The pasture dynamics and management of two rangeland communities in the Victoria River District of the Northern Territory.

Abstract

The use of destocking as a means of promoting pasture recovery was evaluated on two important rangeland types of the semi-arid tropics of north west Australia. Recovery on eroded calcareous red soils was substantial within five years. Standing biomass and species composition, particularly the contribution of the major forage grass Enneapogon spp., was then similar to areas in good condition. However, an exotic shrub, Calotropls procera, invaded the area during the study. Grazing limited its increase to 200 bushes ha-1 compared to unstocked areas where it increased to 1,000 bushes ha-1. Destocking had no effect on cracking clay soils in good condition, dominated by Chrysopogon fallax and Iseilema fragile. An index based on similarity measures of herbage standing biomass, followed closely the course of recovery of the eroded calcareous soil during the period. There is a need for range condition assessment and the development and application of appropriate pasture management strategies for the whole district.