Next Article in Journal
How Biotic Differentiation of Human Impacted Nutrient Poor Deciduous Forests Can Affect the Preservation Status of Mountain Forest Vegetation
Previous Article in Journal
Effects of Drought and Rewetting on Growth and Gas Exchange of Minor European Broadleaved Tree Species
Article Menu
Issue 10 (October) cover image

Export Article

Open AccessArticle
Forests 2016, 7(10), 238; doi:10.3390/f7100238

Individual-Tree Competition Indices and Improved Compatibility with Stand-Level Estimates of Stem Density and Long-Term Production

1
Rayonier Inc., University of Georgia, NC State University, P.O. Box 1679, Yulee, FL 32041, USA
2
School of Forest Resources, University of Maine, Orono, ME 04469-5755, USA
*
Author to whom correspondence should be addressed.
Academic Editor: Timothy A. Martin
Received: 1 July 2016 / Revised: 27 September 2016 / Accepted: 30 September 2016 / Published: 15 October 2016
View Full-Text   |   Download PDF [2407 KB, uploaded 15 October 2016]   |  

Abstract

When explaining the dynamics of individual trees, the incorporation of size and distance of neighboring trees into a model can improve the prediction of growth and mortality. Several methods have been proposed to define the number of competing trees based on variable zone radii and the principles of angle count sampling. The task of measuring position-dependent competition indices appears to be ideally suited for permanent sample plots and long-term studies of growth and yield (production), where the marginal effort of remeasurement is concentrated on measuring size attributes of survivor trees and the occasional distance of a new sample tree. The proposed competition index is based on point sampling with a variable basal area factor (BAFV) that is partially derived from the Spurr (1962) competition index. Point sampling is a fast, easy, and inexpensive methodology for selecting the number of competing trees, and the new BAFV methodology proved to be very efficient for estimating growth. With the selection of an appropriate basal area factor, it is possible to reduce the number of subject trees and competition trees in the sample, and eliminate the need for edge correction methods. Although the index value assigned to the subject tree using the BAFV is biased, an appropriate correction is presented and discussed. The average competition index obtained from using the corrected value for the subject tree and the BAFV for the competing trees equals the stand level estimate of basal area. View Full-Text
Keywords: angle count or point sampling; permanent sample plots; additive estimates angle count or point sampling; permanent sample plots; additive estimates
Figures

Figure 1

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. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

McTague, J.P.; Weiskittel, A.R. Individual-Tree Competition Indices and Improved Compatibility with Stand-Level Estimates of Stem Density and Long-Term Production. Forests 2016, 7, 238.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Forests EISSN 1999-4907 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top