Elements of the original tree cover remain in most grazed landscapes in eastern Australia, ranging from scattered trees to dense woodlands. However, we do not fully understand the role of these trees in grazing systems. Evidence is accumulating that both environmental and economic benefits can be derived from retaining native trees and shrubs in grazing lands. A variety of ecological processes might explain these trends and here we summarise some of these processes. Native trees and shrubs provide shade and shelter for livestock and have a demonstrated value in livestock production. Trees and shrubs can have both positive and negative effects on soil water balance and their overall effect on water availability in grazing systems is, as yet, unresolved.

There is however, growing evidence that soils around trees have elevated organic matter and nutrient status and although the magnitude of this pattern varies between species it appears to be consistent and to be independent of animal camping. In addition, the presence of trees influences the composition of swards as well as how they grow, with a larger proportion of more palatable grass species beneath tree cover. There is now good evidence that removal of tree cover, although appearing to provide a short-term production benefit, has negative effects in the long-term. We suggest that the influence of trees on soils, pastures and livestock production need to be considered to devise a desirable range of vegetation densities and configurations to achieve a balanced and productive grazing industry.