Our knowledge of the functional characteristics of the plants of mediterranean-cl imate regions has increased greatly in the past decade. In recent times the possibility of large-scale util ization of biomass for energy from these regions has been proposed. In order to assess the feasibil ity of these proposals we must consider the productive structure of these plant communities and how they vary through time and space. This symposium was an attempt to examine our recently acquired basic knowledge of the environmental I imitations on the productivity of Mediterranean plant communities in relation to the consequences of the possible util ization of these communities for energy and chemicals. Specifically in this book we examine the mechanisms by which plants of mediterranean-cl imate regions maintain their productive capacity under the prevail ing conditions of summer draught and winter cold. We consider the characteristics of leaves, their history, morphology and plasticity. Evergreen sclerophyll leaves are common to the dominant plants of all mediterranean-cl imate regions and thus they have significance in terms of enhancing carbon gain and water-use efficiency as well as ensuring survival under the prevail ing cl imatic conditions.