Abstract
A generalized sigmoid growth function was used in this study to model site index (SI) for unmanaged or lowintensity managed loblolly pine (
Pinus taeda, L.) and slash pine (
Pinus elliottii, Engelm.) plantations in east Texas. Schnute's growth function was fit to 11,367 and 5,040 height-age observations of loblolly and slash pine, respectively. These data were collected over a 20-year period from unmanaged pine plantations located across the east Texas region as a part of the East Texas Pine Plantation Research Project (ETPPRP). The fit model was used to derive SI equations (25-year index age). The SI equations apply to unmanaged or low-intensity managed loblolly and slash pine plantations in east Texas ranging in age from 5 to 40 years. They can also serve as a baseline for SI estimation of intensely managed pine plantations.
Parent Publication
Citation
Coble, Dean W.; Lee, Young-Jin. 2006. Use of a generalized sigmoid growth function to predict site index for unmanaged loblolly and slash pine plantations in East Texas. Gen. Tech. Rep. SRS-92. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. pp. 291-295