Servicesheds

Servicesheds are a new concept that helps us map where people get specific benefits from nature. Each benefit, like tourism, climate regulation, flood protection, erosion control, clean drinking water, provision of fish and so on, comes from a specific part of a landscape or ocean.

We need to know three things to be able to draw servicesheds:

Where ecological processes produce a service, creating supply. There may be demand for a service, like protection from coastal storm surge, but if there are no natural habitats in the coastal zone to buffer waves, then there is no supply of that service.
Where people have physical access to that supply. A watershed may be providing clean water, but if no people have wells, pipes, paths to the river or other means of physically taking water, then that service of clean water is not being provided to people.
Where people have institutional access to that supply. This basically reflects access rights. In some parts of the world, these come in the form of legal rights like use zones, water use rights, fishing permits and so on. In other parts of the world, informal rules determine access, like in Cambodia, Kenya and many other countries where communities restrict access to spirit forests, or seasonal no-take zones for fisheries.

The serviceshed for carbon sequestration is the entire planet because the atmosphere is well mixed. Carbon sequestration anywhere by any plants benefits all people. For water-related services (e.g., drinking water supply, hydropower supply, water purification, flood mitigation, erosion control), the serviceshed is the land area upstream of the place where people legally access water. In the water services map, we see the lower part of the map is not in a serviceshed because there is no city downstream. The middle part of the map is in one serviceshed because it has one city downstream (black dot), and the upper part is in two servicesheds, with two cities downstream.

Crop pollination benefits are provided very locally. The distance that wild crop pollinators can fly defines the serviceshed around a field with pollinator-depending crops. Some servicesheds can be more complex to define, like those shown in the servicehsed map for clean water for fish. In this map, we see five lakes that have recreational fish populations near a city. Each of the lakes' watersheds can act as a filter that keeps the water clean and supports healthy fish populations, and so provides the 'supply'. People are willing to drive as far as the white boundary to go fishing (demand), but lake 4 is not in the serviceshed because it does not have road access (physical access). Lake 5 is too far away and has no road (again, no physical access), and lake 3 is protected and closed to fishing (institutional or legal access). This leaves lakes 1 and 2 within the demand area for the city, with both physical and institutional access. So the serviceshed for this one ecosystem service is the watershed areas of those two lakes.

We have used servicesheds to help understand who will lose drinking water quality and carbon sequestration benefits from the construction of a road in the Peruvian Amazon. In that same case, we used servicesheds to see who will gain the same benefits from mitigation activities like protection and restoration of native habitats. This approach helps us design mitigation that returns the same benefits to the same people, maintaining social equity.

We have also used servicesheds to help us account for water quality and climate regulation in national accounts, see: Inclusive Wealth Report 2012. Measuring progress toward sustainability.

Please contact Heather Tallis htallis@stanford.edu for more information.