Northern Upland Forests
Curtis, J.T. 1959. The Vegetation of Wisconsin. Univ. of Wisconsin Press, Madison WI.
Rooney, T. P., S. M. Wiegmann, D. A. Rogers and D. M. Waller. 2004. Biotic impoverishment and homogenization in unfragmented forest understory communities. Conservation Biology 18: 787-798.
Weigmann, S.M. and D.M. Waller. 2006. Fifty years of change in in northern upland forest understories: Identity and traits of "winners" and "loser" plant species. Biological Conservation. 129:109-123.
For more information on these communities please refer to the following websites;