Self-referencing site index equations for unmanaged loblolly and slash pine plantations in east TexasThis article is part of a larger document. View the larger document here.
The Schnute growth function was used in this study to model site index for unmanaged or low-intensity managed loblolly pine (Pinus taeda, L.) and slash pine (Pinus elliottii, Engelm.) plantations in east Texas. The algebraic difference approach was used to derive an anamorphic base-age invariant site function that was fit as a fixed base-age anamorphic site function (base age = 25 years). The dataset was comprised of 1,135 and 502 serially correlated height-age observations of loblolly and slash pine, respectively, which were collected over a 20-year-period as a part of the East Texas Pine Plantation Research Project (ETPPRP). The new site functions represent an improvement over earlier site functions for east Texas, especially for slash pine, primarily because the new function accounted for serial correlation in the data. The new site index equations apply to unmanaged or low intensity managed loblolly and slash pine plantations in east Texas ranging in age from 5 to 40 years.