Avian communities of managed and wilderness hemiboreal forests

We compared breeding bird communities of hemiboreal forests in multiple-use managed forests and relatively unmanaged wilderness forests in northern Minnesota. A total of 240 point-count locations, 120 in each of the managed and wilderness areas, were sampled three times across ten paired transects in 2010 and 2011. Transects were paired near lotic systems that cross each management type, with half of the points adjacent to (100m) or distant (400m) from the riparian corridor. Total number of individuals and species richness detected per count were higher within the unmanaged forest (F_1,9=9.76, p=0.01; F_1,9=11.17, p<0.01) and forest adjacent to the riparian corridor (F_1,9=28.30, p<0.001; F_1,9=42.12, p<0.001). These results were negatively correlated with increased area of regenerating forests (mainly from logging) within the managed forest and positively correlated with tree species richness and overstory height of forest stands within the wilderness forest. Of 35 species analyzed individually, Black-capped Chickadee (Poecile atricapillus), Brown Creeper (Certhia americana), Canada Warbler (Cardellina canadensis), Golden-crowned Kinglet (Regulus satrapa), Least Flycatcher (Empidonax minimus), Red-breasted Nuthatch (Sitta canadensis), Winter Wren (Troglodytes hiemalis), and Yellow-bellied Flycatcher (Empidonax flaviventris) were more common in the wilderness forest. Only the Mourning Warbler (Geothlypis philadelphia) and Chipping Sparrow (Spizella passerina) were more common in the managed forest. Species associated with mature or mixed forests tended to be found in the wilderness area at higher densities, but most species associated with early-successional habitats did not differ between the managed and wilderness landscapes. Results suggest that forests with natural disturbance and succession regimes provide habitat for a higher density and richness of bird species. Responses by breeding birds were similar in both management types regarding distance from riparian areas. To adequately provide for effective conservation of the avian community, forested regions should include wilderness forests.