A protocol for assessing applications to selectively clear vegetation in Australia

Broadscale clearance of native vegetation has been outlawed in most Australian states but there may be provisions for selective thinning to redress increases in woody vegetation (vegetation thickening) under existing legislation. A procedure described here for Queensland, Australia allows selective thinning in most vegetation types where vegetation thickening is demonstrated by changes in woody cover determined from time-series aerial photography. Before selective thinning would be allowed, thickening has to be demonstrated by a greater than 30% woody cover increase relative to the cover on the earliest aerial photograph. Retention thresholds prohibit the clearing of all mature trees and require that immature trees are retained according to prescribed densities. These thresholds are developed from field data and are specific to broad structural types of vegetation. Thinning is precluded from some vegetation types and the structural types of vegetation defining retention densities can be identified throughout Queensland with the assistance of a Regional Ecosystem mapping coverage. The procedure is compared with an alternative prepared for New South Wales. The Queensland procedure only allows selective thinning where vegetation thickening can be demonstrated and it is argued that the retention thresholds are designed to maintain the ecological integrity of the native vegetation. By contrast, the procedure for New South Wales has the potential for widespread application and will substantially undermine biodiversity values given that it allows a radical change of land-use including cropping. The Queensland procedure is equitable for applicants, provides landholders with a tenable management option to redress vegetation thickening, but is sufficiently prescriptive to preserve the character of the natural vegetation. The procedure forms the basis of an operational policy in Queensland.