A comparison of Lepidoptera communities inhabiting restored and degraded pitch pine-scrub oak barrens in Pennsylvania

Scrub oak barrens were once distributed throughout portions of the northeastern United States. This fire-dependent community covered approximately two million acres in Pennsylvania during the mid-1900s, but was reduced to about 17,600 acres by the late-1900s. Decline of scrub oak barrens is attributed to human development, fire suppression, and colonization by fire-intolerant trees. In recent years, the Pennsylvania Game Commission and The Nature Conservancy have partnered to restore large amounts of degraded scrub oak barrens through prescribed fire. Scrub oak barrens are a state imperiled ecosystem, and support high species richness including several endemic species. For example, scrub oak barrens are known for supporting high Lepidoptera (butterfly and moth) diversity. Our study examined Lepidoptera communities in recently burned scrub oak barrens in northeastern Pennsylvania. We used black light traps and bait stations to compare Lepidoptera diversity and abundance across six burned sites and three degraded unburned sites. Sites were sampled two nights per month in June, July, and August 2012. A total of 13,386 individuals were identified, representing 397 species. Seven species are rare or state listed with three species exclusive to treatment sites. No differences in Lepidoptera species richness, diversity or evenness were found between burned and unburned scrub oak barrens. Several species (n=207) were found in both burned and unburned sites. However, several species were unique to burned (n=54) and unburned sites (n=136). Our data suggest scrub oak barrens should be managed to create a mosaic of burned and unburned patches if Lepidoptera diversity is a conservation goal.