Arthropod biomass in winter and the age of longleaf pines

Abstract

The endangered red-cockaded woodpecker ( Picoides borealis) satisfies its nutrient requirements by capturing arthropods from live pine trees. Age of pine stands has been used as a guide for providing suitable habitat for the species, however, little is known about the relationship of arthropods to age of pines. The relationship on longleaf pines ( Pinus palustris) 22–127 years old was examined in winter. Arthropod biomass m −2 on the bole, live limbs and dead limbs was related to tree age, radial growth 6–10 years before sampling and ambient temperature. Arthropod biomass m −2 declined with increasing tree age on the lower, mid- and upper bole; increased with tree age on dead limbs; and increased with tree age on live limbs until 80 years when it declined with increasing age. Slower growing trees had higher arthropod biomass m −2 for a given age than faster growing trees. Total arthropod biomass for the whole tree increased with tree age up to 86 years, when it declined with increasing tree age. However, the older the tree, the greater the arthropod biomass on dead limbs.