Effects of land-use changes in the Alps on exchange processes (CO2, H2O) in grassland ecosystems

Results of the EU framework IV project "ECOMONT" (Ecological Effects of Lan d-use Changes on European Terrestrial Mountain Ecosystems) are presented. C anopy structure, energy balance and CO, gas exchange of two differently man aged areas (hay meadow, pasture), an abandoned area and a natural wetland i n the Monte Bondone (Italy) research area were compared. Results show that land-use induced changes in the vegetation structure (accumulation of dead plant material within the canopy) decisively influence the ecosystem proces ses. Abandonment leads to a decrease in soil respiration and canopy photosy nthesis, as well as to a decrease in evapotranspiration and water use effic iency.