A woodland-open forest landscape within the Brigalow Belt South bioregion of Queensland, Australia, was surveyed for soil organic carbon, soil bulk density and soil-surface fine-litter carbon. Soil carbon stocks to 30cm depth across 14 sites, spanning a range of soil and vegetation complexes, ranged from 10.7 to 61.8tC/ha, with an overall mean of 36.2tC/ha. Soil carbon stocks to 100cm depth ranged from 19.4 to 150.5tC/ha, with an overall mean of 72.9tC/ha. The standing stock of fine litter ranged from 1.0 to 7.0tC/ha, with a mean of 2.6tC/ha, and soil bulk density averaged 1.4g/cm3 at the soil surface, and 1.6g/cm3 at 1m depth. These results contribute to the currently sparse database of soil organic carbon and bulk density measurements in uncultivated soils within Australian open forests and woodlands.
The estimates of total soil organic carbon stock calculated to 30cm depth were further partitioned into resistant plant material (RPM), humus (HUM), and inert organic matter (IOM) pools using diffuse mid-infrared (MIR) analysis. Prediction of the HUM and RPM pools using the RothC soil carbon model agreed well with the MIR measurements, confirming the suitability of RothC for modelling soil organic carbon in these soils. Methods for quantifying soil organic carbon at landscape scales were also explored, and a new regression-based technique for estimating soil carbon stocks from simple field-measured soil attributes has been proposed.
The results of this study are discussed with particular reference to the difficulties encountered in the collection of the data, their limitations, and opportunities for the further development of methods for quantifying soil organic carbon at landscape scales.
Full-text publications from the Australian Rangelands Society (ARS) Biennial Conference Proceedings (1997-), Rangeland Journal (ARS/CSIRO; 1976-), plus videos and other resources about the rangelands of Australia.