may result in broad variations in hydrophytic associations within a given 

 region. For example, a coastal saltwater marsh will consist of different spe- 

 cies than an inland freshwater marsh in the same region. An overview of 

 hydrophytic vegetation occurring in each region of the Nation has been pub- 

 lished by the CE in a series of eight preliminary wetland guides (Table 2) , 

 and a group of wetland and estuarine ecological profiles (Table 3) has been 

 published by FWS. 

 Classification 



34. Numerous efforts have been made to classify hydrophytic vegetation. 

 Most systems are based on general characteristics of the dominant species oc- 

 curring in each vegetation type. These range from the use of general physiog- 

 nomic categories (e.g. overstory, subcanopy, ground cover, vines) to specific 

 vegetation types (e.g. forest type numbers as developed by the Society of Amer- 

 ican Foresters). In other cases, vegetational characteristics are combined 

 with hydrologic features to produce more elaborate systems. The most recent 

 example of such a system was developed for the FWS by Cowardin et al. (1979). 

 Indicators of hydrophytic vegetation 



35. Several indicators may be used to determine whether hydrophytic 



vegetation is present on a site. However, the presence of a single individual 



of a hydrophytic species does not mean that hydrophytic vegetation is present. 



The strongest case for the presence of hydrophytic vegetation can be made when 



several indicators, such as those in the following list, are present. However, 



any one of the following is indicative that hydrophytic vegetation is present:* 



a. More than 50 percent of the dominant species are OBL , FACW, or 

 FAC** (Table 1) on lists of plant species that occur in wet- 

 lands. A national interagency panel has prepared a National 

 List of Plant Species that occur in wetlands. This list cate- 

 gorizes species according to their affinity for occurrence in 

 wetlands. Regional subset lists of the national list, includ- 

 ing only species having an indicator status of OBL, FACW, or 

 FAC, are presented in Appendix C, Section 1. The CE has also 

 developed regional lists of plant species that commonly occur 



* Indicators are listed in order of decreasing reliability. Although all 

 are valid indicators, some are stronger than others. When a decision is 

 based on an indicator appearing in the lower portion of the list, 

 re-evaluate the parameter to ensure that the proper decision was reached. 

 ** FAC+ species are considered to be wetter (i.e., have a greater estimated 

 probability of occurring in wetlands) than FAC species, while FAC- species 

 are considered to be drier (i.e., have a lesser estimated probability of 

 occurring in wetlands) than FAC species. 



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