Foodweb analysis of the Orinoco floodplain based on production estimates and stable isotope data
| Autor: | James F. Saunders, Margaret A. Lasi, Stephen K. Hamilton, Marco A. Rodríguez, William M. Lewis |
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| Rok vydání: | 2001 |
| Předmět: | |
| Zdroj: | Journal of the North American Benthological Society. 20:241-254 |
| ISSN: | 1937-237X 0887-3593 |
| Popis: | Stable isotope data and indirect methods for estimating consumer production were used in a foodweb analysis for the Orinoco River floodplain, Venezuela. The ratio of annual production to mean annual biomass (Pa/B) was estimated from mass at maturity for all major categories of consumers. Field data on B then were used to estimate Pa for each major category. Carbon sources for all categories of consumers were identified through δ13C analysis, and trophic shifts in δ15N were used in assigning trophic levels to consumers. The ultimate C source for both invertebrates and fish was algae (phytoplankton and periphyton), even though macrophytes and litterfall from the floodplain forest composed 98% of potentially available C. Production of invertebrate consumers (benthos, rhizofauna, and zooplankton), which occurred almost entirely through 1st-level consumption, was estimated as 14 g C m−2 y−1. Fish, which produced 11 g C m−2 y−1, showed a mean δ15N trophic shift of 1.8 units above the algal C source, s... |
| Databáze: | OpenAIRE |
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