Economic/ecological tradeoffs among ecosystem services and biodiversity conservation

- An 11-species food web yields two ecosystem services: elk harvests and cattle grazing.
- Elk growth curves are used to derive a sustainability frontier.
- An economic optimum over harvests and grazing is constrained by the frontier.
- Conservation of biodiversity may place further constraints on the optimum.
- Real data from the Western United States illustrates the model's potential.

An integrated economic/ecological model is built to address tradeoffs between biodiversity conservation and two marketable rangeland ecosystem services: cattle grazing and elk hunting. The ecology is represented by an eleven species food web in which individual optimizing plants and animals engage in competitive and predator/prey relationships. The ecological model defines a steady-state set of sustainable grazing and hunting options, and for each option, biodiversity is measured using an index defined over the eleven species. In linking the ecology to the economics, social welfare depends on grazing profits and hunter net benefits. The problem can be stated as maximizing economic welfare over two ecosystem services, subject to their sustainable use and subject to a target level of biodiversity. A numerical application with economic and biological data from the Western United States is used to determine sustainable grazing and hunting options for alternative biodiversity levels, and to select the option that maximizes welfare.