| Abstract: | Stable-isotope ratio signatures of primary producers in a coastal wetland and in adjacent offshore waters of western Lake Superior indicated that phytoplankton are the primary source of carbon for the grazing food web of this ecosystem. This study outlines the possible roles of other autotrophs in this regard. Isotopic signatures of macrophytes reflected their life-form-associated constraints on diffusion of inorganic carbon. Data indicated that differences between wetland and lake phytoplankton may be explained by the isotopic signatures of their dissolved inorganic carbon (DIC) sources. Results of an in situ experiment showed that respiration associated with macrophyte decomposition is capable of enriching surrounding water with significant amounts of *d13C-depleted DIC and lowering the net *d13C ratio of DIC in water in low-turbulence situations. The *d13C ratio for wetland phytoplankton may be depleted relative to pelagic algae because the fixed carbon is derived from decomposing detritus. |
| Genre: | Article |
| ProdID: | 1001880 |
| Citation Author: | Keough, J. R.; Hagley, C. A.; Sierszen, M. |
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| Citation End Page: | 740 |
| Citation Issue: | 4 |
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| Citation Language: | English |
| Citation Larger Work Title: | Limnology and Oceanography |
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| Citation Number Of Pages: | 6 |
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| Citation Phsyical Description: | p. 734-740 |
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| Citation Search Results Text: | *d13C composition of primary producers and role of detritus in a freshwater coastal ecosystem; 1998; Article; Journal; Limnology and Oceanography; Keough, J. R.; Hagley, C. A.; Sierszen, M. |
| Citation Start Page: | 734 |
| Citation Volume: | 43 |
| Citation Year: | 1998 |
| Type: | citation/reference |
| Text: | *d13C composition of primary producers and role of detritus in a freshwater coastal ecosystem; 1998; Article; Journal; Limnology and Oceanography; Keough, J. R.; Hagley, C. A.; Sierszen, M. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Thu, 1 Jan 1998 00:00 -0600 |
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