ecosystem analysis. While the New 

 England marshes had been the focus of 

 earlier work on the geological 

 development of marshes and of more 

 traditional analyses of plant 

 communities, the "new ecology" of 

 rates and processes on the marsh came 

 largely from the South (Odum 1959). 

 The Georgia salt-marsh work served for 

 many years as the most frequently 

 cited example of this "new ecology," 

 and one of its major early findings 

 was that little (less than 10%) of the 

 live Spartina al terniflora was eaten 

 on the marsh (Smalley i960; Teal 

 1962). One consequence of this 

 finding was an evolving concept of 

 marshes as detritus-based systems in 

 which microbial food chains rather 

 than grazing food chains were 

 important (Odum 1968). Most 

 discussions of marshes and animals 

 have emphasized the potential role of 

 detritus in feeding estuarine and 

 nearshore animals (the "outwelling 

 hypothesis": Odum 1968, 1980; Nixon 

 1980) rather than on animals actually 

 feeding on the emergent high marsh. 



Despite this preoccupation, 

 recent reviews by Daiber (1974, 1977) 

 have shown that our knowledge of salt- 

 marsh animals has been increasing, and 

 that, "There are distinctive plant- 

 animal relationships existing in tidal 

 marshes." Such relationships have 

 been described in detail for at least 

 one New England high marsh by Tiner 

 (1974). In studying Cottrell Marsh in 

 Connecticut, Tiner found over 100 

 species of invertebrates, with at 

 least 10 species associated with 

 Spartina patens , 13 species with 

 Distichlis spicata , 9 with Juncus 

 gerardi , and 6 with Iva frutescens and 

 Juncus g erardi mixed vegetation (Table 

 Ty. While grazing animals (with the 

 occasional exception of some geese and 

 domestic cattle and horses) may not 

 consume much of the vegetation, the 

 presence of animals on the marsh has 

 had a substantial and varied impact 

 (Kraeuter and Wolf 1974; Shanholtzer 



30 



1974). Much of the interest in the 

 preservation of marshes is due to 

 their value as waterfowl and wildlife 

 habitat, while the presence of another 

 group, the insects (i.e. mosquitoes), 

 has been responsible for ditching, one 

 of man's major impacts on the marshes. 



Insects 



The long-standing reputation of 

 salt marshes as breeding grounds for 

 mosquitoes is widespread and deeply 

 rooted. Recognition of the specific 

 interaction between vegetation zones 

 and mosquito distribution seems to 

 date from the work of J.B. Smith 

 (1902) on the marshes of New Jersey. 

 Subsequent study, much of it also in 

 New Jersey, has confirmed that high 

 marsh Spartina patens and Distichlis 

 spicata are the areas with the largest 

 salt marsh mosquito populations (Table 

 8). As Daiber (1974) put it, "as one 

 proceeds in a S partina alterniflora 

 marsh from the frequently innundated 

 tall form toward the less frequently 

 flooded higher elevations, there is an 

 increase in the number of salt marsh 

 mosquito species, particularly Aedes 

 sollicitans . Along with this increase 

 in mosquitoes, there is a tendency to 

 find greater numbers of biting flies." 

 Moreover, the Aedes spp. which breed 

 on the high m.arsh travel farther and 

 feed more voraciously (at least on man 

 and his domestic animals) than species 

 which breed in areas that are more or 

 less permanently flooded. 



The reason for this zonation has 

 not been clearly identified, but 

 Connell (1940) reported that Aedes 

 larvae did not appear in areas of the 

 marshes in Delaware that were flooded 

 more than 25 days each month, and that 

 most breeding was limited to areas 

 where the frequency of tidal 

 inundation was less than 8 days per 

 month. A common explanation is that 

 predation takes place during flooding 

 and that the thick mat of the grasses 

 of the high marsh also makes predation 



