Impact of beaver foraging on structure of lowland boreal forests of Algonquin Provincial Park, Ontario

摘要: Abstract We investigated the effects of beaver browsing on woody plant community structure lowland boreal forests by measuring spatial variation in diversity, foraging rates and sapling recruitment at 15 ponds occupied beavers one other pond abandoned them southern Algonquin Park, Ontario. Beavers fed preferentially a small number deciduous species cut stems declined sharply with increasing distance from ponds. The maximum stem diameter was 45.3 cm, average 15.1 cm. Conifers increased relative dominance to presence beavers. Plant richness, basal area diversity peaked intermediate distances (ca. 25 m) Sapling non-preferred positively related pressure. Total abundance four preferred (trembling aspen, red maple, sugar maple beaked hazel) were negatively However, including alder willow (also beavers) these patterns changed, becoming Diversity changed three years after abandonment. around similar Hence, selective does not completely shift towards species. These observations suggest that do act as keystone species, i.e., they increase importance dominant (conifers). gaps create facilitate regeneration both their food future ramifications forest structure.