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."

The emergence of landscape ecology during the 1980s represents an impor tant maturation of ecological theory. Once enamored with the conceptual beauty of well-balanced, homogeneous ecosystems, ecologists now assert that much of the essence of ecological systems lies in their lumpiness. Patches with differing properties and behaviors lie strewn across the land scape, products of the complex interactions of climate, disturbance, and biotic processes. It is the collective behavior of this patchwork of eco systems that drives pattern and process of the landscape. is not an end point This realization of the importance of patch dynamics in itself, however. Rather, it is a passage to a new conceptual framework, the internal workings of which remain obscure. The next tier of questions includes: What are the fundamental pieces that compose a landscape? How are these pieces bounded? To what extent do these boundaries influence communication and interaction among patches of the landscape? Will con sideration of the interactions among landscape elements help us to under stand the workings of landscapes? At the core of these questions lies the notion of the ecotone, a term with a lineage that even predates ecosystem. Late in the nineteenth century, F. E. Clements realized that the transition zones between plant communi ties had properties distinct from either of the adjacent communities. Not until the emergence of patch dynamics theory, however, has central signif icance of the ecotone concept become apparent."