Advances in Agriculture and Agricultural Sciences

Advances in Agriculture and Agricultural Sciences ISSN 2381-3911 Vol. 4 (1), pp. 001-005, January, 2018. © International Scholars Journals

Full Length Research Paper

A weighted relative density model applied to loblolly pine (Pinus taeda L.) stands

John M. Lhotka¹ and Edward F. Loewenstein²

¹University of Kentucky, Department of Forestry, 105 T. P. Cooper Building, Lexington, KY 40546-0073.

²Auburn University, School of Forestry and Wildlife Sciences Building, Auburn University, Alabama 36849-5418.

Accepted 09 April, 2017

Abstract

We present a weighted, individual-tree relative density approach whose reference conditions have the same distribution of crown areas and species as a subject stand. An initial evaluation of the method’s efficacy was performed within an even-aged loblolly pine (Pinus taeda L.) plantation. Species-specific reference density equations were developed using plot data and existing crown width equations. Diameter growth prediction was evaluated using data from a thinned 20-year-old plantation. Regression analysis was used to related annual diameter increment and the approach’s density indices. The predictive ability of the presented method was compared to existing approaches such as Stand Density Index (SDI) and Crown Competition Factor (CCF). Results suggest the weighted, individual-tree approach predicts diameter increment as well as traditional indices. These findings suggest an individual tree approach may not be necessary within an even-aged loblolly pine plantation with a narrow diameter range.

Key words: relative density, size-density, Pinus taeda L., loblolly pine.