1. Department of Ecosystem Science and Management; Penn State University; University Park Pennsylvania USA
2. Pasture Systems and Watershed Management Research Unit; USDA Agricultural Research Service; University Park Pennsylvania USA
3. Pasture Systems and Watershed Management Research Unit; USDA Agricultural Research Service; East Wareham Massachusetts USA
4. Department of Agriculture, Food and Resource Sciences; University of Maryland Eastern Shore; Princess Anne Maryland USA
5. Department of Natural Sciences; University of Maryland Eastern Shore; Princess Anne Maryland USA