Citation Information: Ardron, J.A., Possingham, H.P., and Klein, C.J. (eds). 2010. Marxan Good Practices Handbook, Version 2. Pacific Marine Analysis and Research Association, Victoria, BC, Canada. 165 pages. http://pacmara.org/
Abstract: Marxan is software that delivers decision support for reserve system design. Marxan was initially designed to solve a particular class of reserve design problems known as the minimum set problem (see Box 1.1) where the goal is to achieve some minimum representation of biodiversity features for the smallest possible cost. Marxan helps users to determine the possible contribution of individual areas and whole networks towards meeting their objectives. Users may use Marxan to explore and propose possible network configurations, to facilitate collaborative network design, or to guide their own land acquisition / marine zoning. Marxan is not designed to act as a stand‐alone reserve design solution. Its effectiveness is dependent upon the involvement of people, the adoption of sound ecological principles, the establishment of scientifically defensible conservation goals and targets and the construction of spatial datasets. Marxan should be used as part of a systematic conservation planning process (outlined in this chapter) and in collaboration with other forms of knowledge. These other forms of knowledge are essential to the refinement of Marxan inputs, the interpretation of Marxan outcomes and the precise placement of final reserve boundaries. Because it seeks spatially efficient solutions, based on a defined problem, Marxan represents a significant step forward from earlier approaches of scoring sites. Nonetheless, there is a significant amount of uncertainty in selecting sites, which is but one aspect of systematic conservation planning, the final step of which is monitoring to evaluate whether the sites make meaningful contributions to the network.