Ecosystem Services Lesson, Part 2: Linking Ecosystems & Their Processes to What People Value and to Human Actions

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Ecologists have a long history of mapping and measuring attributes of nature (e.g., food webs, soil nutrients, genetic diversity), as well as a host of ecological processes (e.g., photosynthesis and plant growth, herbivory, hydrologic exchanges, as shown on the left side of the above figure); however, many of these qualities are not what people value from nature. For example, ecologists know that bacterial removal of excess nitrogen from water, called denitrification, is critical for the health of many coastal waters. People value productive fisheries and a chance to swim in clean water, but they may not value denitrification in the same way. The same gap between process and value is true for other scientific measurements including those associated with food web complexity, photosynthesis, genetic diversity, or a fully intact riparian corridor. These gaps make it hard to enact policies or to pay for management and restoration actions that ensure these processes and attributes of nature are healthy. However, people do value fisheries and clean water—both examples of ecosystem services—that depend on nutrient cycling, complex food webs, and photosynthesis.

Policy makers and managers need scientific measures because they provide insights into the types of management actions required. For example, knowing that the high carbon and low oxygen levels that characterize many wetlands make them ideal habitats for nitrogen-removing microbes, managers often restore wetlands along streams flowing to the coast. But to garner support for those restoration actions, there is a need for a “linking measure” between what scientists study and the ecosystem services that people care about. Such linking measures go by a variety of names: scientific or ecological outcome measures, socially relevant ecological output, benefit relevant indicators, or intermediate services. Nitrogen (N) concentration is one such indicator that is far more understandable to the public and to policy makers than denitrification. Additionally, N concentration can be used both in scientific predictions of denitrification rates and in fisheries predictions (i.e., the measurement of the amount of N in water can be linked to the underlying process we need to restore and what service we hope to gain—in this case, more fish).  Thus, this measurement is useful both to scientists and for ecosystem service valuation.

As introduced very briefly in the first lesson on valuation of ecosystem services, framing environmental problems in ecosystem service terms can be very helpful when trying to justify policy-related decisions and actions. And we learned in that lesson, ecosystem services can be valued both using market and non-market methods. In this second lesson, we focus on designing actionable science by exploring how to link ecological outputs from Lesson 1 to valued and socially relevant measures, which lead to policy actions. This process involves understanding linking measures and using causal analysis to help inform management and the public. In the third lesson, we focus on intrinsic and relational values of nature, which are much more difficult to link to policy actions except conservation.