FOREST PRODUCTIVITY PREDICTS INVERTEBRATE BIOMASS AND OVENBIRD (SEIURUS AUROCAPILLUS) REPRODUCTION IN APPALACHIAN LANDSCAPES

Abstract

Forest-floor detrital food webs are sustained by annual inputs of leaf fall. However, it is unknown whether this bottom-up effect extends to vertebrates feeding on the detrital food web. We hypothesized that reproductive success of Ovenbirds (Seiurus aurocapillus L.) is a function of acroinvertebrate biomass within the detrital food web, and that both macroinvertebrate biomass and Ovenbird reproduction can be predicted from forest productivity (measured by site index). We found that across diverse topography within two physiographic provinces of the central Appalachian Mountains macroinvertebrate biomass is correlated with forest site index. Furthermore, Ovenbird reproduction is a significant, positive function of both site index and macroinvertebrate biomass. We conclude that bottom-up effects of forest productivity propagate though the detrital food web to secondary/tertiary vertebrate predators. Thus site productivity is an effective tool for predicting landscape-scale variation in avian productivity and the strength of bottom-up effects within the forest food web.