RESPONSES OF BIRD COMMUNITIES TO EARLY SUCCESSIONAL HABITAT IN A MANAGED LANDSCAPE

摘要

I examined short and long term responses of breeding bird communities to the systematic creation of early successional habitat resulting from forest management at a 1,120-ha study site in the Ridge and Valley Province of Pennsylvania, from 1998 through 2002. Species richness and abundances of all species combined and of early successional species increased from precut (1998-1999) to postcut eras (2001-2002) in a treated sector (aspen, Populus spp., and mixed oak, Quercus spp., areas combined), an uncut control sector, and the total study site (treated and control sectors combined) after the fourth cutting cycle. Abundances of a woodland species (Red-eyed Vireo, Vireo olivaceus) and four early successional species (e.g., Field Sparrow, Spizella pusilla) also increased. Over the past 15 years, which spans the third and the fourth cutting cycles at the study site, three woodland species increased significantly in both treated and control sectors (Red-eyed Vireo) or in the treated sector only (Ovenbird, Seiurus aurocapillus, and American Redstart, Setophaga ruticilla). The population of an early successional species (Indigo Bunting, Passerina cyanea) increased significantly in both treated and control sectors. Population trends of three woodland and three early successional species at the study site paralleled statewide or provincial increases in these species over the past two decades. My study has shown that the management of early successional habitats in extensively forested areas will be of benefit for the long term conservation of both early successional and mature forest bird species within a forested landscape.