A Community Analysis for Forest Ecosystems with Natural Growth of Persea spp. in the Southeastern United States


Timothy M. Shearman

Additional Authors:

G. Geoff Wang, Robert K. Peet, Thomas R. Wentworth, Michael P. Schafale, Alan S. Weakley,


Dec – 2018


Carolina Vegetation Survey, forest disease, red bay, swamp bay, US-NVC

Persea borbonia and Persea palustris are two species in the Lauraceae family, native to the southeastern USA. Because of their similar morphologies, many authorities treat these two species as varieties of a more broadly defined group, Persea borbonia. Consequently, the species and communities associated with P. borbonia and P. palustris are not well defined. Extensive mortality has occurred in both species because of laurel wilt disease. Our objectives were to (a) determine whether P. borbonia and P. palustris are associated with different communities, (b) describe the communities and associated species in which P. borbonia and P. palustris occur, and (c) determine which communities support larger individuals of Persea spp. We analyzed data collected from 1988 through 2012 by the Carolina Vegetation Survey. To test differences among plant communities with natural growth of P. borbonia and P. palustris, we used ordination and analysis of similarities. We used cluster analyses and species-indicator analyses to group 388 plots into distinct communities. Results were verified by random forest analyses. We compared basal area of Persea spp. in each community with Kruskal-Wallis multiple comparisons. Persea borbonia and P. palustris communities were significantly different in species composition. Persea borbonia was limited almost exclusively to maritime coastal forests, whereas P. palustris had a larger geographical range, extending from near-coastal settings inland through the fall-line of the sandhills. The cluster and indicator species analyses identified eight unique groups, one for P. borbonia, and seven for P. palustris.