Reference benchmark sites

Benchmark values for basal area were collected from best-on-offer reference locations, including nature reserves and travelling stock routes near the Environmental Account Area. Given the highly modified nature of the surrounding landscape, fully pristine reference sites were not available. Sites were instead selected as the most intact locations available, with data collected from three sites per vegetation class. This approach was discussed and endorsed by the method author.

Accuracy of vegetation mapping

Vegetation mapping was undertaken by an experienced vegetation ecologist using a combination of field and remote sensing data. Some areas of the property have not been fully field-verified, and it is possible that additional surveys may identify minor inaccuracies over time. However, mapping uncertainty is not considered to have substantively impacted the accuracy of the findings, and we expect mapping to improve as the property is explored further.

Restoration objective for AU04

Field survey of this area identified a highly modified and degraded system dominated by introduced pasture species and African lovegrass. Restoring the area to native grassland was assessed as impractical given the difficulty of rebuilding appropriate soil conditions, persistent weed pressure, and challenges sourcing suitable grassland species. Changing climatic conditions in the Snowy Monaro region also mean woody vegetation is now better suited to this location. The area has therefore been designated for grassy woodland restoration, which is considered the more ecologically appropriate and viable long-term outcome.

Use of vegetation classes vs PCTs

Vegetation classes, rather than Plant Community Types, were used as the basis for sub-asset stratification. This simplifies the survey design process while remaining within the bounds of the method, with condition scores calculated by comparing site data against PCT-specific benchmarks.

Use of best-on-offer reference sites

Basal area benchmarks are not available in the NSW vegetation classification and condition assessment framework, so reference sites were selected from nature reserves and intact private land locations. The high degree of clearing across some vegetation sub-assets made identifying fully undisturbed reference sites difficult. The sites selected were therefore best-on-offer, meaning the most intact condition available. While there is potential for this to skew condition scores slightly higher, it is a recognised compromise that reflects the profound and widespread impact of European land use, changed fire regimes, invasive species, and climate change on the Australian landscape.