This sub-section documents the methods and concepts that are useful to assess the conditions and trends of ecosystems and ecosystem services. Often, but not always, ecosystem services results from the functioning of ecosystems as flows of renewable resources. Overexploitation of ecosystem services may jeopardize ecosystems integrity thereby affecting those services.
The assessment of ecosystems aims at examining the sustainable use of the natural capital. This requires evaluating both stocks and flow of ecosystem services, as well as ecosystem integrity, through indicators and proxies. Environmental accounting techniques are being used for that purpose.
Different sets of indicators are sometimes aggregated into indices (e.g. the ecological footprint) for communication purposes.