Type: report

Article abstract: To investigate the role of large-scale wildfires on the scorpion and solifugid species within San Diego County of southern California, we examined specimens that had been collected from four study sites distributed across the region from both before and after the 2003 wildfires: 1) Santa Ysabel Preserve, 2) Rancho Jamul Ecological Reserve-Hollenbeck Canyon Wildlife Area, 3) Little Cedar Ridge, and 4) Elliott Chaparral Reserve. In October and November of 2003, large-scale fires burned approximately 130,000 ha of San Diego County. We collected data to assess fire impacts on the local solifugid and scorpion communities using drift fence arrays with pitfall traps. Sampling prior to the fires was conducted between May 1998 and June 2003. Post-fire sampling was conducted between January 2005 and September 2007 with the objective of identifying impacts of wildfire on the scorpion and solifugid communities. We calculated monthly detection frequencies of each species to test for differences in seasonal activity patterns between scorpions and solifugids. We compared total species richness, rates of species accumulation, and average species richness detected per sample occasion between preand post-fire sample periods to describe major differences in the pre- and post-fire datasets. To test for the effects of wildfire on the community, we compared pre- to post-fire differences in the average species richness per sample occasion between burned and unburned plots, as well as modeled the effects of vegetation, plot condition (burned or unburned), and their interaction on the species richness measures for post-fire periods. We also tested for associations between vegetation types and individual scorpion and solifugid species and for the two most dominant species, constructed site occupancy models to compare occupancy among sites, vegetation types, and between burned and unburned plots.