Northern Atlantic Coastal Plain Pitch Pine Barrens

This system comprises a group of dry pitch pine woodlands and forests of deep sandy soils ranging from Cape Cod (Massachusetts) south through Long Island (New York) and the famous Pine Barrens of the New Jersey Coastal Plain, with occasional occurrences north to southernmost Maine and south to the Anacostia watershed (Maryland). The vegetation is characterized by a tree canopy of Pinus rigida with a tall-shrub layer dominated by Quercus ilicifolia and a low-shrub layer characterized by Vaccinium pallidum and/or Vaccinium angustifolium. The system is heavily influenced by fire, the composition and structure of its components varying with fire frequency. In general, tree oaks are more prevalent in those stands having a longer fire-return interval; fire frequencies of 8-10 years foster the growth of "pine plains," i.e., dwarf pine stands 1 m in height. Pine barrens with a history of more-or-less biennial burns for lowbush blueberry production may have very few trees and be characterized as sandplain grasslands. Dwarf-shrubs such as Arctostaphylos uva-ursi, Vaccinium angustifolium, Vaccinium pallidum, and Hudsonia ericoides typify the field layer of pine plains and sandplain grasslands. Schizachyrium scoparium is the most common grass (in close proximity to the coast, it may be represented by its close relative Schizachyrium littorale).

Scrub oak stands may occur without pine cover, particularly in low-lying areas that do not intersect the water table, where cold-air drainage inhibits pine growth. North of the glacial boundary, heathlands characterized by Arctostaphylos uva-ursi, Corema conradii, and Morella pensylvanica, and grasslands characterized by Schizachyrium littorale, Schizachyrium scoparium, and Danthonia spicata occur as small (or occasionally large) patches. The Pine Barrens of New Jersey are very similar in structure and composition to those north of the glacial boundary but are characterized by additional species, such as Quercus marilandica, Quercus stellata, Pyxidanthera barbulata, Leiophyllum buxifolium, and others. Where the water table is close to the surface, pitch pine lowland vegetation (described as a separate system) occurs.

The uniqueness of the New Jersey Pine Barrens flora has long been recognized (Stone 1911, Harshberger 1916). More recent treatments by Forman (1979) and Buckhholz and Good (1982) have compiled much of the available information. Pinus rigida is the dominant and characteristic species of this system. It may be found in well-developed tree form or as a short-statured, shrubby ecotype. Pinus rigida may occur as the sole dominant or occur with a variety of oak species, especially Quercus marilandica, Quercus stellata, and Quercus ilicifolia. In some examples Pinus echinata may co-occur.

This system typically occurs on deep well-drained sand deposits. In the coastal regions of the glaciated Northeast, it occurs on outwash plains and morainal deposits. In New Jersey, it occurs on Cohansey sand, which is sometimes overlain with hilltop gravel deposits.

Different fire frequencies and intensities interrupt succession, accounting for variations in forest composition. Periodic severe wildfires with 40- to 100-year intervals have produced oak-pine mixtures over extensive areas of uplands, while more frequent severe fires have created mixtures of pitch pine and shrub oaks. The most frequent and severe fires have created the pine plains (Landfire 2007a).

Fire suppression, urban and agricultural land conversion and landscape fragmentation effecting fire behavior, limiting management options, and introducing invasive plants species. On Long island, New York, pine barrens were noted to have decreased in size to 45% of their original extent (Jordan et al. 2003). The New Jersey Pine Barrens has a complex land-use history; used originally as a source of raw materials for iron smelting, ship building, transitioning over time to severe threats of conversion to residential and commercial development. Walker and Solecki (1999) documented a loss of 317 km2 of pine barrens between 1975 and 1986 to urban and agricultural uses. This represents an annual conversion rate of 0.6%, comparable to the rate of tropical deforestation conversion between 1980 and 1990.

This system is found in the Atlantic Coastal Plain from Delaware Bay northward through the New Jersey Coastal Plain and Long Island (New York) to Cape Cod, Massachusetts, with peripheral occurrences in Pennsylvania (historic), New Hampshire (historic), and southern Maine (Kennebunk Plains and Wells Barren).