Compatibility of prescribed burning with the conservation of insects in small, isolated prairie reserves

摘要

Entomologists have expressed concern that prescribed burning is incompatible with the conservation of insect species richness on small prairie sites. To address this issue, I examined the response and recovery of insect populations after fire within small, isolated tallgrass prairie remnants in northern Illinois, northwestern Indiana, and southeastern Wisconsin. I conducted this research over seven seasons, focused on responses at the species level, distinguished between remnant-dependent and remnant-independent species, and included multiple fire events and sites. I used sweep nets, light traps, sticky traps, and visual searches to gauge population responses and to track negatively affected populations to recovery. Most species (93%) responded consistently to prescribed fires. Postfire responses ranged from positive (26%) to negative (40%) for 151 species representing 33 families and seven orders. Three attributes-remnant-dependence, upland inhabitance, and nonvagility-were significant predictors of negative postfire response. Among negatively affected populations, 68% recovered within 1 year; all 163 populations tracked to recovery did so in 2 years or less. My results support the judicious use of rotational cool-season burning within small, isolated grassland sites. [References: 72]