COMMUNITY AND ECOSYSTEM ECOLOGY Responses of Arthropods to Large-Scale Manipulations of Dead Wood in Loblolly Pine Stands of the Southeastern United States

Large-scale experimentalmanipulations of deadwood are needed to better understand its importance to animal communities in managed forests. In this experiment, we compared the abundance, species richness, diversity, and composition of arthropods in 9.3-ha plots in which either (1) all coarse woody debris was removed, (2) a large number of logs were added, (3) a large number of snags were added, or (4) no coarse woody debris was added or removed. The target taxa were ground-dwelling arthropods, sampled by pitfall traps, and saproxylic beetles (i.e., dependent on dead wood), sampled by ßight intercept traps and emergence traps. There were no differences in total ground-dwelling arthropod abundance, richness, diversity, or composition among treatments. Only the results for groundbeetles (Carabidae),whichweremore species richanddiverse in log inputplots, supportedourprediction that ground-dwelling arthropodswouldbeneÞt fromadditionsofdeadwood. There were also no differences in saproxylic beetle abundance, richness, diversity, or composition among treatments. The Þndings from this study are encouraging in that arthropods seem less sensitive than expected to manipulations of dead wood in managed pine forests of the southeastern United States. Based on our results, we cannot recommend inputting large amounts of dead wood for conservation purposes, given the expense of such measures. However, the persistence of saproxylic beetles requires that an adequate amount of dead wood is available in the landscape, and we recommend that dead wood be retained whenever possible in managed pine forests.