The central theme of this text is that the introduction of agricultural and pastoral systems in Australia's temperate grazing lands has often created dynamic and sustaining ecosystems. The author argues that while these ecosystems are not native, and while they are not problem-free, they have made an immense contribution to the building of the country - largely in terms of increased soil fertility. This has been done by adding trace elements, superphosphate and legumes, thereby developing a new ecosystem, probably just as self-sustaining as the one it replaced.