Stand conditions and tree characteristics affect quality of longleaf pine for red-cockaded woodpecker cavity trees

Abstract

We measured resin flow of longleaf ( Pinus palustris Mill.) pines in red-cockaded woodpecker ( Picoides borealis Vieillot) clusters in the Angelina National Forest in Texas, and the Apalachicola National Forest in Florida. Sample trees were categorized as active cavity trees, inactive cavity trees and control trees. Sample trees were further categorized by stand position as either edge or interior trees. Longleaf cavity trees in Texas and Florida had similar resin flow characteristics. Active cavity trees on forest edges had the highest resin flow, whereas active cavity trees in forest interiors had the lowest. Trees experiencing both low and high levels of red-cockaded woodpecker activity and competition from other trees had low resin flow, whereas intermediate stress typically resulted in high resin flow. Results from this study indicate that the best active red-cockaded woodpecker cavity trees, from a resin flow perspective, are on or near forest edges. This may explain the woodpecker's observed tendency to excavate new cavities near edges even when interior basal area has been reduced and midstory has been controlled. Our results suggest that pines managed as potential cavity trees should be experiencing minimal competition, and that a mosaic of patches in red-cockaded woodpecker habitat may be preferable to more uniform conditions.