|
|
 |
|
|
| |
Communication at the NABS Annual meeting, Keystone, 2000
(105) THE IMPORTANCE OF BENTHIC ALGAE TO AQUATIC FOOD WEBS IN AUSTRALIAN STREAMS AND RIVERS.
S.E. Bunn1, P.M. Davies2, and J.W. Udy1. 1Cooperative Research Centre for Freshwater Ecology, Griffith University, Nathan, Queensland, 4111, Australia, 2Department of Zoology, The University of Western Australia, Nedlands, Western Australia 6907
Only a small fraction of the total carbon present in a stream or river is likely to enter the aquatic food web: not all is of sufficient quality or is truly available for consumers. A fundamental consideration to understanding food webs is to first identify the source or sources of organic carbon that are assimilated by consumers. Stable isotope analysis has proved to be an effective tool in the study of food webs in aquatic ecosystems where there are often marked differences in the signatures of primary sources. However, its application to the study of stream food webs has often been confounded by considerable variation in the carbon isotope signatures of algae, and overlap with terrestrial plant values. Recent studies of stream and river food webs across several biomes in Australia suggest that a significant component of the variation in carbon isotope signatures of benthic algae can be explained by variation in GPP. Furthermore, stable carbon isotope signatures of consumers appear to track algal signatures whenever the latter are 13C-enriched. These data demonstrate the utility of stable carbon isotope analysis in stream and river food web studies and highlight the important role of benthic algae in some systems.
Presented at 11:00 AM on Tuesday, May 30, 2000 in Food Webs and Communities II
|
|
|
|
|
|
|
