Effects Of Climate, Land Use And In-Stream Habitat On Appalachian Elktoe (Alasmidonta Raveneliana) In The Nolichucky River Drainage, North Carolina

The Appalachian elktoe (Alasmidonta raveneliana) is endemic to the Blue Ridge Physiographical Province in western North Carolina and eastern Tennessee. Populations are small and geographically isolated in the headwaters of 10 streams in western North Carolina. Appalachian elktoe populations face a range of threats including climate and land use change, population fragmentation and modification of in-stream habitat. I examined long term (1970-2009) water chemistry and temperature data obtained for 19 streams that historically supported Appalachian elktoe populations. Streams were grouped into two categories: those with apparently stable populations and those with extirpated or severely declining populations. I found that streams with stable Appalachian elktoe populations were cooler with higher dissolved oxygen and lower specific conductance levels compared to streams with declining or extirpated populations. Next, in 2015, I surveyed Appalachian elktoe populations across the Nolichucky drainage at 25 sites and quantified in-stream habitat variables. I used USGS land use data for 1992 and 2011 for all sites. Land use in all streams was predominantly forest with some catchments having >90% forest in both 1992 and 2011. I found that streams with suitable Appalachian elktoe habitat have significantly more forest cover and less disturbance than streams with declining or extirpated populations.