Using abiotic data for conservation assessments over extensive regions: quantitative methods applied across New South Wales, Australia

New South Wales (NSW) can be regarded as one of the more “data-rich” parts of the world but its detailed biological data sets, like others elsewhere, are localised. These data are therefore not useable over large geographical areas for consistent reviews of established protected areas or future conservation priorities. In this sense, the constraints of data are similar to those in other parts of the world, including global biodiversity hotspots. We describe here the development of a new classification of landscapes at a scale of 1:250,000 across the whole 802,000 km 2 of NSW. The classification is derived mainly from abiotic data and, in conjunction with new data on native vegetation cover, has allowed the first quantitative State-wide review of protected areas and future priorities at a scale approaching that of decisions about land use. We also describe methods for measuring biases in the coverage of reserves in relation to land use potential, mapping numerical conservation priorities across extensive areas, and producing quantitative profiles of priorities for the remaining native vegetation on private land relative to that on other tenures. The same or similar approaches to developing the landscape classification and analysing biases and priorities are feasible for many other jurisdictions or natural regions. We found that most of the 1486 landscapes in NSW are poorly reserved relative to an indicative conservation target of 15% of the total area of each (the baseline target in recent national planning for forest reserves). In the eastern 60% of the State, gaps in the reserve system are related to the concentration of reserves on land with high ruggedness and low potential for intensive land use. We measured the relative priority of landscapes to indicate the urgency of conservation action to prevent conservation targets being compromised (or further compromised) by clearing of native vegetation. Mapping of priorities shows large differences within and between natural regions and land tenures. More than 9% of private land is occupied by high-priority native vegetation and, across the whole State, about 85% of high-priority vegetation occurs on private land.