Abstract of Dissertation Presented to the Graduate School of 



the University of Florida in Partial Fulfillment of the 



Requirements for the Degree of Doctor of Philosophy 



FLOOD TOLERANCE OF PLANT SPECIES IN BOTTOMLAND 

 FORESTS OF THE SOUTHEASTERN UNITED STATES 



By 



Russell Francis Theriot 



May 1992 



Chairman: Jerome V. Shireman 



Major Department: School of Forest Resources and Conservation 



Vegetation data on species composition along a hydrologic gradient 

 were collected at 17 bottomland forest sites throughout the southeastern 

 United States. Weighted averages based on importance values calculated 

 from 55 stands resulted in flood tolerance index (FTI) numbers, the 

 optimum position for each species along the defined hydrologic gradient, 

 for 312 identified species. 



Commonly occurring species were evaluated using cluster analyses 

 and discriminant function analyses. Data on tree, sapling, and vine 

 species clustered into distinct groups, with tree species being the most 

 reliable; however, shrubs and herbaceous species did not cluster dis- 

 tinctly. Discriminant function analysis using FTI numbers for tree 

 species proved to be 82 percent reliable in predicting zones. 



The accuracy of the Flood Tolerance Index (FTI) numbers did not 

 vary regionally in the southeastern United States. Therefore, a single 



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