Regeneration in Atlantic oakwoods: has deer management had a beneficial effect?

Abstract

Summary The fragmented Atlantic oakwoods of western Europe are a habitat of conservation importance, and in the UK are threatened by browsing of young trees, invasion by exotic species and under-planting with conifers. Previous research showed that small tree saplings were abundant in Scottish oakwoods, but growth was limited by shading and frequent browsing. Within this study, we aimed to assess whether subsequent changes in deer management had resulted in increased sapling growth, and to determine whether planting of oak within lines of brash left after conifer clearance had offered long-term protection from browsing. Pellet group counts at two sites in Glen Nant, Argyll, indicated that use by red deer, roe deer and sheep was lower than five years previously. Within one site, sapling survival was high despite continued browsing, and some saplings, particularly hazel, had gained substantial height increments. In contrast, at the second site, survival was low and the surviving saplings had managed no net growth. At a third site in Glen Etive, Argyll, partially protected by fencing, survival of oak saplings was high, and two thirds had increased in height. Planting oak saplings amongst lines of conifer brash did not offer long-term protection, but within a fenced exclosure saplings had grown substantially, despite vigorous competition from the field layer. Deer management policies within these woods are beginning to show some success in promoting regeneration, but they will need to be continued for a long period to overcome the low growth rates of hardwood species.