Download or read book Thinning Shock and Response to Fertilizer Less than Expected in Young Douglas Fir Stand at Wind River Experimental Forest written by and published by DIANE Publishing. This book was released on with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thinning Shock and Response to Fertilizer Less Than Expected in Young Douglas fir Stand at Wind River Experimental Forest written by Dean S. DeBell and published by . This book was released on 2002 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thinning Stock and Response to Fertilizer Less Than Expected in Young Douglas fir Stand at Wind River Experimental Forest written by Dean S. DeBell and published by . This book was released on 2002 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thinning Shock and Response to Fertilizer Less Than Expected in Young Douglas fir Stand at Wind River Experimental Forest written by Dean S. DeBell and published by . This book was released on 2002 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research Paper PNW written by and published by . This book was released on 1978 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 2003 with total page 880 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Forest of Time written by Margaret J. Herring and published by . This book was released on 2007 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Wind River Experimental Forest has been called the cradle of forestry in the Pacific Northwest. Located in the Gifford Pinchot National Forest in southwest Washington, the forest is a nexus of groundbreaking discoveries in forest genetics and ecology, and is one of more than seventyfive Forest Service landscapes across the U.S. devoted to forest and range research. Forest of Time follows one hundred years of forest science at Wind River, as social and scientific changes transformed the twentieth century and the Pacific Northwest forest itself. The Forest Service began research at Wind River in 1908 to learn the secrets of the giant Douglas fir. During the course of the century, generations of scientists studied the forest from different angles, and their conclusions changed through time. Initially, Wind River scientists saw the region in need of protec tion from fire and careless logging. They saw scorched, cutover land that required replanting. Later they saw the forest in need of improvement, needing to be freed from pests and unprofitable s pecies and replaced with thrifty, fastgrowing plantations. Wind River soon became a laboratory where foresters from around the world came to learn how to grow the best possible lumber in the shortest amount of time. As plantations replaced natural forest stands, scientists came to Wind River to explore the complexity of oldgrowth forest ecosystems. And today, Wind River is the center of a twentyfirst century exploration of forest canopies and the global connec tion between forests and atmos phere. In Forest of Time, Margaret Herring and Sarah Greene show readers how science grows and changes in unexpec ted ways, much like a forest through time. It is a story of discovery and blindness, of opportunities taken and missed, in a forest dedicated to longterm research.
Download or read book Annual Report written by Oregon State University. Swiss Needle Cast Cooperative and published by . This book was released on 2004 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Silviculture and Ecology of Western U S Forests written by John C. Tappeiner and published by . This book was released on 2007 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: "An essential reference for forest managers, policy makers, forest scientists, and students, this authoritative volume provides a basis for silviculture practices and contemporary management of western forests."--BOOK JACKET.
Download or read book Equations for Predicting Height to crown base 5 year Diameter growth Rate 5 year Height growth Rate 5 year Mortality Rate and Maximum Size density Trajectory for Douglas fir and Western Hemlock in the Coastal Region of the Pacific Northwest written by David W. Hann and published by . This book was released on 2003 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using existing permanent research plot data, we developed equations for predicting height-to-crown-base (HCB), 5-yr diametergrowth rate (delta D), 5-yr height-growth rate (delta H), 5-yr mortality rate (PM), and the maximum size-density trajectory for Douglasfir and western hemlock in the coastal region of the Pacific Northwest. With the exception of the HCB equation, the equations developed for predicting trees from untreated plots agreed in predictive behavior with previously published equations for the study area. The HCB equation predicted shorter HCB (and therefore longer crown lengths [CL]) than previously published equations for the study area. Western hemlock showed no response to fertilization. Modifiers for fertilization response were incorporated into the final equations for predicting delta D, delta H, and PM in Douglas-fir. All three modifiers for Douglas-fir predicted an increase in growth and mortality rates with the amount of nitrogen applied and a decrease with number of years since fertilization, with most of the fertilization effect gone within 15 yr of application. For the delta D and delta H modifiers, the size of the increase varied by the site index (SI) of the plot, with plots of lower site quality showing greater increases. For delta D, fertilization response did not appear to vary by plot density, tree size, or tree position within the plot. Modifiers for thinning response were incorporated into the final equations for predicting tree delta D for both species and delta H for Douglas-fir. For both species, the delta D thinning-effects modifier predicted an increased growth rate with the proportion of the BA removed and a decrease with years since thinning; most of the thinning effect was gone within 10 yr. For Douglas-fir, the delta H thinning-effects modifier predicted a reduced growth rate immediately after thinning, with the size of the reduction increasing with the intensity of thinning. Most of the reduction was gone by about 10 yr. For Douglas-fir, the combined effect on delta D and delta H of applying both thinning and fertilization could be adequately characterized by the product of the thinning modifier and the fertilization modifier. The percent increase in predicted growth rate due to a combined treatment thus was greater than the sum of the percent increases for each treatment alone. Analysis of the maximum size-density trajectory data strongly suggests that plots of neither species approach a single maximum stand density index value (SDI) as they develop. The potential yield for a given site therefore depends, not only on its SI, but also on its maximum SDI. Fertilization does not appear to affect the intercept of the maximum size-density line for Douglas-fir. The strengths and weaknesses of the existing data sets and the modeling and analytical approaches tested during development of these equations are presented to aid future modelers, and alternative modeling approaches are explored.
