Ecological impacts of increasing numbers of deer in British woodland

In recent decades, serious impacts on woodland regeneration have become widespread in Britain as a consequence of increasing numbers of deer. Concern has also been growing about possible effects of deer on the wider ecology of woodland. In April 2000, the Forest Ecology Group of the British Ecological Society held a meeting on 'Ecological Impacts of Deer in Lowland Woods'. This paper summarizes the main issues that emerged from papers presented at that meeting, several of which are published in this special issue of Forestry. The probable causes of the increases in deer populations and the problems posed for deer management are briefly considered. There are convincing reasons to believe that for a wide range of taxa, abundances of particular species and overall community composition can be strongly modified by increasing numbers of deer. Such ecological changes are probably well advanced in many British woods as a result of recent intensified grazing. The general effect of sustained heavy grazing and browsing is a reduction in the richness of biological communities. There are, however, considerable differences among species in their responses and heavy grazing is not detrimental to all species. Responses of many species will be non-linear, with intermediate levels of deer pressure being beneficial in many cases. Ecologists have an important role to play in gaining a better understanding of these effects; this is essential if informed decisions are to be made about deer management at both local and regional levels. However, such research presents many methodological challenges.