Immediate responses of wild bee communities to a large-scale burn in savannah habitat

Little is known about the effects of large-scale fires on essential pollinators, such as bees. A large wildfire occurred in the savannahs of Mburucuya National Park, Argentina, providing one year of both pre- and post-burn data. This allowed for an impact assessment of distance from fire edge using species diversity and guild characterization, based on nesting materials and body size, to examine bee community responses to fire. Our results generally agree with those of earlier smaller-scale fire impact studies upon bee communities: immediate declines in species richness and abundance but increases in diversity post-burn as well as similar responses from bee guilds based on nesting requirements. Our study suggests: (1) above-ground nesters are unable to colonize recently burned habitat as quickly as ground-nesters regardless of survival rates in situ, (2) ground-nesting bees, regardless of size, are least affected by distance from foraging or nesting resources, (3) patterns of fire impacts on bees become exacerbated near the middle of a large burn area, and (4) large-scale fires will have a greater impact upon above-ground nesters than do smaller-scale burns.