In this ecoregion, high elevation summits are composed of granitic rock or resistant quartsites. Characteristically, they have thin acidic soils, bouldery outcrops, sparse, stunted trees, and a distinct flora. Low elevation summits typically exhibit open-canopy woodlands and tend to be dry, thin soiled and fire-prone. Pines (jack, pitch, red or white) show a preference for these rocky hilltops.
Overall, summits cover 2,758,928 acres, 3% of the ecoregion, but the average size of this feature is 26 acres (+- 55 acres) and 75% of them are smaller than 30 acres in size. Summit size and amounts corresponds closely with elevation and varies with subregion. The Gaspe, Adirondacks and Green/White Mountain subregions contain the largest contiguous summits of the region and also the 78 summits over 4000 feet in elevation that exhibit true alpine conditions.
The TNC portfolio highlights the 3 percent of rocky summits that are the most critical to biodiversity conservation of summit communities and species. This important subset, found in 393 key sites, are well distributed across bedrock and elevation gradients and is 35% unprotected. Please see the NAP Ecoregional Plan 2005, Summit Ecosystems in the Northern Appalachian / Acadian Ecoregion (Anderson, 20065) for more information.