Influence of Fire and other anthropogenic practices on grassland and shrubland birds in New England

The extent of grassland and shrubland habitat in New England has changed dramatically over the past 400 yr as a result of changing land uses.Presently, grasslands and shrublands in New England have been created and maintained primarily as a result of four types of habitat management: mowing, livestock grazing, clearcutting, and prescribed burning.Hayfields and pastures comprise the largest proportion of open land, approximately 718,500 ha.Clearcutting has created extensive shrubland patches in northern Maine, where 3.5% (243,000 ha) of the commercial forestland has been harvested in the past 20 yr, creating ephemeral, early successional shrublands used by a wide variety of warblers, sparrows, and other birds.The most widespread use of prescribed fire is agricultural and takes place on commercial lowbush blueberry (Vaccinium angustifolium) barrens in Maine, where approximately 3,000 ha are burned annually.These barrens are especially important habitats for Upland Sandpipers (Bartramia longicauda) and Vesper Sparrows (Pooecetes gramineus).The scale of ecological prescribed burns in New England for habitat management of endangered ecosystems has been small; in recent years fewer than 300 ha have been burned annually.The effects of burning differ in grasslands versus shrublands.In native grasslands, burning has a strong effect on vegetation structure, which, in turn, has clear effects on most grassland specialist birds.Shrubland fires have less impact on shrubland birds because most of the woody structure remains intact.