Avian species richness and reproduction in short-rotation coppice habitats in central and western New York: species richness and density increase rapidly with coppice age, and are similar to estimates from early successional habitats.

摘要

Aim: To investigate avian species richness, density and breeding success in short-rotation woody crops (SRWC) planted as potential source of renewable bioenergy. Methods: We carried out regular bird censuses and systematic nest searches in dense plantations of fast-growing willow and poplar clones coppiced at three- to five-year intervals in New York, USA. Results: Thirty-nine species regularly used SRWC plantations; of these at least 21 were confirmed breeding on study plots. A total of 63% of the variation in bird species richness was explained by the number of years since coppicing and plot area together. Both the richness and overall density of avian species in SRWC plots was similar to estimates obtained from the Breeding Bird Census for more typical shrublands and successional habitats (e.g. abandoned fields, second-growth forest, regenerating clearcuts). Nesting success for the most common species was within the range of values from published studies in alternative nesting habitats, although often at the lower end of the range. Brood parasitism by Brown-headed Cowbirds Molothrus ater, often an important factor in nesting success, was extremely low on the study plots. Conclusion: If planted on a fairly large scale with staggered coppicing schedules, SRWC plantations would help to maintain breeding populations of birds that range from open-habitat species to woodland species. There is no evidence that conversion of substantial land area to SRWC would result in an 'ecological trap' for species common in the farmland-small woodland landscapes of the northeastern USA.