The population dynamics of pastures, with particular reference to southern Australia.

In this chapter, a brief historical assessment will be given of the impact of development on grasslands in the agricultural areas of southern Australia, which are characterized by Mediterranean-type (south-western, southern) and temperate (southeastern) climates; these grasslands have a minimum mean annual rainfall of approximately 300 mm. Examples of the botanical changes that occurred in response to grazing, plant introduction and fertilizer application on the tablelands (predominantly non-arable, grazing) and slopes/plains (arable, farming) will be explored in relation to three conceptual models that have been used, worldwide, to describe and explain the interplay of climatic, edaphic and biotic factors on the dynamics of plant communities. Then, in a series of case-studies, pasture species/varieties that have been notably successful in Australian agriculture will be related to these models, and evaluated in terms of the processes and principles that have underpinned their competitive success. In a concluding section, past experience and experimentation will be considered in relation to the future integration of conservation and agriculture in Australian rural lands.