The Biology Of Mediterranean Type Ecosystems

The world's mediterranean-type climate regions (including areas within the Mediterranean, South Africa, Australia, California, and Chile) have long been of interest to biologists by virtue of their extraordinary biodiversity and the appearance of evolutionary convergence between these disparate regions. These regions contain many rare and endemic species. Their mild climate makes them appealing places to live and visit and this has resulted in numerous threats to the species and communities that occupy them. Threats include a wide range of factors such as habitat loss due to development and agriculture, disturbance, invasive species, and climate change. As a result, they continue to attract far more attention than their limited geographic area might suggest. This book provides a concise but comprehensive introduction to mediterranean-type ecosystems. It is an accessible text which provides an authoritative overview of the topic. As with other books in the Biology of Habitats Series, the emphasis in this book is on the organisms that dominate these regions although their management, conservation, and restoration are also considered.

Human activities are causing species extinctions at a rate and magnitude rivaling those of past geologic extinction events. Exploring mediterranean-type ecosystems - the Mediterranean Basin, California, Chile, Australia, and South Africa - this volume addresses the question whether biological diversity plays a significant role in the functioning of natural ecosystems, and to what extent that diversity can be reduced without causing system malfunction. Comparative studies in ecosystems that are similar in certain respects, but differ in others, offer considerable scope for gaining new insights into the links between biodiversity and ecosystem functioning.

No other disjunct pieces of land present such striking similarities as the widely sepa 1 rated regions with a mediterranean type of climate, that is, the territories fringing the Mediterranean Sea, California, Central Chile and the southernmost strips of South Mrica and Australia. Similarities are not confined to climatic trends, but are also reflected in the physiognomy ofthe vegetation, in land use patterns and frequently in the general appearance of the landscape. The very close similarities in agricultural practices and sometimes also in rural settlements are dependent on the climatic and edaphic analogies, as well as on a certain commonality in qdtural history. This is certainly true for the Mediterranean Sea basin which in many ways represents a sort of ecological-cultural unit; this is also valid for CaUfornia and Chile, which were both settled by Spaniards and which showed periods of vigorous commercial and cultural interchanges as during the California gold rush. One other general feature is the massive interchange of cultivated and weed species of plants that has occurred between the five areas of the world that have a mediterranean-type climate, with the Mediterranean basin region itself as a major source. In spite of their limited territorial extension, probably no other parts of the world have played a more fundamental role in the history of mankind. Phoenician, Etruscan, Hellenic, Jewish, Roman, Christian andArab civilizations, among others,haveshapedmanyofman's present attitudes, including his position and perception vis-a-vis nature.

Regions with Mediterranean-type climates include parts of California, South America, Australia, and of course, Europe. The effect of global climate change on these heavily populated areas will have major social and political ramifications. This volume addresses issues in these areas, from processes at the leaf level to the individual, ecosystem, and landscape levels. This book will serve to raise awareness on the significance of these types of ecosystems, and on their sensitivity to the threat that global change represents.

The Sixth International Conference on Mediterranean Climate ecosystems was held at Maleme (Crete), Greece, from September 23 to September 27, 1991. This conference had as its theme 'Plant-Animal Interactions in Mediterranean-type Ecosystems'. Most of the papers presented to that meeting have already been published (see Thanos, C.A. ed., 1992, Proceedings of the VI International Conference on Mediterranean Climate Ecosystems, Athens, 389 pp.). These 57 papers were all necessarily short. But the theme of plant-animal interactions was considered by the Organizing Committee to be so important to a fundamental understanding of the ecology of Mediterranean-climate ecosystems and to an enhanced management ·of those systems that various international research scientists were invited to prepare longer contributions on major aspects of the overall theme. The Book that follows represents the result of those invitations. All five regions of Mediterranean climate are represented - Chile, California, southern Australia and the Cape Province of South Africa, as well as the Mediterranean Basin itself.

The theory of ecological convergence underlies the biogeographers' maps of world biome-types. It also determines the degree to which ecological principles, derived from research on particular populations, communities or ecosystems, are generally valid, and hence also to what extent resource management principles are general. To quote Di Castri and Mooney (1973): "In effect, in order to assess the transfer of technology, it is essential to know to what extent information acquired from studying one particular ecosystem is applicable to another ecosystem of the same type but situated in a different location. " The five relatively small, isolated, mediterranean-climate zones of the earth, each with its distinct fauna and flora, have provided the ideal testing grounds for this theory. A heritage of precisely focused ecosystems research has resulted, beginning with the international comparative analyses conducted by Specht (l969a, b) but with antecedents in earlier studies in South Australia (Specht and Rayson 1957, Specht 1973). Cody and Mooney (1978) reviewed the information available at the time for the four zones excepting Australia and concluded that the arrays of strategy-types to be found among the different biotas were so similar that they could be explained only in terms of the convergence hypothesis; nevertheless, evident differences in community organization and dynamics, especially phenol ogy, required closer study of resource availability and resource-use patterns to better explain relations between form and function overall, and to assess the degree of convergence at higher levels of organization than the population.

G.P. Stamou describes the adaptive strategies that allow arthropods to cope with the severity of Mediterranean environments. After an introduction to the structure and function of Mediterranean-type ecosystems, ecophysiological adaptations to water stress and varying temperature are considered. Further, activity patterns and life cycle tactics are discussed in relation to the peculiarity of Mediterranean environments. Phenological patterns and population dynamics as well as community structures are also presented. The volume ends with a synthesis of life history tactics.

Human impact on natural landscapes through urbanization and agricultural expansion are becoming more and more dramatic and are the cause of serious environmental problems. This volume examines the effect of landscape disturbance on plant and animal diversity in the five mediterranean-climate regions of the world. It begins with three introductory chapters broadly reviewing the issues of landscape degradation. Further contributions describe regional land use conflicts in each of the five regions. Landscape disturbance and plant diversity, and landscape disturbance and animal diversity are treated in separate chapters. Four contributions deal with demography and ecophysiology in vegetation succession following disturbance. The volume closes with a consideration of the future addressing aspects of environmental politics.