Effects of Selective Logging on Breeding Bird Communities in Bottomland Hardwood Forests in Louisiana

Abstract

Bottomland hardwood forests of the southeastern United States support a rich avifauna, including >20 species of conservation concern; understanding the impact of land use practices on these communities is critical to their conservation. Selective timber harvesting is a common management practice in southern bottomland hardwood forests, but little research has examined impacts >5 years after harvesting. We studied breeding bird communities in selectively harvested bottomland forests in northeastern Louisiana during 2003–2004. We conducted point counts in recently harvested stands (1–5 yr postharvest) and older harvests (12–18 yr postharvest); we paired each with a reference stand that had not been harvested for >30 years. Of 35 species with sufficient detections for analysis, we found evidence that abundances of 17 species differed among treatments. Three species were sensitive to creation of canopy openings by timber harvests, including 2 species of concern in the Mississippi Alluvial Valley, USA, prothonotary warbler (Protonotaria citrea) and Acadian flycatcher (Empidonax virescens). However, 4 species of concern often associated with densely vegetated canopy gaps were more abundant in older harvests than in reference stands: Swainson's warbler (Limnothlypis swainsonii), hooded warbler (Wilsonia citrina), white-eyed vireo (Vireo griseus), and Kentucky warbler (Oporornis formosus). As expected, a suite of species typically associated with shrub and forest-edge habitats was more abundant in recent harvests than in reference stands. We conclude that selective logging has a strong influence on bird abundances in both recent and older harvests in bottomland forests. With the exception of Acadian flycatcher, older harvests and reference stands supported similar abundances of the species typically found in closed-canopy bottomland forests. In addition, older harvests supported substantially higher abundances of gap-dependent species than other treatments. Our results should be useful to land managers and conservation planners evaluating short- and long-term effects of timber management practices on breeding birds in the Mississippi Alluvial Valley. However, measures of breeding productivity are necessary to evaluate more fully the habitat quality of harvested forests.