Dynamics of perennial grasses with sheep grazing in Acacia aneura woodlands in south-west Queensland

Increasing pasture utilisation reduced the total basal area of perennial grasses and resulted in major shifts in the occurrence of individual grass species. Aristida spp. were the main species under very heavy grazing. Variation in rainfall between years resulted in large changes in total basal area and in the occurrence of individual grass species. Long term wool production commensurate with maintenance of the vegetation may be maximized by 20 percent rather than higher levels of utilisation.