A new approach to modeling stand-level dynamics based on informed random walks: Influence of bandwidth and sample size.

Abstract

Abstract

A new stand-level dynamics model based on observed stand growth trajectories is presented. This stand-level dynamics model uses the trajectories of observed plots through Reineke's quadratic mean diameter-density space to predict the change in quadratic mean diameter, ingrowth and mortality over time. The model uses the collection of observed trajectories as a probability distribution that is used to guide an informed random walk. An imputation model is used to select k nearest neighbors (bandwidth) which are then used to build joint kernel distributions. From these kernel distributions, m random samples (sample intensity) are averaged to predict the change in quadratic mean diameter, ingrowth and mortality. All levels of k tested (10, 20, 30) performed well as long as sampling intensity was above 1. Variability in predictions was reduced at sampling intensities above 1, but no significant differences were visible among sampling intensities 5 and above.

Department

Natural Resources and the Environment; New Hampshire EPSCoR

Publication Date

7-2013

Journal Title

Forestry

Publisher

Oxford Journals

Digital Object Identifier (DOI)

10.1093/forestry/cpt008

Document Type

Article

Rights

© Institute of Chartered Foresters, 2013. All rights reserved.

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