The modelling highlighted the importance of the inherit productivity of the land type , land condition and tree basal area on the costs of management practice change . Land types with poor land condition and of low productivity provided the greatest opportunity for low cost sediment reductions .
Figure 23 shows the distribution of four dominant land types in the Burdekin region : Black basalt ( high productivity ), Goldfields ( low productivity ), Narrow – leaved ironbark on deeper soils ( Medium productivity ) and Red basalt ( High productivity ). The low productivity Goldfields country tends to dominate the high sediment generation areas of the Bowen , Upper Burdekin , Lower Burdekin and Don catchments . The soil can be described as brown loam over red clay duplex soil ( Whish et al . 2011 ).
Only the results for the dominant land type in the BBB catchment – the Goldfields land type - are presented here , but all results can be found in Star et al . ( 2013b ). The model runs scenarios for 20 climate windows , tree basal area , initial pasture condition , and grazing pressure . Pasture utilisation rates measure the grazing pressure , and represent the proportion of the total standing dry matter ( TSDM kg / ha ) remaining at the end of the growing season ( end of May ) that is to calculate the stocking rate for the following year .
Figure 23 . Distribution of four dominant land types in the Burdekin region . Source : Star et al . ( 2013 ).
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