Fire occurrence was widespread in the central Appalachians pre-European settlement due to Native American ignition and occasional lightning strikes, and continued through European settlement. During this time, low to mixed severity burns supported a suite of ecological communities that were fire adapted. In the mid-20th century, the frequency and intensity of fire decreased regionally, resulting in profound forest composition shifts. Land managers now are prioritizing prescribed fire as a restoration tool in current and transitioning fire dependent communities. However, it is unclear how the re-introduction of fire will affect bat community assemblages, particularly after the severe White-nose Syndrome related population declines of many cave-hibernating bat species. To address this concern we used acoustic detectors to sample bat activity levels in burned and unburned environments to examine habitat and temporal effects of fire on bat species in a repeatedly burned landscape. We found evidence for weak positive fire effects on the northern long-eared bat, Indiana bat, little brown bat, big brown bat/silver-haired bat group, high frequency phonic group, and total bat activity. Temporal effects of fire were only apparent for the big brown bat, where we observed a negative relationship between activity and time since fire. Additionally, historic wildfires may offer a suitable surrogate to assess long-term burn impacts on bats, which in turn can be used to better inform bat and prescribed fire relationships. To examine effects of historic fire on bats, we assessed bat presence using acoustic detections at 16 paired burned and unburned forest stands in Shenandoah National Park. Overall, we found few or mostly equivocal relationships of bat occupancy across species relative to burn condition or time since fire at SNP, indicating there is little evidence to support the concept that fire has a significant ecological effect on bats in this portion of the central Appalachians. Riparian areas are particularly important for bats, and serve as foraging and drinking areas, roost sites, and travel corridors. Because fire impacts dry upland and mesic riparian areas differently, is possible that fire will impact bats differently in burned and riparian habitats. To examine fire effects on bats in riparian and upland habitats, we used paired sampling to monitor bat activity in burned, unburned, riparian, and non-riparian areas. Burn and riparian variables had empirical support to explain activity of all bat species. However, coefficients for these species were small and confidence intervals overlapped zero indicating that differences between habitat configurations were marginal. Our results suggest bats have somewhat species-specific responses to fire that differ between upland and riparian habitats, but that large landscape level prescribed fire has a slightly positive to neutral impact on all bats species identified in at our study site post-fire suppression. / Master of Science / Fire occurrence was widespread in the central Appalachians pre-European settlement from to Native American ignition and occasional lightning strikes, and anthropogenic burning continued through European settlement. During this time, burns supported many ecological communities that were fire adapted, i.e., oak (Quercus spp) and pine (Pinus spp)-dominated types. In the mid-20th century, fire decreased regionally, resulting in changes to forest composition. Land managers now are prioritizing prescribed fire as a tool to restore or re-establish fire dependent communities. However, it is unclear how the re-introduction of fire will affect bats, particularly after the severe White-nose Syndrome related population declines of many bat species. To address this concern, I used acoustic detectors to measure bat activity levels in burned and unburned landscapes to examine habitat and temporal effects of fire on bat species in a repeatedly burned landscape on the northwestern portion of the George Washington National Forest. I found evidence for weak positive fire effects on the northern long-eared bat, Indiana bat, little brown bat, big brown bat/silver-haired bat group, high frequency phonic group, and total bat activity. Temporal effects of fire were only apparent for the big brown bat, where we observed decreasing activity as time since fire increased. Because riparian areas are particularly important for bats in the region as foraging and drinking areas, roost sites, and travel corridors, I also focally compared burned and unburned riparian areas. Burn and riparian variables had support to explain activity of all bat species, however differences between habitat types were marginal. My results suggest bats have somewhat species-specific responses to fire that differ between upland and riparian habitats, but that large landscape level prescribed fire has a slightly positive to neutral impact on all bats species identified at our study site post-fire suppression. Lastly, examining effects of historic wildfires may allow managers to infer long-term burn impacts not yet observable with current prescribed burning. To examine effects of historic fire on bats, I assessed bat presence using acoustic detections at paired burned and unburned forest stands in Shenandoah National Park. Overall, I found few relationships of bat occupancy across species relative to burn condition or time since fire, indicating that fire likely does not have a significant ecological effect on bats in this portion of the central Appalachians.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/86534 |
| Date | 10 July 2017 |
| Creators | Austin, Lauren V. |
| Contributors | Fisheries and Wildlife Sciences, Ford, W. Mark, Powers, Karen E., Silvis, Alexander |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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