7.3 Ecosystem services and land use / cover
- To introduce the concept of ecosystem services
- To describe the GIS techniques that can be used to measure ecosystem services through specific examples
Concepts in ecosystem services
Ecosystem services are defined as the benefits to people that are to be gained from the environment (ref). Closely related to this is the idea of natural capital, defined as ‘natural assets in their role of providing natural resource inputs and environmental services’. (OECD, 2012). Ecosystems can be considered as one form of natural capital, alongside land and stocks of natural resources (oil, natural gas, timber, fish, etc). The benefits people gain from the environment are often categorised into different types as follows:
Table 1. Examples of different types of ecosystem service
|Type of service||Example|
|Habitat services||primary production; nutrient cycling|
|Provisioning services||water supply; fuelwood|
|Regulating services||flood mitigation; water purification; carbon sequestration|
|Cultural services||recreational visits to the countryside|
Ecosystem services has its theoretical groundings in economics, and so these various services can be considered a form of public good. Unlike goods that might be purchased through a shop, use by one individual does not prevent others from using public goods (such as green spaces for recreation) and public goods are available to all. As such, an economic (monetary) value can be attached to each of them and in this way, a value placed on the various services that the environment provides to both the local and global population.From an environmental management perspective, being able to quantify the benefits that the environment provides to humankind can help build the case for the financial resources needed for environmental protection and stewardship.
GIS and ecosystem services
From a GIS perspective, often land use / cover is a key map layer in estimating the value of ecosystem services. One such example is the idea of carbon sequestration, in other words the capture and long-term storage of atmospheric carbon dioxide by plants, an example of a regulating ecosystem service. Carbon sequestration is however a complex process, involving not only land use /cover information, but also soil type and meteorological process. Estimating the carbon fluxes associated with particular land use / covers requires considerable scientific modelling (Vleeshouwers and Verhagen, 2002). In view of this, a benefit transfer approach is sometimes adopted by economists, in which the economic value of ecosystem services attached to land use / cover categories at a given site is derived from similar land use / covers elsewhere. Troy and Wilson (2006) suggest 7 steps to valuing ecosystem services through such approaches:
- Define study area
- Develop land use/cover typology
- Search literature for value estimates to associate with each land use / cover type
- Map out values by land use / cover type
- Calculate the total value of ecosystem services across the study area
- Generate summaries of total value by sub-regions, e.g. watersheds or other environmental management units
- Explore future development scenarios
In recent years, software tools have been developed that enable the value of ecosystem services to be estimated spatially. Prominent amongst these is the Integrated Valuation of Environmental Services and Tradeoffs (InVEST) tool developed by the Natural Capital Project (see references below).
Case study – the REDD programme
Reducing Emissions from Deforestation and Forest Degradation (REDD) is an international effort to value the carbon stored in forests around the world. The programme involves the United Nations through a UN-REDD programme. More recently, the programme has been extended beyond simply forest loss through deforestation to proactive measures to conserve and manage existing forests through a new REDD+ phase. Valuation of the carbon sequestered in forests enables specific financial incentives to be put in place to enable forests to be protected and managed sustainably. To support the consistent estimation of sequestered carbon and its value, the UN-REDD have developed a set of tools for ArcGIS (see links below).
Take a closer look at one paper from the suggested readings below (or if you prefer, search for and choose an article about an ecosystem service of interest to you that is not on the list). What do you see as the strengths and limitations of the approach taken in your chosen article? Post your thoughts to the discussion board.
References (Essential reading for this learning object indicated by *)
This article describes how GIS can be used to value ecosystem services through benefit transfer:
* Troy, A. and Wilson, M. A. (2006) Mapping ecosystemservices: Practical challenges and opportunities in linking GIS and value transfer. Ecological economics 60 (2) 435-449.
One of the main software tools for mapping ecosystem services is produced by the Natural Capital Project and is known as InVEST. InVEST is a plug-in for ArcGIS and is freely downloadable, together with associated manuals and training materials via this link:
The UN-REDD have also developed a plug-in tool for :
* Velarde, S. J., Malhi, Y., Moran, D., Wright, J. A. and Hussain, S. (2005) Valuing the impacts of climate change on protected areas in Africa. Ecological Economics 53 (1), 21-33.
* Vleeshouwers, L. M. and Verhagen, A. (2002) Carbon emission and sequestration by agricultural land use: a model study for Europe. Global Change Biology 8, 519-530.
* Bateman, I., Lovett, A., and Brained, J. (1999) Developing a Methodology for Benefit Transfers Using Geographical Information Systems: Modelling Demand for Woodland Recreation. Regional Studies 33 (3), 191-205.