Population dynamics of the perennial rangeland shrubs Atriplex vesicaria, Maireana astrotricha and M. pyramidata under grazing, 1980-87

Over the 8-yr period moderate grazing did not affect the population dynamics of these shrubs. Density of A. vesicaria declined on both grazed and ungrazed transects, but that of Maireana spp. remained almost constant. Turnover rates of A. vesicaria were quite high for both grazed and ungrazed populations, but were extremely low for Maireana spp. Shrub size was the only population parameter significantly affected by grazing. Heights and diameters for both grazed and ungrazed populations declined during dry periods, a decline greater for grazed shrubs. After rain, however, grazed shrubs quickly returned to sizes similar to ungrazed. -from Authors