Download or read book Diameter Growth Equations for Douglas fir and Grand Fir in the Western Willamette Valley of Oregon written by Abdel Azim Zumrawi and published by . This book was released on 1993 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Equations for predicting diameter growth are an essential component of single-tree growth and yield models (Munro 1974). Diameter growth predictions are used to characterize individual-tree development and to project the growth of stand basal area and volume. Both diameter growth and basal area growth have been used as the dependent variable in modeling the development of a tree's diameter (Holdaway 1984, Ritchie and Hann 1985, Wykoff 1986, Wensel et al. 1987, Dolph 1988). The choice of which dependent variable to use has usually been suggested by the data, including the behavior of the residuals and the goodness-of-fit of the resulting equations. Ritchie and Hann (1985) developed nonlinear basal-area growth equations for Douglas-fir (Pseudotsuga menziesii) and grand fir (Abies grandis). It was intended that the equations would be used to predict individual- tree diameter growth in the western Willamette Valley version of ORGANON (Hann et al. 1992). However, Hann and Larsen (1991) found that using a basal-area growth equation to predict diameter growth could result in erratic and unreasonable predictions of diameter growth for trees with small diameters. Therefore, the objective of the present study was to develop diameter growth equations for Douglas-fir and grand fir in the western Willamette Valley of Oregon by using the equation form of Hann and Larsen (1991)."--Introduction.
Download or read book A Compendium of Forest Growth and Yield Simulators for the Pacific Coast States written by Martin W. Ritchie and published by . This book was released on 1999 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reanalysis of the SMC ORGANON Equations for Diameter growth Rate Height growth Rate and Mortality Rate of Douglas fir written by David W. Hann and published by . This book was released on 2006 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using existing data from untreated research plots, we developed equations for predicting 5-yr diameter-growth rate (delta D5), 5-yr height-growth rate (delta H5), and 5-yr mortality rate (PM5) for Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] in the coastal region of the Pacific Northwest. These equations are revisions of the equations constructed in 1995-1997 for the Stand Management Cooperatives (SMC) version of the ORGANON growth-and-yield model, and they have been developed with substantially larger and more comprehensive data sets than were available in 1995-1997. The new delta D5 and delta H5 equations were validated with an independent data set. The PM5 equation was evaluated by comparing 100-yr predictions of Reinekes (1933) stand density index to behavior previously reported from measurements taken on long-term researchplots. The new delta D5, delta H5, and PM5 equations appear to be considerably superior in predictive ability and behavior to the original equations. The effects of the new equations on stand-level predictions were evaluated by comparing the maximum mean annual increments (MAI) in total stem volume (ft3) and associated rotation ages (RA) predicted from the original SMC-ORGANON model to predictions from the revised SMC-ORGANON model. This analysis was done by making 100-yr projections using 170 plots in young stands from the SMC data sets. Some of the ending values for average crown ratio (CR) after 100 yr of projection were near 15%, however, and predictions of basal area (BA) for some of these stands peaked and then declined over stand age. Substituting the HCB equation published by Hann and Hanus in 2004 for predicting crown recession (delta HCB5) eliminated the problem with BA peaking over stand age and resulted in somewhat larger average ending CRs. The 100-yr projections were then made again with the 2004 HCB equation of Hann and Hanus. On average, the revised model reduced RA by 2.1 yr (or 4.3%) and maximum MAI by 55.7 ft3/ac/yr (18.9%).
Download or read book Continuous Cover Forestry written by Klaus von Gadow and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: The large-scale application of new silvicultural systems has become a political reality in many parts of the world. This involves a gradual transformation of traditional silvicultural practice towards Continuous Cover Forestry, also known as near-natural forest management, favouring mixed uneven-aged stands, site-adapted tree species and selective harvesting. Selective harvesting systems have a long tradition. Specific CCF-related resource assessment, forecasting and sustainable harvest control techniques have been developed, but details about their use are not widely known. The objective of this volume is to present state-of-the-art research results and techniques relating to CCF management with an emphasis on systems engineering and modelling. Using a very simple classification based on the development of timber volume over age or time we may distinguish two types of sustainable forest management systems. Rotation forest management (RFM) systems, characterized by standard silvicultural treatments and repetitive cycles of clearfelling followed by planting; and continuous cover forestry (CCF) systems which are characterized by selective harvesting and natural regeneration, resulting in uneven-aged structures and frequently also in multi-species forests. The distinction is usually the result of decisions relating to the cost of timber harvesting, simplicity of management, or various intangible benefits. The oldest and most perfect examples of CCF systems are the so called plenter selection forests found in France, Switzerland, Slowenia and Germany. Today, CCF systems are encountered in various regions of Europe, North America and in some tropical and sub-tropical forests of South Africa, Asia and South America.
