Incorporating biodiversity impacts in land use decisions.

We develop a framework for incorporating biodiversity impacts into land use optimization models. Using the countryside species–area relationship, six approaches to incorporating biodiversity are evaluated: constraint versus objective function, and with characterization factors, piecewise linear, or non-linear implementation. We also consider the underlying ethical assumptions of different options for biodiversity evaluation considering taxa and ecoregions. To explore the six approaches, we use a case study that considers both climate change mitigation and the biodiversity impact due to habitat loss. We find that the characterization factor approach underestimates biodiversity loss, while the piecewise linear approach somewhat overestimates. Utilizing two approaches: biodiversity protection as the objective, and biodiversity as a constraint allows the construction of a Pareto frontier for cost versus loss of species. In addition to minimum cost solutions and minimum biodiversity loss solutions, the integrated model allows to identify (1) solutions with improved outcomes, those better for biodiversity and with small changes on costs, (2) mechanisms the model uses to achieve the improved solutions, (3) trade-offs and (4) challenges. [Display omitted] • We show how biodiversity can be included in land use optimization models. • A case study combines climate mitigation and biodiversity protection. • We illustrate biodiversity as a constraint or in the objective function. • Piecewise linear performs better than the characterization factor approach. • A Pareto frontier shows cost versus species trade-off and improvement possibilities. [ABSTRACT FROM AUTHOR]