Survivorship of saproxylic beetles in prescribed-burned loblolly pine stands in Georgia

Research on the ecology, distribution, and status of saproxylic beetles in burned forests is needed to prioritize their conservation measures in the southeastern United States. The extent to which saproxylic beetles need to re-colonize forests after fires remains unknown, however, some species may survive fires, thereby obviating the need to re-colonize burned areas. Our objective is to compare the survivorship of saproxylic beetles in logs of two sizes (20 and 33 cm) and decay classes (I and II) in prescribed burned forests. During the spring of 2009, ten logs, 0.5 m in length, were removed from each of three downed loblolly pine trees selected on the basis of diameter and estimated mortality age: 1) small diameter, ~1-2 yrs; 2) large diameter, ~1-2 yrs; and 3) large diameter, ~3-4 yrs. Half of the logs from each tree were randomly placed in a forest scheduled for a prescribed fire, and the other half in an adjacent unburned forest. About five days after the fire, logs from both the burned and unburned forest were placed in insect cages, and samples are being collected once a month for the next six months. All saproxylic insects will be identified to species-level. We hypothesize that survivorship will be higher in unburned logs and large-diameter logs. If fires kill most log-dwelling species, frequent fires will likely favor species with strong dispersal abilities. Hence, saproxylic beetle communities shaped by frequent fires may be more resilient to forest management practices than those in more stable forests.