Download or read book Response to Commercial Thinning in a 110 year Old Douglas fir Stand written by Richard L. Williamson and published by . This book was released on 1982 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thinning Effects on Stand and Tree Growth written by Pablo Romero Castaño and published by . This book was released on 2014 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: The search for the stand density that optimizes growth and hence generates the maximum amount of wood is one of the philosopher's stone in modern forestry. Since scientific methods were applied to forestry, numerous generations of foresters have studied the relations between stocking density and growth, obtaining diverse results and structuring acquired knowledge into different principles that continue to be debated by supporters and detractors. Three main principles are: 1) any reduction in stand density entails a decreasing in the growing capacity, 2) growth is constant for a range of stand densities and, 3) progressive reductions in stand density increase growth up to an optimum, after which growth starts decreasing. Thinning is the traditional tool that foresters use to manage stand density. Consequently, most of growth-growing stock relations are based on data from thinning experiments. In addition to the potential effects of thinning on growth of residual trees, the erratic behavior of periodic annual increment routinely found in field studies may be contributed by measurement errors, imputation inaccuracies, variation in initial conditions, imprecise treatment implementation, irregular mortality, or variation in definition of density and stocking. These sources of variation in response to thinning lead to different results and different interpretations of conformity to the principles listed above. The Black Rock Unit of the George T. Gerlinger Experimental Forest in Oregon holds one of the largest and oldest Douglas-fir thinning experiments with the native region of this species. The characteristics of the stand, particularly the age when treatments were carried out and the initial dimensions of the trees, broaden our perspective to the on results from other studies in other areas and in younger stands of both Douglas-fir and other species. Reductions in stand density generally lead to a change in the expected growth of the stand, most typically a reduction in growth more or less commensurate with the reduction in stand density, as further controlled by the initial diameter, height, and crown length of the residual trees. The direct effect of thinning is that portion of the growth response that is systematically related to the type, intensity, and timing of the thinning and that is not explained by the relationship of growth to conventional stand, tree, and site predictor variables in unthinned stands. Accurate forecasting of tree and stand growth after thinning therefore requires quantification of the direct effects of thinning and its change over time since thinning. In an effort to isolate the direct effect of thinning treatments at the stand and tree level, from effects of conventional stand, tree, and site variables, regression techniques were applied to data from a set of thinned and unthinned stands. After an initial period of no response, limited response, or even "shock", thinning increased stand growth inversely proportional to the intensity of treatment (if stands were compared at the same initial conditions). The overall direct effect of thinning was consequently an initial decrease relative to the growth rate of an unthinned stand with the same initial conditions, but then an increase growth after several years. Direct effects at the stand level were the aggregate result of direct effects of thinning on the constituent trees. These tree-level direct effects were more complicated than has previously been assumed in growth models. Trees of different diameter classes (correlated with crown classes) differed in their direct response to thinning. In general, thinning had little direct effect on growth patterns in the largest diameter class (largest 28%), increased the growth performance in mid-sized trees (next largest 22% by diameter), and reduced initially the average growth of smallest trees (smallest 19% by diameter). However, most diameter classes under most thinning intensities recovered quickly after a few years and direct thinning effects led to greater growth that expected for the same initial conditions in unthinned stands. The intensity of thinning increased this positive direct response among all size classes. These results help to understand the factors that control growth in Douglas-fir stands. Likewise, quantification of direct growth effects attributable to thinning add to our knowledge base on tree and stand-level responses to thinning. In regard to the stated growth-growing stock principles, the Black Rock thinning trials seemed to support the principle that stand growth declines in direct proportion to thinning intensity. The eventual growth increase stimulated by the direct thinning effect did not compensate for the reduced growing stock imposed by thinning. Furthermore, little evidence was found for uniform growth across a wide range in initial stand density. Finally, analyses of individual trees and percentiles of the diameter distribution corresponding roughly to crown classes demonstrated that the direct effect of thinning within a stand is not uniform across tree size, implying that stand-level multipliers for the direct thinning effect might gainfully be replaced by a tree-level function of relative tree size as well as thinning intensity and time since thinning.
Download or read book Initial Thinning Effects in 70 to 150 year old Douglas fir western Oregon and Washington written by Richard L. Williamson and published by . This book was released on 1971 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Volume Growth and Response to Thinning Anf Fertilizing of Douglas fir Stands in Southwestern Oregon written by Richard E. Miller and published by . This book was released on 1988 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Response of Douglas fir Seedlings to Nitrogen Sulfur and Phosphorus Fertilizers written by M. A. Radwan and published by . This book was released on 1985 with total page 710 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Response of Young Douglas fir to 16 Years of Intensive Thinning written by John C. Tappeiner and published by . This book was released on 1982 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: A 20-year-old Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] stand in the Oregon Coast Range was thinned from about 1,700 to about 350 trees/ac. Subsequent thinnings, under eight different regimes, occurred at ages 23, 27, 30, and 32. Average net periodic cubic-volume growth was strongly influenced by thinning regime, varying from about 220 ft /ac/yr (heavy thinning age 30) to over 550 ft /ac/yr (controls age 23). The results indicate that young Douglas-fir on productive sites (site index 160 to 170 ft at 100 years) are extremely adaptable and will respond to frequent thinnings of various intensities. Three representative treatments (after thinning at age 32) and the controls were projected and optimized with dynamic programming for two financial analyses. Adjusting rotation or commercial thinning can compensate for lack of early stand management or heavy early thinning.
Download or read book Thinning Response in 110 year old Douglas fir written by Richard L. Williamson and published by . This book was released on 1966 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: