Forest Composition on the Lake Erie Islands

Abstract

The Lake Erie Island archipelago includes 22 islands which are distinct from the neighboring Canadian and American shores in climate, topography, surface geology and soils. The forest communities of these islands were analyzed for species composition, relationships to environmental factors and similarity to mainland forests. When analyzed by reciprocal averaging ordination, forest stands split into two tight clusters. Upland forests, dominated by Acer saccharum and Celtis occidentalis, occurred where bedrock level> lake level. Lowland forests occurred on sites where bedrock level 65 km2. Dolomites and limestones of Silurian and Devonian age form the bedrock of the region (Core, 1948; Hamilton and Forsyth, 1972). The soils of the upland, exposed areas of the islands are shallow, generally less than 40 cm in depth, have many bedrock outcrops, and are low in available water (Redmond et al., 1971; Musgrave and Derringer, 1981). Most of these upland soils are currently classified as Castalia, very stony, silt loams (Musgrave and Derringer, 1981). Lowland areas and areas not exposed to direct lake action a-re covered by deeper soils (up to 175 cm) formed on limy glacial till (Redmond et al., 1971; Musgrave and Derringer, 1981). The climate of the Lake Erie Islands is temperate, humid-continental (Cooper and Herdendorf, 1977). It differs in several respects, however, from the neighboring Ohio, Michigan and Ontario shores. Due to the buffering effect of the lake, the average frostfree period is 205 days, 27% longer than Tiffin, Ohio, 50 km to the S (Verber, 1955). Significantly less precipitation falls on the islands than on the mainland. Annual