Environmental risk in an age of biotic impoverishment.

The science underpinning biodiversity's importance to human well-being seems to be taken up little by environmental decision makers. Since the 1950s, ecological, evolutionary and environmental research has pointed to the importance of biodiversity as a significant factor influencing the stability and functioning of population, community, eco- and Earth-systems and the environmental services they provide. Despite its prominence and the tremendous contributions to our understanding of the natural world, this field of research, which we term 'bio-functional ecology', seems not to have had the impact it should. Biotic impoverishment, the loss of biodiversity across all scales and across all taxa, continues to worsen. We suggest that redirecting ecology's emphasis on ecological stability to a focus on environmental risk could help bring bio-functional ecology research more into the environmental arena. Rather than managing biodiversity as an agent of ecological stability, biodiversity could be managed as a natural capital asset in a portfolio of social, human, produced and financial capital assets. This would allow using portfolio theory to identify options for minimizing environmental risk while ensuring human well-being. In this essay, we argue that environmental risk more accurately captures people's motivation to preserve and manage biodiversity than does ecological stability. This redirection from stability to risk may provide greater clarity for decision makers and people in general as to why biodiversity is fundamentally linked to human well-being. In doing so, we can help curb the currently unabated spread of biotic impoverishment across the biosphere.