The biogeography of mediterranean invasions is of fundamental interest, as the preceding sections set out to show, and it is a major theme of this volume that studies of biological invasions have considerable application to the solution of major problems of land use in regions of mediterranean climate. As people, plants and animals have moved between the several regions of mediterranean climate problems in land use have arisen. Some plants have spread and invaded land used as range or for cropping or for human amenity. The ecology of these plants has been discussed in several preceding chapters but in this section they are discussed again in a more applied sense in relation to their control.

One potentially powerful way to control invasive organisms is to deliberately introduce highly selective natural enemies in a program of biological control. There have been several cases where such programs for invasive organisms in mediterranean regions have been successful, and sometimes spectacularly so, e.g. the introduction of the myxoma virus for rabbit control in southern Australia and the introduction of a chrysomelid beetle for control of St John's wort in California. These and other examples have been extensively reviewed elsewhere and will not be repeated here. In this section we include, however, a chapter on the introduction of dung beetles to southern Australia from France in a novel program to limit the breeding of native flies in the dung of introduced herbivores. Although there are dung beetles native to southern Australia they are relatively ineffective at reducing the rate of decomposition of dung pads from the domesticated herbivores introduced only 200 years ago.