Holocene history of vegetation and human action in the southern French Alps Landscape evolution in the Champsaur region (Hautes-Alpes, France): Palynological and dendroecological studies as a tool for understanding anthropogenic/natural processes interactions
by
Mona Court-Picon
Institut Méditerranéen d'Ecologie et de Paléoécologie (UMR CNRS 6116), Faculté des Sciences et Techniques Saint-Jérôme, Marseille, France et Laboratoire de Chrono-Ecologie (UMR CNRS 6565), Université de Franche-Comté
Coauthors: Alexandre BUTTLER (Laboratoire de Chrono-Ecologie, Université de Franche-Comté, Besançon, France), Frédéric GUIBAL (Institut Méditerranéen d'Ecologie et de Paléoécologie, Faculté des Sciences et Techniques Saint-Jérôme, Marseille, France), Valérie ANDRIEU-PONEL (Institut Méditerranéen d'Ecologie et de Paléoécologie, Faculté des Sciences et Techniques Saint-Jérôme, Marseille, France), Jean-Louis EDOUARD (Institut Méditerranéen d'Ecologie et de Paléoécologie, Faculté des Sciences et Techniques Saint-Jérôme, Marseille, France), Jacques-Louis de BEAULIEU ((Institut Méditerranéen d'Ecologie et de Paléoécologie, Faculté des Sciences et Techniques Saint-Jérôme, Marseille, France)

In an attempt of reconstructing palaeoenvironmental evolution throughout the last ten thousand years, especially by distinguishing human impact from natural trends since prehistoric times, an interdisciplinary project involving ecology, palynology, dendrochronology, archaeology and geomorphology has been undertaken with the collaboration of the environment managers of the Champsaur Plateau. Palaecological approach is in the continuity of palynological studies carried out in this region, which have outlined the general vegetation features.

The present work aims to study a small area at high spatial and temporal resolution. Our goal is to define accurately the variations of the type of land use since the first Neolithic forest clearances.

The research is divided into two parts: 1. Tree-ring chronologies analysis from subfossil timber will provide our study with an annual chronological framework. By comparing with regional master chronologies and other multiproxy-data (pollen, stable isotopes and geomorphology), regional climatic variability and human-induced changes in vegetation can be distinguished.

2. Cores were collected from several lakes and peat bogs situated in different vegetation structures and at various altitudes. Pollen analysis at high-resolution of these sequences particularly focus on palynological indicators of human impact on the landscape during the Holocene.

Two sites, Lauzons and Faudon lakes, have already been analysed. Lake Lauzons provides a palaeoenvironmental record which starts at the end of the Late-Glacial period. The diagram shows human influence on vegetation since the Final Bronze Age and an increase in human action at the top of the sequence. Pollen analysis of Lake Faudon reveals successive stages of deforestation, agricultural and pastoral systems during the Subatlantic. Plant macro-remains and micro-charcaoal analyses, 14C datings, and comparison with archaeological and historical records will precise these changes in vegetation evolution.

Date received: May 29, 2001

Copyright © 2001 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cahr-23.