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Shifts In Southern Wisconsin Forest Canopy And Understory Richness, Composition, And Heterogeneity, David A. Rogers, Thomas P. Rooney, Daniel Olson, Donald M. Waller

Biological Sciences Faculty Publications

We resurveyed the under- and overstory species composition of 94 upland forest stands in southern Wisconsin in 2002–2004 to assess shifts in canopy and understory richness, composition, and heterogeneity relative to the original surveys in 1949–1950. The canopy has shifted from mostly oaks (Quercus spp.) toward more mesic and shade-tolerant trees (primarily Acer spp.). Oak-dominated early-successional stands and those on coarse, nutrient-poor soils changed the most in canopy composition. Understories at most sites (80%) lost native species, with mean species density declining 25% at the 1-m² scale and 23.1% at the 20-m² scale. Woody species have increased …