The Use of Land-Use Histories to Compare Vegetative Types Between Old Growth and Secondary Forest Communites

Restoring and managing ecological communities to maintain diversity is a fundamental application of ecology. Forest development and ecological succession of abandoned agricultural land should reflect both habitat loss and fragmentation in the surrounding landscape that filter the types of species able to colonize these habitats. Comparing land-use histories of remnant old-growth and newly developing secondary forest communities could be used to understand which species are able to regenerate naturally and which cannot and should allow us to identify which species are most in conservation need. Within the University of Wisconsin Parkside campus, several forest communities of different ages and land-use histories exist, including both old-growth remnants and secondary forest communities that previously existed as agricultural fields. Within these communities, we quantified colonization success through ecological surveys of tree, shrub and herbaceous species using a modified Whittaker design to compare differences and similarities between these forest communities with differing land-use histories. Our results show a clear differences between old-growth and secondary forests in terms of diversity and species composition. Forest development on former agricultural land showed little to no recruitment of the oak and hickory species that still dominate old-growth forests, but tended to be richer in herbaceous species, though of lower floristic quality. However, those secondary forests physically closer to old-growth forest did have some oak regeneration and better recruitment of higher quality herbs. These results suggest that dispersal limitation is a key driver of understory diversity and that assisted dispersal could be a strategy for the conservation of forest and understory diversity. Assisted dispersal within these forest communities could help the regenerative process of species with limited dispersal abilities or no nearby source population. Our next step is to repeat this study over a larger landscape and to start seed addition experiments on UW Parkside’s secondary forests to help facilitate the restoration of oak-hickory forests