Reversing the fragmentation perspective: effects of clearcut size on bird species richness in Maine

The effects of clearcut size on bird species richness in a forest-dominated landscape were examined. Forty-five clearcuts, ranging in size from 2 to 112 ha and in age from 3 to 10 yr post-cut were selected as study sites in eastern Maine. At least 10% of each clearcut was censused using 1-16 fixed-radius (50-m) circular plots in May and June of 1989 and 1990. Species richness increased with clearcut size but the number of species present per plot did not differ significantly over the size range of cuts. There was some evidence of increased richness in clearcuts up to 20 ha. Of the 15 most common clearcut species in both years, 10 (1989) and 12 (1990) increased in abundance between 2 and 20 ha, beyond which no preference for clearcut size was found. Additionally bird species locations throughout clearcuts were largely independent of distance from the forest edge.