US-IALE 2018

AUTHORS: Matthew E. Fagan*, University of Maryland, Baltimore County; Douglas C. Morton, Bruce D. Cook, Jeffrey Masek – NASA Goddard Space Flight Center; Feng Zhao, Xi'an University of Science and Technology; Ross F. Nelson, NASA Goddard Space Flight Center; Chengquan Huang, University of Maryland, College Park

ABSTRACT: Commercial pine plantation monocultures in the southeast U.S. annually produce the greatest volume of industrial roundwood in the world. The area of industrial forest has expanded dramatically in recent years, but the potential impact of pine monocultures on the remaining natural forest habitat has not been widely examined. Pine plantations are regularly harvested every 10 to 15 years and may not function as habitat for many species of interest. Here, we integrate a novel map of plantation forest extent in 2011 with historical maps of forest disturbance to assess the fragmentation of natural habitat in the southeastern U.S. If pine plantations are not considered to be forest habitat, forest area decreases by 28%, core forest area decreases by a third, and the area within 30 m of a forest edge increases by 50%. Because of the rapid harvesting and regrowth of pine monocultures, we further characterized the age and intermittency of current forest-plantation and forest-nonforest edges across the region. We found that repeated disturbance and regrowth of regional forests has caused intermittent edges to be the dominant edge type, and that the majority of intermittent edges are associated with extant pine plantations. We conclude that edge effects in regions dominated by industrial forests are potentially widespread, but their magnitude is likely to be contingent on complex historical dynamics of disturbance and regrowth.