Decline of oak forests and implications for forest wildlife conservation

Despite dominating many forests in eastern North America for over 10,000 years, oaks (Quercus spp. L.) are steadily being replaced by shade-tolerant species, such as red maple (Acer rubrum L.). This shift in forest composition may affect forest wildlife by (1) reducing the availability of hard mast resources, (2) altering the composition and abundance of phytophagous arthropods, and (3) impairing the foraging ability of birds due to differences in leaf and tree physiognomy. Indeed, population dynamics of numerous birds and mammals, ranging from red-headed woodpeckers (Melanerpes erythrocephalus) to black bears (Ursus americanus), have been linked to annual fluctuations in oak acorn crops. Moreover, preliminary research with forest bird communities suggests that abundance and diversity of resident and long-distance migratory birds, woodpeckers, and bark-gleaning species are lower in forests dominated by maple rather than oak. Changing forest composition is an emerging issue in natural resource management and one that can profoundly affect wildlife communities within natural areas and preserves. Given that few empirical data exist to inform management, and that impacts to ecological communities are likely to be profound, more comprehensive research is needed to predict and ameliorate potential outcomes.