| occupancy patterns of regionally declining grassland sparrow populations in a forested pennsylvania landscape. | organisms can be affected by processes in the surrounding landscape outside the boundary of habitat areas and by local vegetation characteristics. there is substantial interest in understanding how these processes affect populations of grassland birds, which have experienced substantial population declines. much of our knowledge regarding patterns of occupancy and density stem from prairie systems, whereas relatively little is known regarding how occurrence and abundance of grassland birds vary ... | 2014 | 24423190 |