The Responses of Heather-Dominated Vegetation in North-East Scotland to Grazing by Red Deer

Abstract

The response of hill vegetation to controlled grazing by red deer was studied during the course of a project investigating the farming of red deer. Three paddocks, each 8 ha in extent, were chosen for the study. Vegetation surveys to map and describe the plant communities were carried out in 1972 and 1976. Point-quadrats were recorded at the same positions in 1976 and 1979. Heather-dominated, bracken-dominated and wet flush vegetation types were present. Detailed stocking records were kept for all paddocks on the farm. Stocking levels under normal conditions ranged from 1.0-2.5 hind-equivalents (HE)/ha. Higher levels occurred on 1 paddock during periods of hay feeding in winter. Heather-utilization surveys were made in a pilot survey on 1 paddock in 1974 and on all paddocks in 1975 and 1976. Utilization levels ranged from 25 over 60% of the current season''s shoot production. Very similar values were calculated from deer stocking rate, live-weight and intake data, together with estimates of annual herbage production. Floristic changes were confined to heather-dominated vegetation. Old heather was less able to withstand grazing than was young heather, and heather cover was reduced on areas where the stocking rate was consistently above 2 HE ha-1. The relationships among stocking rate, utilization levels and responses of vegetation to red deer grazing are examined, and the role of deer in relation to resource utilization is discussed.