Prairie fen wetlands are one of the most biodiverse ecosystems in the temperate regions of the world. Throughout their limited range in the glaciated Upper Midwest, conservation and restoration efforts are underway to preserve biodiversity and hydrological functions of these threatened systems. Scientific studies are still needed to inform conservation planning and restoration. This study was designed to investigate the potential relationships of site- and landscape-level factors with prairie fen plant diversity, using plant diversity as a proxy for overall ecosystem health. Total, native, and exotic species richness, Shannon’s Diversity Index, exotic relative abundance, coefficient of conservatism, and Floristic Quality Index were calculated for the plant diversity data at each of 19 sites. Explanatory variables of related to site (water and soil chemistry, area, perimeter-area ratio, connectivity) and landscape (land cover at 100m, 500m, 1000m, and watershed) were used to develop generalized linear models. We used stepwise corrected Akaike’s Information Criterion to reduce/select variables from both site- and landscape-levels. Redundancy analysis variation partitioning was used to measure the relative contribution of site- and landscape-level variables and residuals for each diversity measure.
Results/Conclusions
Our analysis indicated area was an important site-level variable in selected models for all diversity measures. Exotic species have a stronger relation with immediate surroundings (100 m) while other measures have stronger relations with surrounds in the watershed or 1000m from the site. Diversity measures related to site capacity and diversity of species (native species richness and Shannon’s Diversity Index) were significantly and strongly related to site-level variables, while measures relating to site quality (i.e., exotic relative abundance, mean coefficient of conservatism, Floristic Quality Index) were related significantly with landscape-level variables. Our results suggest that if high diversity is the management goal preserving larger areas and hydrology of prairie fens should be a priority. If maintaining the habitat for prairie fen specific species is a priority, preservation and restoration of surrounding landscape, especially forest and wetlands would be important.