The importance of hardwood trees in the longleaf pine forest ecosystem for Sherman's fox squirrels

Abstract

The longleaf pine ( Pinus palustris) forest, one of the most diverse yet endangered ecosystems in North America, has received considerable interest from conservation biologists. Longleaf pine ecosystem management focuses on maintaining open mature pine savanna with reduced hardwood levels. Sherman's fox squirrel ( Sciurus niger shermani), a near obligate species of the open mature longleaf pine forest and a species of concern, relies on embedded hardwood trees for food and shelter but avoids closed-canopy hardwood forests. So where is the middle ground of hardwood importance to the squirrel? Ecosystem-scale conservation focusing on intensive removal of hardwoods from within the longleaf pine matrix, may negatively impact Sherman's fox squirrels. To understand the importance of hardwoods to Sherman's fox squirrels, we conducted a radio telemetry study focusing on habitat components within fox squirrel home ranges. Our results suggest a range of acceptance to the ratio of mature pine to hardwood within longleaf pine forests with an 80% estimated probability of home range use when canopy cover is comprised of 88.2% mature pine savanna to 11.8% hardwood cover. Conservation and restoration efforts should maintain individual mature hardwood trees and small patches within the longleaf pine forest ecosystem to benefit Sherman's fox squirrel.