HUMAN IMPACT AND CLIMATE OVER THE LAST 2000 YEARS IN THE ENGADIN (SWITZERLAND) AS RECORDED BY CHIRONOMIDS (NON-BITING MIDGES)

Chironomids have been shown as good indicators of temperature changes through the Little Ice Age and the Holocene in various regions of Scandinavia, Canada and Switzerland. Comparisons between chironomid-inferred temperatures and century-long instrumental data have indicated that this method is accurate, within the sample specific error of the inferences (Larocque & Hall, in press). Human impact can alter this good relationship between climate and chironomids (Heiri et al. 2002), although chironomids seem be insensitive to damming in Canada (ref). Switzerland has a long history of human activities (e.g. logging, grazing, farming) in the Alps. This study tries to disentangle the effects of human impact and climate on the chironomid communities of a deep lake (Silverplanersee) located in the Engadin area of Switzerland. A 50-lake training set is being developed in the area to allow temperature reconstruction using chironomids. Limnological studies were being held for the last 20 years in this lake, allowing comparison between contemporary results and paleoecological results. This project is part of a multi-proxy program using also diatoms and pollen as indicators of climate and human impact. It is then an overarching project linking both HITE (Human Impacts on terrestrial Environments) and LIMPACS, programs under the umbrella of PAGES Focus 5: Past ecosystems and human-environment interactions.