- ‘Ecosystem services’ are services provided by nature, vital for human existence.
- An ecosystem services assessment (ESA) can assess how effectively these services will be provided under different scenarios. In some cases it can also be used to assess the financial value of these services.
- The ESA shows how forests and other important ecosystems may be affected by the complex interactions of different interventions and supply chains.
What are ecosystem services?
‘Ecosystem services’ are the services provided by the natural world. Forests provide many of these services, including clean air, pollination, filtered water, greenhouse gas sequestration and so on. Human economies depend on these services, especially in areas such as farming.
Why carry out an ESA?
The ESA is important because different interventions can potentially interact in complex ways, with unforeseen effects on the forest and other ecosystems. The assessment aims to project the initiative's overall effect on the landscape as a whole. This is in contrast to environmental impact assessments, which look at individual supply chains.
Ultimately, the ESA can be used to calculate the 'biophysical value' of these services in the landscape - for example water regulation or carbon storage - and how these values may change. In some cases ESA results can also be used to calculate the financial value of these services.
The assessment uses Geographic Information Systems (GIS) to analyse changes in land use under different scenarios: business as usual (BAU) and sustainable ecological management (SEM). It assesses how changes in cultivated areas may impact forest and other important ecosystems.
To carry out an ESA, researchers will need to make certain assumptions about the future. These are the same assumptions as used for the cash flow models.
The ESA give the user the opportunity to assess different ecosystem services considered a priority, and depending on available information. For example, some donors or investors may be more interested in carbon emissions or effects on the hydrological cycle. In the UFF projects, the ESA analysis produced two key measures, avoided deforestation and overall carbon emissions/carbon sequestration.
Data needs for ecosystem services assessment can be found in the following file:
A note on using models
While useful, initiatives should not rely solely on computer based projections. Such models are based on assumptions of people’s behaviour, which are extremely hard to predict.
For this reason, researchers should use these models alongside a range of other information sources such as interviews with experts and producer organisations. Moreover, models should be validated against historical data to make sure that they can replicate what has happened before, thus proving that they are effective.
Lastly, models’ projections of environmental benefits does not mean that these benefits are guaranteed, so they will still need proper Codes of Conduct and a monitoring programme to ensure the best possible results.