“Community Assembly Rules in Southern Appalachian Oak Forests”

Conservation efforts depend in part on adequate understanding of how ecological communities are assembled, and yet there is much about community assembly that is unknown. This study is an attempt to test whether oak subgenera follow a type of assembly rule known as niche partitioning. Niche partitioning is a process by which competition between more ecologically similar species selectively favors the co-dominance of ecologically less similar species. Two null models were constructed to predict the frequency of “co-dominance” in 9 oak species in Southern Appalachian forests if species were distributed randomly. The first null model found evidence that niche partitioning was taking place because there was a greater then expected frequency of co-dominance. This result could have been caused by niche partitioning at the local scale, or environmental differences at larger scales. The second null model failed to account for the occurrence of pure red and pure white oak stands in plots of high abundance. Environmental gradient analysis indicated that red oak was the dominant subgenus across all environmental factors. Conclusive evidence for niche partitioning was not found for the two subgenera of oaks, but the methods developed in this study could grant insight into co-occurrence patterns of other plant species that are known to overlap in distribution. This type of research has the potential to increase our understanding of how evolution is implicated in the macro ecological patterns in plant communities, knowledge that can be used to better manage and preserve forest communities.