Habitat associations and 150 years of compositional change in white pine-hemlock-hardwood forests based on resurvey of public land survey corners
AbstractRecent studies have demonstrated substantial changes in the composition and structure of forests in northeastern North America following Euro-American settlement. Especially striking are the -œhomogenization- of tree species composition across the region and a steep decline in conifer abundance. However, the presettlement distribution and subsequent changes for individual species at a finer scale are not well documented. In this study, we examine the presettlement and current distribution of Pinus strobus L. (eastern white pine) on specific habitats in the northern hardwood forest of Wisconsin by re-surveying 201 nineteenth-century land survey corners. The status of P. strobus regeneration was evaluated in the second-growth forests, as well as in a set of remnant old-growth stands on comparable sites. P. strobus occurred across a broad range of habitats in the presettlement landscape, including highly productive, mesic sites where it rarely occurs in the modern forest. Former white pine-hemlock-hardwood forests most often transitioned to Acer or Populus dominance, matching compositional transitions of the overall landscape. Pinus strobus was retained at âˆ¼28% of presettlement locations, but a large majority of these were dry-mesic or lower-productivity mesic/wet-mesic sites. The modern distribution of P. strobus in hemlock-hardwood forests appears to be strongly influenced by historical factors, rather than site limitations. Pinus strobus regeneration was rare across habitats in the modern landscape; thus, the habitat differences that led to differential retention may not be as influential on its future distribution. Our findings indicate that restoration of P. strobus to a wide variety of habitats, including high-productivity mesic sites, is supported by historical information and that active restoration is probably necessary across a spectrum of habitats.
Volume, Issue, Page Number141, 4, 277-293