33 



in Zone 3 are overcup oak (QULY) and bitter pecan (CAAQ) , while American 

 elm (ULAM) and sweetgum (LIST) develop the greatest mean importance 

 values in Zones 4 and 5, respectively. 



Other systems have been developed to identify the degree of wet- 

 ness for which a species is best adapted (e.g., Hook 1984, Reed 1988). 

 These systems used qualitative descriptions, such as "most tolerant" or 

 "obligate hydrophyte," and are based primarily on the literature or 

 "expert evaluations" and not on a single coordinated study. Species 

 evaluations were also made by life forms in this study, and no such dis- 

 tinction was made in the other two systems. However, all three systems, 

 including the FTI numbers, were developed to identify a degree of wet- 

 ness for which a species is best adapted. They all have five categories 

 that vary from wettest to driest. Therefore, an obvious comparison 

 would be to compare species having an FTI integer of 2, with the most 

 tolerant and obligate designation, an FTI integer of 3, with the highly 

 tolerant and facultative wet description, etc. 



Species identified in this study are listed along with correspond- 

 ing FTI numbers and ratings of those species from the systems developed 

 by Hook and Reed in Appendix E. Among selected tree species shown in 

 Table 6, all species having an FTI number from 2 to 4 are obligate 

 plants (OBL) in the National List of Plant Species that Occur in Wet- 

 lands: Southeast (Region 2) (Reed 1988) and have a water-logging- 

 tolerance rating of most or highly tolerant (Hook 1984) . All listed 

 species except Pinus taeda that have an FTI number of 6 to 6.5 are fac- 

 ultative upland (FACU) species (Reed 1988) and are rated by Hook (1984) 

 as the least- tolerant species. P. taeda (FTI-6.41) has an indicator 

 status of facultative (FAC) and is rated by Hook as moderately tolerant 



