Vegetation and avian response to prescribed fire on glade habitats in the Missouri ozarks

Due to fire suppression and land use changes, Missouri glade habitats have undergone long-term declines in area and function leading to consequent declines in many bird species that rely on these habitats. We examined breeding bird species composition and vegetation community composition on three glade sites undergoing restoration with prescribed fire and compared them to three unburned glade sites and three unburned forest sites. Although we documented subtle changes in vegetation characteristics in response to prescribed fire, important structural characteristics, such as canopy cover (>55 at all study sites) and grass cover (<10 at all study sites) remain outside ranges used to characterize glades. Despite this, bird community structure shifted towards grass-shrubland (glade) birds (e.g., prairie warbler (Dendroica discolor), blue-winged warbler (Vermivora pinus), yellow-breasted chat (Icteria virens)) in glades that had been managed with prescribed fire. Using canonical correspondence analyses and stepwise forward logistic regression, we found that grass-shrubland (glade) birds were associated with habitat characteristics such as high stem density of small (06.3 cm diameter at breast height) trees, greater herbaceous cover, greater rock cover and a more open canopy. However, we did not detect any bird species historically associated with glades, such as Bachman's sparrow (Aimophila aestivalis) or field sparrow (Spizella pusilla) on any study sites but did frequently detect red-eyed vireos (Vireo olivaceous) on all sites. Short term application of prescribed fire has not yet produced functionally restored glades. Long term applications of prescribed fire, used in conjunction with mechanical and/or chemical removal of woody overstory, are necessary to achieve restoration at these sites.