This vegetation map for the Border Rivers-Gwydir Catchment Management Authority (CMA) area, Northern NSW, was upgraded in 2009 by EcoLogical Aust. This included adding new spatial data targeting unmapped ‘gaps’, by removing areas of non-woody vegetation previously mapped as woody, and by further refining the regional vegetation community (RVC) classification. The labelling of ‘undetermined’ types is made more consistent, and a final spatial verification of the distribution of each RVC is undertaken.
Integration of the four new layers adds about 115,000 ha of ‘woody’ RVCs and 200,000 ha of either non-woody RVCs or non-vegetation to the vegetation map, while elimination of ‘non-woody’ areas of woody RVCs converts some 145,000 ha to either non-woody vegetation RVCs or non-vegetation. The net result of the review is a reduction in the extent of mapped woody RVCs by about 30,000 ha, an increase in mapped non-woody RVCs by 80,000 ha, and an increase in mapped non-vegetation (mainly cropping) by about 120,000 ha.
The consistency of labelling of undetermined types in the layer is improved by replacing previous labels –'undetermined veg’, ‘undetermined non-veg’ and ‘undetermined’ with more definitive categories – ‘undetermined woody veg’, ‘undetermined non-woody veg’ and ‘undetermined non veg’.
A total of about 1,053,000 ha of the map incurred a change of RVC as a result of RVC review, mainly as a result of review of grassland mapping, specifically RVCs 26 – 28, and grassy box types, including RVC 19 (White Cypress Pine -
Silver-leaved Ironbark grassy woodland, Nandewar) and RVC 44 (White Box - pine - Silver-leaved Ironbark shrubby open forests, Brigalow Belt South and Nandewar).
While data gaps remain in the vegetation layer, particularly in the north-east of the catchment, their extent has diminished as a result of integration of new data, so that the overall mapped coverage of RVCs has increased in the BRG, and the spatial distribution of mapped RVCs has also improved. This provides more certainty in spatial outputs arising from interrogation of spatial vegetation data, for example ‘high conservation value’ surfaces. However, the inherent problem of quality of baseline composite API data upon which the RVC surface is based continues to be recognised, and opportunities to continue to improve the vegetation map through further gap filling and field verification should be taken.
Note this dataset supersedes the BRG component of the existing vegetation dataset called "Namoi and Border Rivers Gwydir Catchments composite vegetation map (2008) - VIS_ID 3842" dataset.
Eco Logical Australia (2009). Upgrade of Vegetation Mapping in the Border Rivers-Gwydir Catchment. A Product for the High Conservation Value Project. EcoLogical Australia 11/10/2009 Project# 09COFGIS-0002