Effects of grazing by mountain hares and red deer on the production and chemical composition of heather.
Heather was protected from grazing for 5 years at 2 moors in north-east Scotland, one grazed largely by mountain hares (Lepus timidus) and one grazed largely by red deer, (Cervus elephas). Protection increased production relative to grazed heather at both moors. At the moor where the heather grew faster, the stock of hares was greater, more current year's growth was removed by grazing, and vegetation, soil and underlying rock were richer in phosphorus. The effects of protection on the chemical composition of heather differed between the 2 moors. Grazing was invariably associated with a decrease in the crude fibre content of the heather, but its effect on nitrogen and P concentrations differed in relation to soil type and possibly amount and type of grazing. Grazing of current year's growth by hares was heaviest at patches of heather rich in P, and by deer at patches rich in N. The grazing preferences of both animals are discussed.