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