Soil Ecosystem Services

Abstract

Sustaining soil productivity in response to climate change is critical for two reasons: feeding the world under straitened circumstances, plus adapting to and mitigating climate change itself. The supporting, provisioning and regulating ecosystem services provided by soil are critical for food provision and for meeting the challenges of climate change. We outline how an ecosystem services approach that recognises and values the soil‟s natural capital stocks of carbon, air, water, and water, might offer a means to ensure maximised use of natural capital and minimised use of added capital resources. We present three examples of securing sustainable returns on investment into the soil‟s natural capital: we link soil processes controlled by carbon to soil ecosystem services; we value supporting and regulating soil services in the provision of terroir value for wine; and we use a valuation of the soil‟s natural capital to allocate a nutrient-loss right for policy to limit non-point source pollution by nutrients from farms. Firstly, we found for two similar soils that had undergone 12 years of apple growing using different carbon-management practices, phenoforms had developed with different levels of soil carbon. Thus the natural capital value of the soil with the higher carbon content we found to be greater as a result of its enhanced supporting and regulating ecosystem services. Conversely for vineyard soil we found that natural capital value declined with increasing soil carbon throughout the profile, for the terroir lessened as a result of excessive vegetative vigour resulting from greater nutrient provision and water storage. However, if a mulch just raised the carbon content of only the surface soil, then the natural capital value of the soil would be enhanced through better supporting, regulating and provisioning services. Finally we outline how soil scientists can become involved with policy analysts to develop a nutrient management policy that is based on the concept of natural capital. This policy does not focus on capping inputs, but rather it seeks to engage with land-users to maximise their return on investment into their natural capital assets and to encourage their sustainable management of the landscape‟s biophysical resources without compromising the ecosystem services of receiving environments.