Optimal reserve site selection with multiple levels of protection

Most prior decision models for nature reserve-site selection have considered just two options for candidate sites: protected or not protected. In many reserve planning contexts this is an artificial and unrealistic limitation, as multiple categories of protection may be possible and desirable, especially if certain conservation elements such as rare species require special protection or management. In this paper we consider the implications of different levels of protection for species conservation and for the selection of reserve sites. New integer programming models are formulated for this problem of optimal site selection, and are presented in the context of a five-step procedure for identifying tradeoffs in the number of sites selected for each of multiple categories of protection. Results of a case study using data from Oregon are presented and compared to results from a previous study by Csuti et al.