Résumé
The impacts of raising atmospheric concentrations of carbon dioxide to twice ambient concentrations on the phenology, growth, and reproduction of 19 Mediterranean species are examined. Strategies used to extract intact monoliths from an old field are described. These monoliths were installed in growth chamers for a period of six months. The climatic conditions maintained in these chambers simulated external climatic conditions. Elevated CO sub(2) had a strong influence on the fruit set time of six of the species, and accelerated leaf and branch senescence in the majority of species examined. Grasses were found to have fewer leaves under elevated CO sub(2). Legumes exhibited greater branching at peak production in the chambers maintained under elevated CO sub(2). The higher CO sub(2) concentrations appeared to depress reproductive effort in grasses.