Liability of saplings to browsing on a red deer range in the Scottish Highlands.
Abstract
The amount and seasonality of browsing on experimentally planted saplings (<30 cm tall) of Scots pine (Pinus sylvestris), silver birch (Betula pendula), rowan (Sorbus aucuparia) and juniper (Juniperus communis) were observed on rangeland where red deer (Cervus elaphus) was the main herbivore. The effects of clipping on survival of saplings grown outdoors in pots was also studied. The extent to which saplings were browsed varied with location and sp. In general, deer spent most time on the lower slopes of hills and so there was an inverse correlation between alt. and the frequency of browsing on saplings. Tall conspicuous saplings were more liable to browsing than small partially obscured plants. Overall, pine was the sp. most liable to browsing. Juniper and birch were browsed least. Deciduous spp. were browsed most often in summer when they were leafy. There was much less seasonal variation in the browsing of pine and juniper. Pine was easily killed by clipping. Rowan was most tolerant of damage. Pine seems least able to regenerate where deer stocks are large because of its high liability to browsing and consequent heavy mortality. In general, the regeneration of tall woody spp. could be increased, especially at 600-700 m alt., if deer numbers were to be reduced substantially.