Impacts des changements climatiques sur le comportement de la végétation dans le fossé Rhénan

Abstract

Impacts of climate change on the behaviour of vegetation in the Rhine valley Following results of regional climatic models, the regional impact of climate change in the southern Rhine valley in Central Europe will result in hotter and dryer summer seasons. Because this region is already the warmest and dryest area in Germany, it seems to be favourite to perform interdisciplinary research on climate change impacts. Which modifications in plant water supply will result in which yield changes and in which carbon stock changes in relation to the sense of the protocol of Kyoto? The international working group defined these questions to be a research task in finding answers. Test plants are wheat (France), pine (Germany) and corn (Switzerland). We have different water use efficiencies (C3-and C4-plants). With new research methods, jointly applying the individual specific contributions of the four partners it will be possible to explain the relations between the atmospheric carbon supply and the biomass production and its variations in time and related to the weather. The project consists in simultaneous measurements at the three sites combined with isotopic analyses in the laboratory and joint data analyses. Micrometeorological flux and storage term estimates of CO 2 are completed with physiological transpiration measurements by means of 13 C and 18 O tracers and porometric measurements. Then budget calculations are required to estimate the storage capacity of the ecosystems under investigation. This will enable the three states involved in the project to present more precise capacity calculations in carbon stock of the vegetation and carbon exchange with the atmosphere.