Biodiversity conservation requires balancing trade-offs between biodiversity protection and economic activities. This applies both to protected areas, where the supply of various ecosystem services (e.g. carbon sequestration, water regulation) is seen as an important co-benefit, and not-protected areas, which also contain important elements of global biodiversity. Balancing trade-offs in biodiversity conservation requires information on the monetary values provided by ecosystem services under different land cover and with different management, on the linkage between ecosystem services and economic activity and on trends in ecosystems and the services they supply. Ecosystem accounting is grounded in the system of national accounts (SNA) and provides a consistent and comprehensive framework for analysing ecosystem services at the national or sub-national scale. It follows a spatial approach where ecosystem condition, ecosystem services flows and ecosystem assets are mapped, in order to provide accurate information on spatially heterogeneous ecosystems.
The work on ecosystem services modelling and valuation has mushroomed in recent decades. A challenge in comparing ecosystem services assessment and aggregating data of different assessments is that several different approaches are used, in terms of defining, measuring and valuing ecosystem services. The advantage of ecosystem accounting is that a consistent framework is available that is grounded in the specific methodology of the System of National Accounts. This also facilitates comparison of services and their values with indicators provided by the national accounts such as GDP.
The ecosystem accounting approach comprises a set of accounts, in the form of maps and tables, in particular: the ecosystem condition account, the ecosystem production account (recording flows of ecosystem services), the ecosystem asset account (recording stocks of ecosystem capital and changes therein), the supply-use account (connecting the suppliers of ecosystem services such as land owners and the users of ecosystem services) and the biodiversity account (providing specific information on biodiversity based on ecosystem and country relevant indicators). The methodology has been tested in several countries, but is still under development, for instance with regards to the indicators to use in the biodiversity account.
Testing the ecosystem accounting approach in currently around 5 to 10 countries demonstrates that comprehensive Ecosystem accounts can be prepared, even in environments with relatively poor data availability. These accounts are invariable highly useful in informing policy makers on key environmental and resource management issues. However, their compilation requires a significant investment in terms of time, resources, and capacity building. Data needs to be collected from a broad range of sources and support from different data owners is required. Given the efforts required in building capacity and the fact that the Ecosystem accounts are particularly useful to monitor trends in ecosystems and the services they supply, a long-term perspective is needed.