Effects of prescribed fire and fire surrogates on saproxylic Coleoptera in the Southern Appalachians of North Carolina

摘要

We examined the effects of forest management practices (prescribed burning, mechanical, and prescribed burn plus mechanical) on saproxylic forest Coleoptera in the southern Appalachian Mountains of North Carolina. During the 2-yr study, we captured 37,191 Coleoptera with baited multiple-funnel traps and pipe traps, comprising 20 families and 122 species that were used for our analysis. Saproxylic beetle numbers increased greatly from the first year to the second year on all treatments. Species richness and total abundance of Coleoptera were not significantly affected by the treatments, but several families (e.g., Elateridae, Clericlae, Trogositidae, Scolytidae) were significantly more abundant on treated plots. Abundances of many species, including various species of Scolytidae were significantly affected by the treatments. However, these scolytids (Hylastes salebrosus Eichoff, Ips grandicollis Eichoff, Xyloborinus saxeseni Ratzburg, Xyleborus sp., Xyleborus atratus Eichoff) did not respond in the same way to the treatments. Likewise, other Coleoptera such as Pityophagus sp. (Nitidulidae), Hylobius pales Herbst (Curculionidae), and Xylotrechus sagittatus Germar (Cerambycidae) also varied in their responses to the treatments. Species richness was not significantly different for the spring 2003 trapping seasons, but the fall 2003 sample had a higher number of species on mechanical shrub removal only and mechanical shrub removal plus prescribed burning plots compared with controls. Linear regression analysis suggests that increased dead wood caused by hot fires on mechanical plus burn and burn only treatments resulted in increases among various Coleoptera families and species. We saw no evidence that the treatments negatively impacted saproylic species and in most cases they benefited from the disturbances.