Description:    Intense harvesting and slash fires during the late 1800s and early 1900s led to homogenization throughout the Great Lakes region via the conversion from tamarack, pine, and spruce forests to aspen forests, which are supported by the forest products industry. Subsequently, mesophication occurred in the eastern United States due to fire suppression, transforming oak woodlands to mixed mesophytic forests. We explored both homogenization and mesophication at a regional scale by quantifying changes in community composition and density between historical General Land Office survey points and current USDA Forest Analysis and Inventory plots for Minnesota’s Laurentian Mixed and Eastern Broadleaf Forest provinces. We used the Morisita plotless density estimator and applied corrections for surveyor bias to estimate density for historical forests and we used known densities of FIA plots to predict current densities with random forests, an ensemble regression tree method, and terrain and soil predictor variables. Of the 43 ecological units used in the analysis, only one current community was similar to its historical counterpart. Within the Laurentian Mixed Forest province, forest density of primarily mature aspen stands is reduced slightly today compared to the tamarack-dominated forests of the past. Conversely, in the Eastern Broadleaf Forest province, forest densities have increased compared to historical pine and oak woodlands, due to increases of densely growing, fire-sensitive species. Ordinations of functional traits and structure showed substantial changes between current and historical communities as well as reduced differentiation among current communities compared to their historical counterparts. Homogenization in the Laurentian Mixed Forest is occurring by transition from early-successional to late-successional species, with associated changes in forest ecosystems, and homogenization and mesophication in the Eastern Broadleaf Forest are occurring by transition from disturbance-stabilized genera of open forest ecosystems to non-disturbance-dependent genera of dense forests. Despite different starting points of historical forest ecosystems in the Laurentian Mixed Forest and Eastern Broadleaf Forest, we found homogenization and mesophication to be interrelated in the convergence of composition and densities along a common trajectory to dense forests composed of late-successional species in Minnesota. Content Type Journal Article Category Research Article Pages 1-18 DOI 10.1007/s10980-012-9805-5 Authors Brice B. Hanberry, Department of Forestry, University of Missouri, 203 Natural Resources Building, Columbia, MO 65211, USA Brian J. Palik, USDA Forest Service, Northern Research Station, Grand Rapids, MN 55744, USA Hong S. He, Department of Forestry, University of Missouri, 203 Natural Resources Building, Columbia, MO 65211, USA Journal Landscape Ecology Online ISSN 1572-9761 Print ISSN 0921-2973