Ecological Effects of Tree Clearing

Tree clearing was practised for greater beef production and hence monetary gains from grazing systems of central Queensland (given the high rates of clearing even recently (577, 000 ha/yr during 1999-2001). The sustainability of cleared pasture systems over the long-term is questioned.Three major types of tree communities i.e. Eucalyptus populnea F. Muell., E. melanophloia F. Muell. and Acacia harpophylla F. Muell. ex. Benth. were selected on one property in central Queensland to quantify the impacts of clearing on pasture production and composition, and soil properties. The impacts were measured over time-since-clearing (recent (5 years), medium (11-13years) and old (30 years)) in unreplicated cleared pastures in comparison to their replicated uncleared/intact woodland pastures of each tree community. Pasture yield was not sustainable over the long-term. Moreover, the changes in some soil properties underscored the associated risks and changes in ecosystem functions due to clearing. The overall effect of clearing in terms of pasture and litter production, and major soil parameters were analysed using multivariate analyses.