Forests
Northern hardwoods and spruce-fir forests are dominant on all EPI properties, and the young dense stands in the East Branch, Appalachian Trail, and Big Benson-Sebec sanctuaries are ideal habitat for the federally threatened Canada lynx and such species as the pine marten, spruce grouse, northern goshawk, and warblers.
The northern hardwood community comprises sugar maple, yellow birch, American beech, and to a lesser degree white ash, red spruce, red maple, and white pine. The spruce-fir forest community, reduced by lumbering beginning in the mid-19th century, is predominately red spruce, black spruce, and balsam fir, with a minor component of white pine. The spruce-fir forest found in the upland areas of the East Branch sanctuary is part of The Nature Conservancy's Baxter forest block, deemed to be of highest priority for conservation.
Although the age of trees vary greatly in the sanctuaries, areas of old growth are rare. In the East Branch Sanctuary, a unique riparian community of silver maple, red oak, and American elm, with many old trees, can be found along the East Branch of the Penobscot River. Another example of old growth hardwood forest in this sanctuary is located on the rich soils below the cliffs on Lunksoos Mountain. This maple-basswood-ash forest, rare in Maine, has been relatively undisturbed, escaping fires and recent logging. The slopes of Deasey Mountain harbor mature stands of beech-birch-maple forest, dominated by sugar maple, several trees of which are 28 inches in diameter. Spruce-fir forests with old-growth structure also grow on these remote mountains.
Of special note in this sanctuary is a cyclical fire ecosystem of red and white pine, which can be found in the dry sandy soil of the Sandy Stream area.