A Model Describing Growth and Development of Longleaf Pine Plantations: Consequences of Observed Stand Structures of Structure of the ModelThis article is part of a larger document. View the larger document here.
As longleaf pine (Pinus palustris Mill.) may currently represent as little as 1/30th of its former acreage, restoration within its former range in the southern coastal plain is active. Although the focus of these new plantings is aimed at ecosystem restoration, knowledge of the growth and development of longleaf plantations is essential to allow land managers to evaluate different management options. Stand development in longleaf plantations differs from development of plantations of other southern pines. Longleaf seedlings exist in a grass-stage for a varying period, and longleaf saplings and poles can often exist in an intermediate or suppressed crown class for long periods. Other southern pines do not exhibit this behavior. The consequence of these characteristics is that smooth, unimodal diameter distributions are inappropriate for characterizing longleaf pine stands. We will use alternative methods to describe the diameter distributions of longleaf pine. Depending upon viewpoint, the proposed model structure could be called a nonparametric diameter distribution model, or a diameter class model where a uniform distribution is not employed within a class. The model can also be implemented as an individual tree model, if the user desires. A neural net approach has proved promising for initially allocating trees to diameter classes for unthinned stands. A whole-stand basal area prediction equation ensures consistency between these components.