Michael K. Delong and David J. Gibson. Southern Illinois University Carbondale
Forest openings are patches of prairie-like habitat found within dry forests. These openings contain a different plant species composition than the surrounding forest, enhancing local biodiversity. Due to woody species invasion, many forest openings are reduced to series of habitat patches along ridge-tops, meaning that some plant species within these habitat patches may exist as metapopulations and local communities within forest opening patches may exist as metacommunities. We conducted floristic surveys of 36 forest opening patches within three sites in southern Illinois over two years, and used an incidence-function metapopulation model to determine whether any of the vascular plant species’ distributions were consistent with those of metapopulations. We also used null metacommunity models and Monte-Carlo based probability models to determine the pattern of species incidences within the regional metacommunity. We found 123 species of vascular plants at the three sites, of which 53 have spatial patterns consistent with those of metapopulation species. Two of the three sites were significantly nested according to the Monte-Carlo based model. According to the null models, two of the three sites showed a significantly Gleasonian pattern, which indicates groups of species consistently occurring in common within habitat patches. Management practices such as selective thinning and controlled burns are recommended to prevent further habitat loss and to maintain the integrity of the patches as open habitat, which will increase the likelihood of survival for the herbaceous metapopulation species.
