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International Journal of Forestry Research
Volume 2010 (2010), Article ID 212068, 8 pages
http://dx.doi.org/10.1155/2010/212068
Research Article

Rapid Assessment of Relative Density in Mixed-Species Stands of the Northeastern United States

Department of Natural Resources and the Environment, University of New Hampshire, 310 Nesmith Hall, Durham, NH 03824, USA

Received 22 June 2009; Accepted 1 December 2009

Academic Editor: Terry L. Sharik

Copyright © 2010 M. J. Ducey and R. A. Knapp. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Basal area has shortcomings as a measure of stand density, but it is often preferred for operational assessments because it is easy to measure. Previous work has demonstrated that an additive version of Reineke's stand density index can be estimated by a simple tree count using a modified horizontal point sampling technique. We show that this technique can be extended further to estimate a mixed-species density measure that has been developed for complex stands in the northeastern United States, using wood specific gravity to harmonize the density contributions of different species. The sampling technique provides design-unbiased estimates of stand density from a weighted tree count, where the weights depend on specific gravity but not on diameter. Rounding the specific gravity values for different species in the calculation of estimates introduces a trivial amount of bias but streamlines the procedure for rapid use in the field.