Comparison of Coleoptera emergent from various decay classes of downed coarse woody debris in Great Smoky Mountains National Park, USA

Coleoptera species composition and succession in downed woody debris habitats are poorly known in eastern North America. A photoeclector emergence chamber was used to concentrate Coleoptera that emerged from various decay classes of fine and coarse woody debris (FWD and CWD, respectively) collected in primary and secondary forest sites in Great Smoky Mountains National Park, Tennessee, USA. A total of 5673 adult beetle specimens, representing 305 lowest identifiable taxa within 227 genera and 51 families, was collected. One hundred fifteen species (38%) were represented by single individuals. Many more specimens and species were collected from CWD (4129 and 247, respectively) than from FWD (1544 and 162, respectively), but species richness accumulation curves were not significantly different. Many more specimens but an equal number of species were collected from primary forest (3347 and 207, respectively) than from secondary forest (2326 and 207, respectively). Species accumulation curves indicated higher richness in secondary forests. Based on a subset of 71 species represented by 10 or more specimens, 27 species were associated with fresh fine woody debris, 11 species with weathered fine woody debris, four with coarse woody debris decay class I, 14 with coarse woody debris decay class II, and eight with coarse woody debris decay class III–IV. Sixteen species were associated with secondary forests, whereas 28 species were associated with primary forests. Coarse woody debris decay class II taken in primary forests had highest absolute species richness with 156 species. In coarse woody debris species overlap decreased with increased difference in decay indicating faunal succession. Published works related to the study of the ecology of downed woody material are briefly summarized. Recommendations on developing a database of legacy trees for future researchers are given. Notes on the biology and photographs of the 71 species represented by 10 or more specimens are given to provide an atlas of eastern U.S. beetle species most commonly encountered in these habitats