The Allegheny Highlands forests are a temperate broadleaf and mixed forests ecoregion located in a large part of the Allegheny Plateau physiographic province, including both unglaciated and glaciated portions, in Pennsylvania and New York within North America, as defined by the World Wildlife Fund. The United States EPA defines the area as belonging to the Northern Central Appalachians and Northern Appalachian Plateau and Uplands ecoregions.
Setting
The ecoregion consists of four separate blocks of mixed forest surrounded by lower lying areas of hardwood forest as follows: the Northern Allegheny Plateau in New York State and Pennsylvania including the Catskill Mountains, the Poconos, the Finger Lakes and French Creek areas. The geology is diverse, with Paleozoic shales, sandstones, limestones, and chert. The topography is generally hilly with some deeply cut river valleys and many waterfalls. Areas of the north and central Appalachians; the western Allegheny Plateau in western Pennsylvania and Ohio; and the upland plain around Lake Erie and Lake Ontario. The Finger Lakes overlap the Eastern Great Lakes Lowland Forests ecoregion to the north. These lakes were created by glaciers, which scoured, widened, and deepened existing river valleys. Glacial debris then dammed rivers and created the lakes.
Climate
The North Central Appalachians ecoregion has a severe mid-latitude humid continental climate, marked by warm summers and snowy, cold winters. The mean annual temperature ranges from roughly 3 °C to 8 °C with an average of 1082 mm annual precipitation. The Northern Appalachian Plateau and Highlands ecoregion, also a severe mid-latitude humid continental climate, has a mean annual temperature of 7 °C, seeing an average of 969 mm of precipitation.
Flora
Most of this forest was cleared in the late-19th and early-20th centuries. Although all individual trees species still remain, their quantities and distribution are radically different from the forest's original state. The pre-settlement forests were predominantly hemlock (Tsuga), white pine, and northern hardwoods forests. Most of these stands were dominated by eastern hemlock and beech. The Finger Lakes area has a particularly rich mixture of woodland, while the pinewoods in the Pocono Mountains are a unique habitat.
Upland hardwood forests include red maple (Acer rubrum), American beech (Fagus grandifolia), black cherry (Prunus serotina), and black birch (Betula lenta).
Allegheny hardwood forests consist of black cherry (Prunus serotina), white ash (Fraxinus americana), and tulip poplar (Liriodendron tulipifera).
Mixed-oak forests of northern red oak (Quercus rubra), white oak (Quercus alba), eastern black oak (Quercus velutina), and scarlet oak (Quercus coccinea) grow along major river drainages and on steep, drier slopes.
Northern hardwood forests include sugar maple (Acer saccharum) and American beech (Fagus grandifolia). Also common are yellow birch (Betula alleghaniensis), eastern hemlock (Tsuga canadensis), red maple, black cherry, and eastern white pine (Pinus strobus). Hemlock tends to follow stream drainages, while white pine prefers drier ridgetops. White ash, American elm (Ulmus americana), basswood (Tilia americana), and hop hornbeam (Ostrya virginiana) can occur locally.
Boreal forests occur at high elevations, particularly on the peaks of the Catskill Mountains. These forests include balsam fir (Abies balsamea), paper birch (Betula papyrifera), mountain ash (Sorbus americana), and red cherry (Prunus pensylvanica). Wild raisin (Viburnum cassinoides) and mountain holly (Ilex mucronata) are shrubs that grow in high elevation swamps, bogs, and ledge tops.
Animals
Wildlife of the forest includes a wide variety of animals, reptiles, fish and birds. Bobcats, which are known to live in a wide variety of habitats, including boreal coniferous and mixed forests in the north like the Allegheny Highland forest. The American black bear is common throughout the Pacific Northwest's forests and mountains. They are also found in forests throughout Canada, Alaska, the Rocky Mountains, the upper Midwest, parts of the southern U.S., the Appalachian Mountains, and down into Mexico. Red foxes prefer areas where different habitats—forests, fields, orchards and brush lands—blend together. Gray foxes also prefer a landscape mosaic, but will thrive in dense northern hardwood and mixed forests where they often inhabit thickets and swamps. Coyotes can be found in a variety of habitats including fields, plains, and bushy areas.