The impact of roe deer ( Capreolus capreolus), seedbed, light and seed fall on natural beech ( Fagus sylvatica) regeneration

Abstract

The aim of the present study was to quantify the effects of roe deer browsing relative to the effects of soil preparation, shelterwood density (light) and seed fall. Ultimately, the goal was better silvicultural guidelines to support the use of natural beech regeneration in the close-to-nature forestry context. In spring 1995, an experiment on natural regeneration with three experimental stands (0.28–0.6 ha) was installed in a beech ( Fagus sylvatica) dominated broadleaved forest inhabited by a dense roe deer ( Capreolus capreolus) population (24 deer km −2). The autumn of 1995 offered a large beech mast (stand average 307–1168 beechnuts m −2). Treatments installed included fencing to exclude deer, soil preparation, shelterwood thinning, and the relevant control treatments. Roe deer and soil preparation had dramatic effects on regeneration from the moment the seedlings sprouted in the spring 1996. The regeneration sprouted only sparsely in the unprepared seedbed producing only 5 seedlings m −2 (average across fence treatments) after 2 months, which was reduced to 1 sapling m −2 8 years later. Deer had no significant effect on the regeneration density of the unprepared seedbed. In contrast, the cultivated seedbeds produced initially (after 2 months) up to 191 seedlings m −2 protected by fence, whereas the densities in the unfenced treatments peaked by 22 seedlings m −2. By the end of the study, these densities were reduced to 22 saplings m −2 in the permanently fenced mineral soil seedbed and to 2 saplings m −2 in the unfenced mineral soil seedbed. Regeneration height outside the permanent fence was generally only half the height of the regeneration inside. Additionally, we found significantly positive effects of increasing light and seed fall on regeneration density and of light on regeneration growth. We conclude that the roe deer only reduced the regeneration density of the dense regenerations established in the cultivated seedbeds. However, the regeneration density of the unprepared seedbed was not sufficient to support a future high quality stand. We found no treatment that within the timeframe of this study could support successful regeneration establishment outside the permanent fences. Whether this will change in the future with more time given for the regeneration to establish is yet to be revealed.