Avocet carbon budget

The carbon estimates outlined below were taken from “Avocet”, a grazing property, located approximately 32 km south of Emerald in Central Queensland. The property has a total area of 4274 ha, of which about 1533 ha (36%) has been cleared for grazing, and the remainder is uncleared natural bushland. Cattle are grazed in both cleared and uncleared areas. “Avocet” is located within the Brigalow Belt Bioregion, and includes vegetation categorised in 18 Regional Ecosystems. As the property included such a wide range of Regional Ecosystems (REs) it was decided to sample only eight of the REs, (marked in bold in Table 1) and to apply the information from these sites to the other REs. At each RE one general area (site) was selected to be representative of the vegetation. Trees were measured in 200m² rectangular plots called transects. 30 transects were laid out at each site. Each transect was 50 metres long and 4 metres wide, and all were laid in a north-south direction. All trees were measured in the first three transects. Dead trees, if encountered were included in the measurements. In the remaining transects, trees were measured until thirty trees of each major tree type had been measured and then, only the number of trees was counted in each transect. All trees and bushes over 1.8 metres weremeasured. It was assumed that trees and bushes lower than this height would be susceptible to fire and may have perished in the landscape. In some REs one site was not sufficient to represent the variation in vegetation that occurred and in such cases more that one site was sampled. The stem circumference of each tree selected was measured at a height of 30 cm above the ground. From this measurement, the tree biomass was calculated using previously developed equations, which relate stem circumference, or in some cases, stem diameter, to total above-ground biomass.