Avian community response to experimental forest management

Abstract

In recent decades, concern for migratory birds has stimulated research assessing the relationships between forest management and bird populations. The Missouri Ozark Forest Ecosystem Project (MOFEP) is a long-term, landscape-scale experiment designed to examine the effects of even-aged (i.e., clearcutting), uneven-aged (i.e., selection cutting), and no-harvest forest management on ecosystem-level processes. The management systems were randomly assigned to three sites each (mean area = 400 ha) with harvest occurring on a different portion of trees every 15 yr over a 100-yr rotation. We used non-metric multidimensional scaling and linear mixed models to investigate the effects of silvicultural treatment and year-since-harvest on bird communities over a 24-yr period, before and after two harvests (1996 and 2011). Bird community compositions diverged among treatments immediately post-harvest, but the differences in community composition and structure began to diminish by 8 yr post-harvest. Species richness was higher in treated stands than no-harvest controls and lowest approximately 10 yr post-harvest regardless of treatment. Species diversity showed a linear decrease with year-since-harvest. Our findings demonstrate that even-aged and uneven-aged forest management can affect bird community composition and structure within the early post-harvest period, but differences may diminish relatively quickly as harvested stands regenerate. We recommend using a variety of silvicultural methods to provide the diversity of habitats needed for the conservation of diverse forest bird communities.