Table 12, Percent cover of the dominant plant species 

 marsh zones of the Louisiana coast (Chabreck 1972). 



in major 



have used his grouping of the marshes into 

 four broad zones in the discussion of 

 temporal and spatial gradients earlier in 

 this chapter. The 1968 survey (Chabreck 

 1972) is still the best description avail- 

 able of the broad marsh vegetation pat- 

 terns, including the species associated 

 with each marsh zone and their relative 

 importance as indicated by percent cover 

 (Table 12, Figure 35, Appendix 1). 



Spartina a1 terni flora and S^. patens 

 dominate the saline marsh, with Juncus 

 roemerianus , Distichi is spicata and Batis 

 maritima as subdoininants (see Frontis- 

 piece) . Chabreck identified 12 addi- 

 tional species in this vegetation 

 zone. In the brackish zone S. patens is 

 dominant. D. spicata , S^. aTterni flora . 



J. roemerianus 



_ and Sci rpus" olneyi are 



also common species of this zone. Notice 

 that many of the species are the same in 

 both zones, but their order of dominance 

 is changed. Often the brackish marsh has 



a distinct "hummocky" appearance associ- 

 ated with the clumped growth of S^. patens 

 (Figure 36). Forty species are on the 

 brackish marsh 1 ist. 



The intermediate marsh is difficult 

 for the novice to identify. The species 

 are not, on the whole, different from 

 those found in the fresh marsh, but all 

 but one of the four dominant species in 

 these two zones are different. Inter- 

 mediate marsh dominants are again S^. 

 patens , with Phragmites austral is , 

 Sagi ttaria falcata ^ and Bacopa monnieri . 



In the fresh marsh the dominants are 

 Panicim hemitomon , S^. falca ta, Eleocharis 

 Al ternanthera 



philoxeroides . 



increases from salt to 



and dominance decreases. 



are often very diverse with 



different species of grasses and 



spp., and 



Species richness 

 fresh marsh 

 Fresh marshes 

 many 



broad-leaved annuals waxing and waning 

 throughout the growing season (Figure 37). 



38 



