- December 3, 2019
1:00 pm - 2:00 pm
By Dr. Cathryn Greenberg, Southern Research Station, US Forest Service
December 3, 2019 at 1 PM central time
Webinar abstract: Historically, natural and anthropogenic disturbances in eastern hardwood forests maintained a heterogeneous landscape, with variable levels of canopy cover. Today, prescribed fire is used to restore disturbance-adapted plant communities, and presumably the associated wildlife. Studies in the western US and elsewhere have indicated that wildlife response to fire effects are non-linear and that effects of fire severity and time since fire may interact. However, little is known about wildlife response to prescribed fire or wildfire variability in eastern hardwood forest, especially over a relatively long time period (i.e., >10 years). We conducted multiple short- and long-term studies that together address wildlife responses to single or repeated low- and high-severity prescribed fire, mixed-severity wildfires, season of burning, and other silvicultural treatments in the southern Appalachians. Single, low-severity burns had little effect on any of the wildlife taxa regardless of season of burn. Delayed overstory mortality following repeated applications of low-severity, dormant-season burns led to subtle but non-significant increases in bird species richness. Reptiles and amphibians generally showed little response to single or repeated low-severity dormant season burns. In contrast, high-severity prescribed burns led to increased bird richness and density, and greater lizard abundance. Preliminary data on breeding bird response to wildfires suggest that richness and density may increase with wildfire severity. Our studies also indicate many bird and herpetofaunal species respond similarly to high-severity burns and shelterwood harvests, likely due to heavy reductions in canopy cover after both disturbance types. Terrestrial salamanders may be an exception; our studies showed decreased abundance after shelterwood harvests, but not after high-severity burns. Together, these studies indicate that single, low-severity burns are not an effective tool in creating suitable forest structure for disturbance-dependent breeding bird species, and do not substantially change breeding bird or herpetofaunal communities. In the short-term, substantial forest overstory reduction by timber harvests or high-severity burns may be required to create forest conditions suitable for disturbance-dependent species.