Understanding the role of different capitals in the resilient provision of ecosystem services
Conceptual diagram of ecosystem service provision in an agricultural landscape. Solid lines inside the circle represent flows of material or information within a landscape. Dotted lines represent flows from one landscape to another.
Overview
Despite increasing recognition that ecosystem services (ES) are co-produced by natural and human drivers, most management-focused ES models continue to either overlook, or to overemphasize, the role of human drivers, such as technology, management, or infrastructure, in the provision of ES. This is largely due to lack of information about the interplay between natural and human capitals in the provision of ecosystem services.
Project Lead: Jesse Rieb
Collaborators: E Bennett, Brian Robinson
Approach 1
Human drivers are misused in ES models in part due to a lack of understanding of the fundamental shapes of the relationships between human drivers and the provision of ES. Information about the relative roles of both natural and human capital in ES outcomes is essential to fully understanding the importance of natural capital to human well-being. In turn, this information can help decision-makers make better decisions about whether to provide ES through protection of natural capital or use of human drivers. In this project, we use an empirical, data-driven approach to explore the relationships between natural capital, human drivers, and the provision of three ES: crop production, water purification, and nature recreation.
Illustration of three general propositions about co-produced ES. The upper row shows ES provision (grey contour lines, thicker lines indicate greater ES provision) as a function of both a “focal capital” that is actively being managed or monitored and an “other capital” that is also influencing ES provision. The lower row reframes the upper row as two-dimensional cross-sections, showing ES provision or its marginal change as a function of one of the two capitals. Panel a illustrates variation in ES provision as a result of changes in a non-focal capital (long arrow). Panel b illustrates how the change in ES provision as the result of a small increase in the focal capital (short arrows) changes relative to the amount of the focal capital. Panel c illustrates how the change in ES provision as the result of a small increase in the focal capital (short arrows) changes relative to the amount of the other capital. The exact shape of these relationships is determined by the relationship between capitals and ES provision (in this figure, partial substitutability between capitals), but the propositions are likely to be valid across a range of ES–capital relationships.
Approach 2
Understanding the capacity for, and limitations of, human-derived capitals to enhance or substitute for natural capital is important for environmental decision-making, especially for decisions about when to promote conservation of natural capital to provide ecosystem services and when to employ technological alternatives. From the perspective of long-term sustainable ecosystem management, such decisions are further complicated by dynamics and interactions between different types of capital. In this project, we’ve built a simple simulation model to compare how different assumptions around temporal dynamics and interactions between natural and human-derived capitals affect long-term outcomes of different management choices on ES provision. With an understanding of the dynamics and interactions of natural and human-derived capitals, it is possible to determine general long-term ES management strategies that are more likely to produce the desired benefits.
Illustration of modelling approach for two scenarios, each representing a management decision to use certain amounts of natural and human-derived capital to produce an ES. Layers in the figure represent a theoretical “decision space,” defined by the amounts of natural (x-axis) and human-derived capitals (y-axis) used to provide an ES. (a) Point (i,j) has an initial value of 0 units of natural capital (N) and 1 unit of human-derived capital (H), and point (x,y) has an initial value of 2 units of N and 0 units of H. ES provision is calculated for each point at each time step (light green = high ES provision, dark green = low ES provision). (b) The amount of each type of capital changes over time for each pixel, as determined by the dynamics included in the model. For each pixel, the amount of ES provision is added across all time steps to calculate cumulative ES provision. (c) This cumulative provision is subtracted from what would be expected if the amounts of capitals were not changing to determine the difference from the static model (red = more ES provision than expected in a static scenario, blue = less ES provision). For our evaluation, this process was repeated for all combinations of values of natural and human-derived capital from 0 to 100 units (10201 total pixels) and run for 100 time-steps.