Effect of drought and high summer rainfall on biomass and comsumption of grazed pastures in western New South Wales.

Abstract

The biomass and composition of grazed pastures near Menindee, in westem New South wales, were estimated over a range of seasonal condilions between 1980 and 1985. Differences in biomass and composition of pastures grazed separately by kangaroos and by a mixture of sheep and kangaroos were minor. Pasture biomass ranged from 7 kgha during a drought to 1,100 kgha following high summer rainfall. Overall, biomass average 374 kgha with a slandard deviation among years of 302 kgha. Pasture biomass fluctuated markedly among calendar seasons and years in response to erratic rainfall and grazing. I-Iigh summer rainfall triggered a switch in pasture dominatnace from annuals to shoa-lived perennials.