Effects of even-aged forest management on early successional bird species in Missouri Ozark forest

Abstract

I examined the effect of different clearcut sizes on species richness, abundance, and reproductive success of five early successional birds: Yellow-breasted Chat (Icteria virens), Indigo Bunting (Passerina cyanea), White-eyed Vireo (Vireo griseus), Hooded Warbler (Wilsonia citrina), and Prairie Warbler (Dendroica discolor) in the Missouri Ozarks. Ten clearcut stands were surveyed. The stands ranged in size from 0.95 to 11.38 ha and were 5-7 years old post-cut at the time of the survey (2001-2003). A total of 41 bird species were recorded; of these, 12 were considered early successional specialists. A positive relationship between clearcut size and avian species richness was found (r2= 0.6975, P<0.05), indicating that the number of species was higher in larger clearcuts than in smaller openings. Clearcut size had a significant effect on the relative abundance on four of the five early successional species; Hooded Warbler abundance was not affected by clearcut size. Statistical analysis of reproductive success was difficult to achieve because of the low number of nests found (n= 51). My results suggest that even-aged treatments of different size in a large forest matrix had a positive effect on early successional birds. Implementation of even-aged practices in a forest-dominated landscape create habitat for early successional birds. Larger clearcuts, between 3 and 10 ha in size, sustained greater abundance of early successional birds and did not affected significantly mature forest bird species.