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

Abstract

(1) 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. (2) 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. Heatherdominated, bracken-dominated and wet flush vegetation types were present. (3) Detailed stocking records were kept for all paddocks on the farm. Stocking levels under normal conditions ranged from 1-0 to 2-5 hind-equivalents (HE) per hectare. Much higher levels occurred on one paddock during periods of hay feeding in winter. (4) Heather-utilization surveys were made in a pilot survey on one paddock in 1974 and on all paddocks in 1975 and 1976. Utilization levels ranged from 25% to 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. (5) 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. (6) The relationships amongst 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.