Along with providing more realistic views of ecosystem service provision and use, these flow maps can also enable improved value transfer. A better understanding of the relative strength of flow can identify regions more likely to provide higher or lower levels of value (Boyd and Wainger 2003). Indeed the flow of benefits is the only quantity that relates supply and demand and is a natural candidate for a quantitative statement of value. In order for a flow of benefit to exist, a potential for provision must coexist with a need for use; the marginal value is determined by the “difference.
