Topographic features associated with loblolly pine decline in central Alabama.

Abstract: Loblolly pine (Pinus taeda L.) decline has been present in upland sites of central Alabama since the 1960s. Symptoms of loblolly pine decline (fine root deterioration, short chlorotic needles, sparse crowns, reduced radial growth) begin in the 30–40 year age class, resulting in premature death at ages 35–50. Loblolly pine decline occurs on sandy, well-drained soils and is associated with Leptographium spp., as well as with root-feeding bark beetles and weevils. The present article discusses the results of a comparison of biological factors associated with pine decline and topographical features, using the analysis of tree health at the Talladega National Forest and Westervelt (formerly Gulf State Paper) Company in central Alabama. Results of this study suggest that an ecological pattern of tree decline and mortality exists. Loblolly stands were more prone to develop symptoms at sites with increased slope and south/southwest orientation. This report indicates that the dominant determinants, or predictors, of loblolly decline are identifiable topographical features. [Copyright &y& Elsevier]