A STUDY OF THE EFFECTS OF TRAMPLING ON THE VEGETATION OF LAKE HURON SAND DUNES AT PINERY-PROVINCIAL-PARK

Plots in established health-grassland vegetation and pure stands of Calamovilfa longifolia (Hook) Scribn. on Lake Huron sand dunes were subjected to trampling treatments at various intensities during 1977 and 1978 and were monitored for 1 yr following treatment. Both heath-grassland and Calamovilfa plots given 50 walking passages showed complete recovery within 1 yr after treatment. Heavier treatments (200 walking passages) on Calamovilfa caused a significant reduction in cover 1 yr later. Heavily trampled heath-grassland plots, although visually similar to their controls, had a continued loss of lichen cover over 1 yr. Several species including Arctostaphylos uva-ursi (L.) Spreng., Andropogon scoparius Michx., some Carex spp., Liatris cylindracea Michx. and Rosa blanda Ait. initiated new growth in the fall following heavy trampling treatment, but only shoots of Arctostaphylos survived the winter.