An integer programming method for the design of multi-criteria multi-action conservation plans

Abstract

The design of conservation management plans is a crucial task for ensuring the preservation of ecosys- tems. A conservation plan is typically embodied by two types of decisions: in which areas of a given territory it will be implemented, and how actions against threats will be deployed across these areas. These decisions are usually guided by the resulting ecological benefit, their spatial effectiveness, and their implementation cost. In this paper, we propose a multi-criteria optimization framework, for modeling and solving a mixed integer programming characterization of a multi-action and multi-species conservation management de- sign problem. The optimization tool seeks for a management plan that maximizes ecological benefit and minimizes spatial fragmentation, simultaneously, while ensuring an implementation cost no greater than a given budget. For showing the effectiveness of the methodology, we consider a case study corresponding to a por- tion of the Mitchell river catchment, located in northern Australia, where 31 freshwater fish species are affected by four threats. The attained results show how the methodology exploits the trade-offs among the ecological, spatial and cost criteria, enabling decision-makers to explore and analyze a broad range of conservation plans. Selecting conservation plans in a more informed way allows to obtain the best outcomes from a strategic and operational point of view.