Ecological Function Analysis: Incorporating Species Roles into Conservation

Effective conservation strategies must ensure that species remain not just extant, but able to maintain key roles in species interactions and in the maintenance of communities and ecosystems. Such ecological functions, however, have not been well incorporated into management or policy. We present a framework for quantifying ecological function that is complementary to population viability analysis (PVA) and that allows function to be integrated into strategic planning processes. Ecological function analysis (EFA) focuses on preventing secondary extinctions and maintaining ecosystem structure, biogeochemical processes, and resiliency. EFA can use a range of modeling approaches and, because most species interactions are relatively weak, EFA needs to be performed for relatively few species or functions, making it a realistic way to improve conservation management. Most current conservation strategies focus on preventing extinctions, but without explicit regard for the maintenance of sufficient abundance so that species can continue to interact with other species or impact the structure and function of their ecosystems. We develop the concepts and tools for ecological function analysis (EFA), to measure and quantify the roles that species play. EFA focuses on preventing cascading extinctions as well as maintaining ecosystem resiliency and critical biogeochemical processes. Because relatively few species have such strong ecosystem roles, EFA needs to be considered for manageable numbers of species and functions. EFA is flexible and adaptive, making it a critical complement to species-based approaches in improving conservation management.