Studies of Central Australian Semidesert Rangelands. I. Range Condition and the Biomass Dynamics of the Herbage Layer and Litter.

Abstract

Following a sequence of years of above-average rainfall, standing biomass, rates of production and quantities of litter were high in the ground storey of three central Australian rangeland plant communities. Standing biomass was of the order of 4000 kg ha^-1 in Astrebla grasslands, 2600 kg ha^-1 in open woodlands and 1300 kg ha^-1 in Acacia shrublands, and litter biomass was c. 1300 kg ha^-1, 1600 kg ha^-1 and 4000 kg ha^-1 respectively. Levels of biomass and production rates were comparable with those of some semiarid and temperate sown pastures in average seasons, but they appeared to have reached their natural limit.

Total standing biomass, production rates, species diversity, litter biomass and decomposition rates were not correlated with range condition assessments of the experimental sites. Species frequency was the only characteristic measured which was related to range condition other than botanical composition, the basis of site selection.