Atmospheric C02 enrichment is one of the few doubtless components of global change. Besides its influence on the climate system C02 affects the biosphere directly, because it is a key resource for photosynthesis. Consequently, "C02 fertilization" has been found many times to stimulate plant growth and agricultural yield, provided other resources were not limiting. However, many uncertainties still exist with respect to C02 responses of plants and ecosystems when life conditions are suboptimal, when mineral nutrients, water or light are limit~ ing, when plants compete for these resources and when interactions with other organisms come into play. Swiss biological C02 research has accumulated a substantial body of evidence to answer these questions.
This symposium will provide a first national synthesis. The meeting will be held under the auspices of the Swiss National Committee of IGBP, the Forum for Climale and Global Change (ProClim/SANW) and the NFP 31 and SPPU programs of the Swiss National Science Foundation, and will be organized locally by the Institute of Botany in Basel. Short ora! presentations will provide the essence of year~long research ranging from single plant studies under controlled conditions to investigations of whole ecosystems, from agricultural to natural vegetation and from high mountains to lowland tropical forests.