Benefits or losses from clearing trees to develop pastures in central Queensland, Australia?

Abstract

Clearing trees to develop land for exotic pastures that enhance pasture production and hence the financial gains, is an important issue in Queensland. Gains from clearing woodlands are questioned. Three tree communities i.e. Acacia harpophylla, Eucalyptus melanophloia and Eucalyptus populnea were selected at three different ages of clearing i.e. 5 yr, 11-13 yr and 33 yr to collect the data on pasture production, soil properties (biological and physicochemical), litter production and nutrient recycling and pasture plant diversity over 2-3 year period of the study. The net economic gains from clearing in terms of pasture production were compared to uncleared pastures and assessed against the tradeoffs of ecological services. The increase in pasture production post-clearing was not consistent with age of clearing. A bioeconomic model, applied to predict pasture production over the 50 years of time of clearing, though suggested economic benefits, however, it is difficult to predict how the loss in ecosystem functions in cleared pastures (> 30 years of clearing), by implication, affect pasture yield over time.