The offset requirement may adjust the size or scope of a biodiversity offset relative to the measured biodiversity at a clearing site, to account for the risk that an offset will not be delivered, time lags and other differences in composition between the clearing and offset sites. Biodiversity indicators are used in offsets programmes to provide a representative picture of the environmental conditions at a site (Regan et al., The complexity of biodiversity means that there is “no universal measure or indicator of biodiversity or ecosystem state” (Failing and Gregory, 2003) so jurisdictions must make choices about the types of biodiversity that they will prioritise for measurement and inclusion in an indicator (ICCM and IUCN, 2012).