A review and application of the evidence for nitrogen impacts on ecosystem services

Levels of reactive nitrogen (N) in the atmosphere have declined by around 25% in Europe since 1990. Ecosystem services provide a framework for valuing N impacts on the environment, and this study provides a synthesis of evidence for atmospheric N deposition effects on ecosystem services. We estimate the marginal economic value of the decline in N deposition on six ecosystem services in the UK. This decline resulted in a net benefit (Equivalent Annual Value) of £65 m (£5 m to £123 m, 95% CI). There was a cost (loss of value) for provisioning services: timber and livestock production of −£6.2 m (−£3.5 m to −£9.2 m, 95% CI). There was a cost for CO2 sequestration and a benefit for N2O emissions which combined amounted to a cost for greenhouse gas regulation of −£15.7 m (−£4.5 m to −£30.6 m). However, there were benefits for the cultural services of recreational fishing and appreciation of biodiversity, which amounted to £87.7 m (£13.1 m to £163.0 m), outweighing costs to provisioning and regulating services. Knowledge gaps in both the under-pinning science and in the value-transfer evidence prevent economic valuation of many services, particularly for cultural services, providing only a partial picture of N impacts which may underestimate the benefits of reducing N deposition.