The rarest communities in Pennsylvania are the black oak savannas found along the coast of Lake Erie. These communities are found on the sandy soils of ancient dunes and beach ridges-relict landforms from thousands of years ago when the Great Lakes’ water levels were higher. Wind and fire, combined with the well-drained, nutrient-poor, sandy soils, historically prevented these areas from developing into forests. Savannas share features of both prairie and forest ecosystems, and are characterized by widely spaced trees interspersed with sparsely vegetated sandy openings (or sand barrens) with low-growing shrubs and herbs including panic grasses, wild lupine, club mosses, bush-clover, bracken fern, and milkweeds. Common shrubs include low bush blueberry, huckleberry, and dewberry. Lichens and mosses are also characteristic components.
Historically, black oak savannas were found from
Sandusky, Ohio through Cleveland and into western
Pennsylvania along the Erie Coast and on glacial sand
ridges and lobes further south. These savannas are
similar to the dry sand beach ridges and dunes within
the Oak Openings Region of northern Ohio and southern
Michigan. We estimate that only about 2 percent of the
black oak savanna that once was in Pennsylvania still
remains. Agriculture, sand and gravel mining, invasions
by non-native plants, fire suppression, and urbanization,
especially in Cleveland and Erie, have all contributed to
the decline of black oak savannas.
There are currently three protected areas along the Erie Coastline in northwestern Pennsylvania and northeastern Ohio that preserve examples of black oak savanna: Presque Isle and Erie Bluffs state parks in Pennsylvania
