ABSTRACT
Summary Stability of windmill grass pastures in west central New South Wales was examined by measuring regeneration of two important grasses (Enteropogon acicularis and CMoris truncata) on two range sites grazed at three stocking rates (2.5, 3.7, and 4.9 sheep/ha) following 5 months of abusive grazing at 25 sheep/ha. Severe grazing reduced density and size of mature E. acicularis plants on both sites, particularly when heavy grazing (4.9 sheep/ha) was reintroduced during the period of pasture recovery. However, during the study E. acicularis density remained relatively stable because seedling cohorts compensated for plant losses in all treatments. Moderately grazed plots were considered the most demographically stable pastures because significantly more large plants (>9 cm) were present. In contrast, C. truncata populations were decimated by abusive grazing, and although they produced enormous cohorts subsequently, few plants survived one season. The combination of small plants and short life span renders C. truncata populations more susceptible to sudden catastrophe and therefore unstable. From a range science point of view, these findings mean that E. acicularis should be the focus of management programs, since the maintenance of this species should result in greater stability of pastoral resources.
