Vegetation of a Freshwater Dune Barrier Under High and Low Recreational Uses

Abstract

BONANNO, S. E., D. J. LEOPOLD, AND L. R. ST. HILAIRE. Vegetation of a freshwater dune barrier under high and low recreational uses. J. Torrey Bot. Soc. 125:40-50. 1998.-The 27.4 km freshwater dune barrier on the eastern shore of Lake Ontario protects an extensive system of high quality wetlands. The vegetation was previously undescribed, and development pressures required management decisions for which data were needed. The objective of this study was to describe and compare the vegetation under high and low recreational use. We found four community types using hierarchical classification (TWINSPAN): (1) Ammophila breviligulata (beachgrass) (2) Toxicodendron radicans-Vitis riparia-Populus deltoides (brushland) (3) Quercus rubra-Acer rubrum (forest), and (4) Alnus incana (thicket). Reciprocal averaging ordination displayed communities along a first gradient of distance from the beach. A second gradient is likely related to disturbance. Species composition was similar in beachgrass and brushland communities under high and low recreational use. Under low use, forest and shrub thicket were present on the back of the barrier, but were absent under high use. Species richness and ground cover of vegetation, and density of colonizing species were lower on equivalent physiographic zones under high compared to low recreational use.