Bimodality in stable isotope composition facilitatesthe tracing of carbon transfer from macrophytes to highertrophic levels
2013 (English)In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, no 710, 205-218 p.Article in journal, Editorial material (Refereed) Published
Even though the suitability of macrophytesto act as a carbon source to food webs hasbeen questioned by some studies, some others indicate that macrophyte-derived carbon may play an importantrole in the trophic transfer of organic matter in thefood web of shallow lakes. To evaluate the importanceof macrophytes to food webs, we collected primaryproducers—macrophytes and periphyton—and consumersfrom 19 South American shallow lakes andanalyzed their carbon stable isotopes composition(d13C). Despite the diversity of inorganic carbonsources available in our study lakes, the macrophytes’d13C signatures showed a clear bimodal distribution:13C-depleted and 13C-enriched, averaging at -27.2 and -13.5%, respectively. We argue that the use ofeither CO2 or HCO3- by the macrophytes largelycaused the bimodal pattern in d13C signals. Thecontribution of carbon from macrophytes to the lake’sfood webs was not straightforward in most of the lakesbecause the macrophytes’ isotopic composition wasquite similar to the isotopic composition of periphyton,phytoplankton, and terrestrial carbon. However,in some lakes where the macrophytes had a distinctisotopic signature, our data suggest that macrophytescan represent an important carbon source to shallowlake food webs.
Place, publisher, year, edition, pages
2013. no 710, 205-218 p.
IdentifiersURN: urn:nbn:se:uu:diva-281104DOI: 10.1007/s10750-012-1366-8OAI: oai:DiVA.org:uu-281104DiVA: diva2:912812