Pitch Pine (Pinus rigida Mill.) Communities in the Hudson Valley Region of New York

Abstract

This study is part of a coordinated series to describe the pine barrens of New York, communities characteristic of disturbed sites with poor soils. Pitch pine (Pinus rigida Mill.) communities in the Hudson Valley region of New York were found on a sand dune, alluvium, a lacustrine delta and on conglomerate and sandstone outcrops. The alluvium and lacustrine delta sites supported more mesic communities with higher tree and herb species richness than the sand dune site, but lacked a shrub layer. The sand dune, sandstone outcrop and conglomerate sites supported open tree canopy communities in which ericaceous shrubs, especially Gaylussacia baccata, dominated a distinct shrub layer. Community types could be classified into three physiognomic forms. Probably the most disturbed were communities of dwarf vegetation dominated by either pitch pine or scrub oak (Quercus iliczfolia). A second type was characterized by an open canopy of short pitch pines with an extensive shrub layer of scrub oaks or ericaceous shrubs. The third type had a closed canopy of tall pitch pine, red maple (Acer rubrum), red oak (Q. rubra) and/or white oak (Q alba), few shrubs but a considerable number of forest floor herbaceous species. The southeastern area is of particular interest because two of the best known pine barrens in New York, the Albany Pine Bush and the Schawangunk Mountains dwarf forest are lo- cated there. The Pine Bush has been the subject of a number of publications, most ad- dressed to a general audience (Rittner, 1975, for example), but Milne (1985) made a de- tailed study of upland forests and their successional development. He suggested that areas dominated by scrub oak (Quercus ilicifolia) with scattered pitch pine were characteristic of very disturbed sites, especially those that burned often. In the absence of disturbance, Milne believed they would succeed to closed-canopy pitch pine forests, then to areas dominated by a mixture of pitch pine, white pine (Pinus strobus), red oak (Quercus rubra), white oak (Q alba), red maple (Acer rubrum) and white ash (Fraxinus americana). Schawangunk Mountain ridge vegetation was described by McIntosh (1959), who noted that bare rock surfaces of the ridges were covered with pitch pine, sometimes dwarfed, no more than 1-3 m tall. These dwarf ridge top communities graded into taller pitch pine and