This paper seeks to clarify how valuation should be conducted to answer specific environmental policy questions. In particular, it looks at how valuation should be used to examine four distinct aspects of the value of ecosystems: 1) Determining the value of the total flow of benefits from ecosystems
2) Determining the net benefits of interventions that alter ecosystem conditions: 3) Examining how the costs and benefits of ecosystems are distributed
and, 4) Identifying potential financing sources for conservation. These four approaches are closely linked, and build on each other. They represent four different ways to look at similar data regarding the value of an ecosystem: its total value, or contribution to society, the change in this value if a conservation action is undertaken, how this change affects different stakeholders. Each of these approaches to valuation uses similar data, yet in very different ways, that is, sometimes at a subset, sometimes looking at a snapshot, and sometimes looking at changes over time. Each approach has its uses and its limitations.