Forest landscape change in the northwestern Wisconsin Pine Barrens from pre-European settlement to the present

Natural disturbance patterns can provide useful information for ecosystem m anagement. Our objective was to provide a detailed spatial picture of the p re-European settlement vegetation cover for the northwestern Wisconsin Pine Barrens and to compare it with the present vegetation cover. We analyzed t he presettlement conditions using an extensive data set comprised of U.S. G eneral Land Office surveyor records from the mid-19th century and related i t to the vegetation cover in 1987 as depicted in a Landsat satellite forest classification. Changes were quantified by calculating differences in abun dance and relative importance of tree species at presettlement time and tod ay. Our results revealed a strong decline of jack, red, and white pine (Pin us banksiana Lamb., Pinus resinosa Ait., and Pinus strobus L., respectively ), accompanied by an increase of oak (Quercus spp.), trembling aspen (Popul us tremuloides Michx.), and other hardwood species. Certain vegetation type s, e.g., red pine and oak savannas, were removed from the landscape. The fo rest density gradient of the presettlement landscape with open savannas and woodlands in the South and denser forests in the North disappeared. These changes, especially the increase in forest cover, are ecologically signific ant because numerous species are adapted to open habitat, which was previou sly created by fire, and their populations are declining.