by Princeton University Press. This book was released on 2021-06-08 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A tale of diversity within our damaged landscapes, The Mushroom at the End of the World follows one of the strangest commodity chains of our times to explore the unexpected corners of capitalism. Here, we witness the varied and peculiar worlds of matsutake commerce: the worlds of Japanese gourmets, capitalist traders, Hmong jungle fighters, industrial forests, Yi Chinese goat herders, Finnish nature guides, and more. These companions also lead us into fungal ecologies and forest histories to better understand the promise of cohabitation in a time of massive human destruction."--Publisher's description.

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ISBN 13 :
Total Pages : 306 pages
Book Rating : 4.48/5 ( download)

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Download or read book CWE written by and published by . This book was released on 1998 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : Brenda C. McComb
Publisher : CRC Press
ISBN 13 : 1420007637
Total Pages : 338 pages
Book Rating : 4.33/5 ( download)

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Download or read book Wildlife Habitat Management written by Brenda C. McComb and published by CRC Press. This book was released on 2007-06-20 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, conflicts between ecological conservation and economic growth forced a reassessment of the motivations and goals of wildlife and forestry management. Focus shifted from game and commodity management to biodiversity conservation and ecological forestry. Previously separate fields such as forestry, biology, botany, and zoology merged