title: Net present biodiversity value and the design of biodiversity offsets.
abstract: There is an urgent need to develop sound theory and practice for biodiversity offsets to provide a better basis for offset multipliers, to improve accounting for time delays in offset repayments, and to develop a common framework for evaluating in-kind and out-of-kind offsets. Here, we apply concepts and measures from systematic conservation planning and financial accounting to provide a basis for determining equity across type (of biodiversity), space, and time. We introduce net present biodiversity value (NPBV) as a theoretical and practical measure for defining the offset required to achieve no-net-loss. For evaluating equity in type and space we use measures of biodiversity value from systematic conservation planning. Time discount rates are used to address risk of non-repayment, and loss of utility. We illustrate these concepts and measures with two examples of biodiversity impact-offset transactions. Considerable further work is required to understand the characteristics of these approaches.
authors.affiliation: Landcare Research, Hamilton, New Zealand. OvertonJ@LandcareResearch.co.nz
authors.forename: Jacob McC
authors.initials: JM
authors.lastname: Overton
authors.forename: R T Theo
authors.initials: RT
authors.lastname: Stephens
authors.forename: Simon
authors.initials: S
authors.lastname: Ferrier
mesh_terms: D044822:Biodiversity; D003247:Conservation of Natural Resources