Grassy and Heath Balds

Big Bald

Treeless shrub or grass-dominated ridges and peaks are collectively called "balds". There are two principal types: heath balds and grassy balds (Ramseur 1960). While heath balds are dominated by a heavy coverof ericaceous shrubs, grassy balds aredominated by grasses and sedges, though scattered shrubs may be present. Balds tend occur at middle to high elevations in exposed locations. They range in area froman acre to several hundred acres. Surrounded by forests,balds often include significant rock outcrops, which should be included as parts of these communities.

The origin and maintenance of bald communities, particularly grassy balds,are not fully understood. Heath balds can form and persist in exposed, infertile landscapes that are not hospitable for trees. However, disturbances such as fires and logging that kill trees and cause soil erosion may play a role their formation (White and others 2001). Disturbance likely plays a more important role in the maintaining grassy balds which are shrinking in area due to invasion by woody plants (Lindsay and Bratton 1979). These balds were used as high elevation pastures by European settlers; their livestock prevented invasion by shrubs and trees. Grazing by bison (Bison bison ), elk (Cervus elaphus), and Pleistocene megafauna may have played a role in establishing these open areas (P. Weigel, personal communication). In a survey of grassy balds, Mark (1958) identified 34 areas he considered "true balds" that existed before European settlement and numerous other balds resulting from more recent clearing. During the early to mid-1900s, many grassy balds came under public ownership, grazing ceased and invasion by woody plants accelerated during the latter half of the 20th century. Now the national parks and forests are attempting to preserve some of these balds in an open condition.