To obtain information on food web structure in salt marshes of the Changjiang （Yangtze） River Estuary, the （ δ3C and δ15N values of primary producers and consumers were determined. The mean δ13C values of 31 d...To obtain information on food web structure in salt marshes of the Changjiang （Yangtze） River Estuary, the （ δ3C and δ15N values of primary producers and consumers were determined. The mean δ13C values of 31 dominant consumers ranged from -23.13‰ to -14.37‰. Except for several species （ Eriocheir sinensis, Sinonovacula constricta and Potamocorbula ustulata）, consumers had interme- diate δ13C values between those of benthic microalgae and Spartina alterniflora. The mean δ15N values of 31 dominant consumers varied between 6.87‰ and 13.33‰, which indicate three trophic levels in salt marshes of the Changjiang River Estuary. A total of 18 macroinvertebrates species and four fish species represented primary consumers with trophic levels ranging from 2.0 to 2.7. Secondary consumers included two maeroinvertebrates and seven fishes with trophic levels varying between 3.0 and 3.9. The consumers were divided into three trophic guilds, i.e., detritivorous/algae feeders, omnivores and carnivores. The detrital food chain was the main energy flow pathway in the salt marsh food web of the Changjiang River Estuary, and the marsh vascular plants were at least as equally important as microphytobenthos for secondary production. The important trophic function of the salt marsh habitats in the estuary is revealed.展开更多
基金The Science and Technology Department of Shanghai under contract Nos 08231200705, 07DZ12038 and 072312032the National Natural Science Foundation of China under contract No. 40876044
文摘To obtain information on food web structure in salt marshes of the Changjiang （Yangtze） River Estuary, the （ δ3C and δ15N values of primary producers and consumers were determined. The mean δ13C values of 31 dominant consumers ranged from -23.13‰ to -14.37‰. Except for several species （ Eriocheir sinensis, Sinonovacula constricta and Potamocorbula ustulata）, consumers had interme- diate δ13C values between those of benthic microalgae and Spartina alterniflora. The mean δ15N values of 31 dominant consumers varied between 6.87‰ and 13.33‰, which indicate three trophic levels in salt marshes of the Changjiang River Estuary. A total of 18 macroinvertebrates species and four fish species represented primary consumers with trophic levels ranging from 2.0 to 2.7. Secondary consumers included two maeroinvertebrates and seven fishes with trophic levels varying between 3.0 and 3.9. The consumers were divided into three trophic guilds, i.e., detritivorous/algae feeders, omnivores and carnivores. The detrital food chain was the main energy flow pathway in the salt marsh food web of the Changjiang River Estuary, and the marsh vascular plants were at least as equally important as microphytobenthos for secondary production. The important trophic function of the salt marsh habitats in the estuary is revealed.
