Composition, Structure, and Trajectories of Great Lakes Coastal Pine Forests in Relation to Historical Baselines and Disturbance History

Abstract

Pine forests have historically been an important component of Great Lakes coastal ecosystems that provide wildlife habitat and other ecosystem functions. The area covered by coastal forests and the dominance of pines within remaining forests have been greatly reduced over the past ∼200 y by logging, development, and other anthropogenic activities. This study assessed stand history and composition of remnant coastal pine forests and compared contemporary stands to historical baselines to support restoration efforts in these ecosystems. Sampling was conducted in 23 stands at eight sites along the shores of Lakes Michigan and Superior in Michigan, U.S.A. and was focused on stand composition, age structure, and disturbance history. Current data were compared with data from presettlement Public Land Survey records in coastal pine forests across the region. Composition in contemporary forests differed greatly from presettlement conditions in southern sites and was significantly, but not as strongly, different in the northern part of the region as well. Pine dominance in remnant stands was lowest with moderate levels of pine-logging-era canopy removal. Comparisons of overstory and understory dominance suggested a continued trend away from pine dominance toward mesophytic species in all stands. Restoration of disturbance regimes (particularly surface fires) and open canopy conditions may be necessary to maintain a pine component in these ecosystems.