Northern Lowland Forests
Contemporary Results (cont.)In general, species that increased at northern wet-mesic sites tended to be native forbs that are biotically pollinated and abiotically dispersed. Although the sites in this study are dominated by native species, exotic species have significantly increased at most of the sites over the past 50 + years, from four sites and 12 quadrats in 1952 to twenty sites and 121 quadrats in 2005.
Drivers of Change
Exotic species are becoming more ubiquitous across the Wisconsin landscape and are showing up in a variety of plant communities in greater numbers. This contributes to the increase in exotics observed in northern wet-mesic communities. In this study, mature cedar was found to be increasing in abundance. However, the regeneration of cedar is being adversely affected by a variety of site-specific factors, which include yearly variations in seed production, absence of rotting logs for successful seed regeneration, and increased deer herbivory. These factors could lead to future plant changes in northern wet-mesic communities, if regeneration is not adequate, when the current cedars senesce. Human development also is a large challenge that northern wet-mesic communities face. Four sites (10% of the study) experienced major vegetation changes due to direct human impact. Three of the sites were altered hydrologically by road building activities and one site was drained and filled for a subdivision.
Further work on northern wet-mesic forest communities is not anticipated at this time. Our thanks to Matt Bushman for his contribution of text and photos relating to Northern Wet Mesic Forests.
Bushman, M. 2006. Plant species change in northern Wisconsin wet-mesic forest communities from 1952 to 2005. Research Paper, University of Wisconsin-Stevens Point.
Curtis, J.T. 1959. The Vegetation of Wisconsin. University of Wisconsin Press, Madison. 657pp.
For extra information on these communities also refer to the following websites;