CRS-45 



Food Chain 



The food chain (relationships between production and consumption of plants 

 and animals) in wetlands, as in all ecosystems, is based on primary productivity, 

 in which plants produce plant tissue through photosynthesis. A portion of the 

 tissue is consumed by animals while the plants are living and another portion 

 is consumed after plants die. Wetlands are among the most productive ecosys- 

 tems in the world. Wetlands along the East Coast produce about 5 to 10 tons 

 of organic matter per acre annually. By comparison, moist agriculture produces 

 1.5 tons to 5 tons per acre annually, dry agriculture produces 0.3 tons to 

 1.5 tons per acre annually, and coastal waters (estuarine and nearshore areas) 

 produce 1.0 tons to 1.5 tons per acre annually. 16 / 



Only a few studies have compared food chain values in different wetlands. 



One study of two large drainage systems with extensive wetland areas along the 



Gulf Coast of Florida, the Apalachicola and the Apalachee, concluded that the 



food webs in the two systems which appear to be similar in terms of hydrology 



and physical characteristics were different. The chief researcher determined 



that these differences were caused by a number of factors. 



Overall, these studies indicate that hydrologic cycles and 

 wetland functions which mediate peak inflow and material trans- 

 port can control macro and micro-habitat distribution in the 

 coastal bay ecosystem, as well as nutrient flux and productivity. 

 The form and composition of wetlands-related foodwebs may be 

 the result of combinations of individual population strategies 

 and physically controlled biological interactions .. .Within spe- 

 cific spatial and temporal boundaries, upland (fresh water) wet- 

 lands are inextricably linked, directly and indirectly, with 

 riverine and near-shore productivity. 17 / 



16 / Teal, John and Mildred Teal. Life and Death of a Salt Marsh. Boston, 

 Little, Brown and Co., 1969. p. 196-197. 



17 / Livingston, Robert J. and Orie L. Loucks. Productivity, trophic 

 interactions and food-web relationships in wetlands and associated systems. 

 In Greesen, Clark and Clark (eds.), Wetland Functions and Values, p. 114. 

 Robert Livingston studied both systems for six years. 



