Understanding the structure and functioning of ecosystems requires first to characterize and quantify the main sources of organic matter that support animal communities and food webs, and to identify trophic relationships within organisms. All along their life cycle, organisms integrate some molecules or elements that bring information, by themselves or through the ratios of several of them, about either consumer trophic ressources or the habitats they exploit for feeding. Analyzing tracers in various tissues allows to address the temporal variability of the trophic resources. However, when used alone, these ecological tracers often give data which are difficult to interpret, but several tracers used together brings much more power to decipher consumer resources.
LIENSs have the expertises and analytical facilities for 3 ecological tracers : stable isotopes, fatty acids and trace elements. A workgroup dedicated to the use of ecological tracers has been built to share common issues and enhance their use within the laboratory.
Four topics are addressed within this workgroup :
1. Technical improvement of methods and tools
2. Use of one or several tracers to various animal models
3. Experimental use of tracers to complement in situ studies
4. Food web and tracers