A soil change-based methodology for the quantification and valuation of ecosystem services from agro-ecosystems: A case study of pastoral agriculture in New Zealand

This paper tests the steps required to transform a theoretical natural capital/ecosystem service framework for soils into an operational model. Each of the services provided by a volcanic soil under a pastoral dairy use are quantified and valued. The six guiding principles underpinning the method developed include differentiating soil services from supporting processes; identifying key soil properties and processes behind each service; distinguishing natural capital from added/built capital; identifying how external drivers affect natural capital stocks; analysing the impact of degradation processes on soil properties and basing the economic valuation on measured proxies. Proxies to quantify ecosystem services focus on the part played by soil in generating each service. This new approach highlights the importance of soil change in quantifying services, and goes beyond simply determining the status of soil natural capital. The total value of the ecosystem services provided by a volcanic soil under dairy in the Waikato region in New Zealand was estimated at $16,390/ha/year on average over 35 consecutive years. The services with the highest value were the filtering of nutrients and contaminants (58–63% of total value), followed by the provision of food and then flood mitigation. Regulating services had an economic value 2.5 times more important than provisioning services.