Extending Southwest Oregon's Douglas-fir Dominant Height Growth Equation to Older Ages
Extending Southwest Oregon's Douglas-fir Dominant Height Growth Equation to Older Ages

Author: David W. Hann

Publisher:

Published: 1998

Total Pages: 24

ISBN-13:

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Hann and Scrivani (1987) developed dominant height growth equations for Douglas- fir in southwest Oregon using stem analysis data sets with an upper age of approximately 125 years at breast height. The objective of this study was to determine whether these equations could be extrapolated for ages of 250 years or more. Data for the evaluation came from stem analysis of 60 dominant trees located in 30 "older" stands. Intensive data screening indicated that 53 of these trees exhibited signs of reduced height growth during their first 100 years of development due to competition from non-tree vegetation, hardwood tree species, and possibly other conifers in non-even-aged stands. Analysis of the remaining seven site-quality trees indicated that the existing dominant height growth equation for Douglas-fir could be extrapolated to breast height ages of up to 245 years without loss of accuracy or precision.

Forest Growth and Yield Modeling
Forest Growth and Yield Modeling

Author: Aaron R. Weiskittel

Publisher: John Wiley & Sons

Published: 2011-08-22

Total Pages: 431

ISBN-13: 0470665009

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Forest Growth and Yield Modeling synthesizes current scientific literature and provides insights in how models are constructed. Giving suggestions for future developments, and outlining keys for successful implementation of models the book provides a thorough and up-to-date, single source reference for students, researchers and practitioners requiring a current digest of research and methods in the field. The book describes current modelling approaches for predicting forest growth and yield and explores the components that comprise the various modelling approaches. It provides the reader with the tools for evaluating and calibrating growth and yield models and outlines the steps necessary for developing a forest growth and yield model. Single source reference providing an evaluation and synthesis of current scientific literature Detailed descriptions of example models Covers statistical techniques used in forest model construction Accessible, reader-friendly style

Predicting Height for Undamaged and Damaged Trees in Southwest Oregon
Predicting Height for Undamaged and Damaged Trees in Southwest Oregon

Author: Mark L. Hanus

Publisher:

Published: 1999

Total Pages: 28

ISBN-13:

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Equations for predicting tree height as a function of diameter outside bark at breast height are presented for various tree species common to southwest Oregon. Data for damaged and undamaged trees were analyzed with weighted nonlinear regression techniques. The effects of specific damaging agents and their severity on the height-diameter relationship were explored. Damage correction multipliers were estimated, then used to correct predicted height where damage was noted. Because the relationship between height and diameter changes with the competitive position of the tree in a stand, alternative equations are presented that include the average height and diameter of the 40 largest-diameter undamaged conifer trees per acre. Foresters can use these "height-diameter" equations to reduce the time-consuming task of measuring heights of every tree in an inventory, stand exam, or timber cruise. They can also use these equations to estimate the change in height as diameter changes. These equations will be incorporated into the new southwest Oregon version of ORGANON, which extends the model to older stands and stands with a heavier component of hardwood species.

Nonlinear Regression Modeling
Nonlinear Regression Modeling

Author: David A. Ratkowsky

Publisher:

Published: 1983

Total Pages: 296

ISBN-13:

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Introduction to regression models; Assessing nonlinearity in nonlinear regression models; Yield-density models; Sigmoidal growth models; Asymptotic regression model; Some miscellaneous models; Comparing parameter estimates from more than one data set; Obtaining good initial parameter estimates; Summary: towatd a unified approach to nonlinear regression modeling.

Wildlife Habitats in Managed Forests
Wildlife Habitats in Managed Forests

Author: Jack Ward Thomas

Publisher:

Published: 1979

Total Pages: 528

ISBN-13:

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That is what this book is about. It is a framework for planning, in which habitat is the key to managing wildlife and making forest managers accountable for their actions. This book is based on the collective knowledge of one group of resource professionals and their understanding about how wildlife relate to forest habitats. And it provides a longoverdue system for considering the impacts of changes in forest structure on all resident wildlife.

Fundamentals of Tree Ring Research
Fundamentals of Tree Ring Research

Author: James H. Speer

Publisher: University of Arizona Press

Published: 2010

Total Pages: 360

ISBN-13: 0816526850

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This comprehensive text addresses all of the subjects that a reader who is new to the field will need to know and will be a welcome reference for practitioners at all levels. It includes a history of the discipline, biological and ecological background, principles of the field, basic scientific information on the structure and growth of trees, the complete range of dendrochronology methods, and a full description of each of the relevant subdisciplines.