Download or read book Sustainable Forestry written by and published by CABI. This book was released on 2007 with total page 553 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the context of forest sustainability, this book presents the issues related to both global climate change and conservation of biodiversity. It highlights four methodologies and shows how they contribute in overcoming the ecological challenges facing our world. The practical experience presented can be applied to the implementation of successful sustainable forestry policies.
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 Research Contribution written by and published by . This book was released on 1993 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hearing on Chairman s Draft H R The Community Protection and Hazardous Fuels Reduction Act of 1999 to Safeguard Communities Lives and Property from Catastrophic Wildfire by Authorizing Contracts to Reduce Hazardous Fuels Buildups on Forested Federal Lands in Wildland urban Interface Areas While Also Using Such Contracts to Undertake Forest Management Projects to Protect Noncommodity Resources written by United States. Congress. House. Committee on Resources. Subcommittee on Forests and Forest Health and published by . This book was released on 1999 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 106 1 Hearing Hearing On Chairman s Draft H R The Community Protection And Hazardous Fuels Reduction Act Of 1999 Etc Serial No 106 3 February 9 1999 written by and published by . This book was released on 1999 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research Paper Forest Research Laboratory Oregon State University written by Oregon State University. Forest Research Laboratory and published by . This book was released on 1979 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Predicting Height to Crown Base for Undamaged and Damaged Trees in Southwest Oregon written by Mark L. Hanus and published by . This book was released on 2000 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Equations for predicting height to crown base are presented for tree species from southwest Oregon. Equations for undamaged and damaged trees were estimated with weighted nonlinear regression techniques. The effects of specific damaging agents on the height to crown base were explored, and damage correction factors were estimated. The damage correction factors can be used to correct the predicted crown ratio for specific damaging agents and their severity in samples where damage is noted. These equations are being incorporated into the new southwest Oregon version of ORGANON (ORegon Growth ANalysis and projectiON), a model for predicting the growth of individual trees in forest stands. The equations extend the past model to older stands and stands with a heavier component of hardwood tree species.
Download or read book General Technical Report PNW GTR written by and published by . This book was released on 2002 with total page 1074 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research Paper written by Oregon State University. Forest Research Laboratory and published by . This book was released on 1965 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Equations for Predicting the Largest Crown Width of Stand grown Trees in Western Oregon written by David W. Hann and published by . This book was released on 1997 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Largest crown width (LCW) equations for stand-grown trees were developed for 14 tree species found in western Oregon. The equations are used in the growth-and-yield model ORGANON and in the stand-visualization program VIZ4ST. They were constructed such that LCW equals the maximum crown width of open-grown trees when the crown ratio is equal to one. Tree measurements needed for the equations are diameter at breast height (in.), total tree height (ft), and crown length (ft).
Download or read book Biennial Bibliography written by Oregon State University. Forest Research Laboratory and published by . This book was released on 1992 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Production and Costs of Cut to length Thinning written by Loren D. Kellogg and published by . This book was released on 2004 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using multiple linear regression equations with indicator variables, we compared both harvesting and forwarding cycle times among treatments. We conducted detailed time studies on a harvester and a forwarder and used these data to develop two regression equations to predict delay-free harvest cycle times and delay-free forwarding cycle times. Delay information was gathered from both shift-level and detailed time studies. Total costs for each treatment were obtained by combining costs for harvesting, forwarding, and moving equipment in and out for the entire operation.
Download or read book Canadian Journal of Forest Research written by and published by . This book was released on 2004 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt:
