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 cons ervation 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 classificati on is derived mainly from abiotic data and, in conjunction with new data on native vegetation cover, has allowed the first quantitative State-wide rev iew 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 numeri cal conservation priorities across extensive areas, and producing quantitat ive profiles Of priorities for the remaining native vegetation on private l and relative to that on other tenures. The same or similar approaches to de veloping the landscape classification and analysing biases and priorities a re feasible for many other jurisdictions or natural regions. We found that most of the 1486 landscapes in NSW are poorly reserved relative to an indic ative conservation target of 15% of the total area of each (the baseline ta rget in recent national planning for forest reserves). In the eastern 60% o f 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 urgen cy of conservation action to prevent conservation targets being compromised (or further compromised) by clearing of native vegetation. Mapping of prio rities shows large differences within and between natural regions and land tenures. More than 9% of private land is occupied by high-priority native v egetation and, across the whole State, about 85% of high-priority vegetatio n occurs on private land. (C) 2000 Elsevier Science Ltd. All rights reserve d.