30 



cover type, which represents differences in the spatial rela- 

 tion of emergent cover to open water or exposed bottom 

 soil. The zones of Stewart and Kantrud's system are 

 readily related to our water regime modifiers (Table 5), 

 and the subclasses are roughly equivalent to our Water 

 Chemistry Modifiers (Fig. 8). 



Wetlands represent only one type of land and the classi- 

 fication of this part separate from the rest is done for prac- 

 tical rather than for ecological reasons (Cowardin 1978). 

 Recently there has been a flurry of interest in a holistic 

 approach to land classification (in Land Classification 

 Series, Journal of Forestry, vol. 46, no. 10). A number 

 of classifications have been developed (e.g., Radford 1978) 

 or are under development (e.g., Driscoll et al. 1978). Parts 



Table 5. Comparison of the zones of Stewart and Kantrud's 

 (1971) classification with the Water Regime Modifiers 

 used in the -present classification system. 



Zone 



Water Regime Modifier 



Wetland-low-prairie 

 Wet meadow 

 Shallow marsh 

 Deep marsh 



Intermittent-alkali 



Permanent-open- 

 water 

 Fen (alkaline bog) 



Non-wetland by our definition 

 Temporarily flooded 

 Seasonally flooded 

 Semipermanently flooded 

 Intermittently exposed 

 Intermittently flooded (with eusaline 



or hypersaline water) 

 Permanently flooded (with mixo- 

 haline water) 

 Saturated 



STEWART AND KANTRUD 

 (1972) 



APPROXIMATE 



SPECIFIC 

 CONDUCTANCES 



((jMhos) 



THIS CLASSIFICATION 



SALINE 



HYPERSALINE 



POLYSALINE 



SUBSALINE 



60,000 

 45,000 



30,000 



1 5,000 MESOSALINE 



EUSALINE 



BRACKISH 



MODERATELY BRACKISH 



SLIGHTLY BRACKISH 



8,000 

 5,000 



2,000 



800 

 500 



OLIGOSALINE 



MIXOSALINE 



FRESH 



FRESH 



Fig. 8. Comparison of the water chemistry subclasses of Stewart and Kantrud (1972) with Water Chemistry Modifiers used in 

 the present classification system. 



