Reducing predation of conifer seeds by clear-cutting Rubus fruticosus agg.in two montane forest stands

Natural regeneration of forest trees is negatively affected by dense ground cover of brambles (Rubus fruticosus agg.) in montane forests in southweste rn Germany. Seed predation by rodents is one potential factor which may red uce establishment of tree seedlings in these sites. In winter and early spr ing seed predation of two conifers (Abies alba Mill., Picea abies (L.) H. K arsten) was studied in bramble patches and in adjacent cleared plots (6 m x 6 m, respectively) in two montane Abies-Picea stands. Losses of seeds from experimental dishes were higher under bramble vegetation than in the clear ed plots in both forest stands in winter. Seed predation was consistently l ower for Abies than for Picea. The results were similar in early spring. Pr edation was reduced after adding conifer Litter into the dishes. Rodents we re responsible for the seed losses, and rodent abundance was lower in the e xperimental clearings. The results are discussed with respect to natural su ccession on clearings and its practical relevance in forestry, i.e. clear-c utting of bramble patches as a measure to reduce seed predation by rodents. (C) 2000 Elsevier Science B.V. All rights reserved.