Measuring and Modeling the Ecosystem Services Delivered By Soil Hydrological Processes.

Nature comprises an assemblage of natural capital stocks, and they, in sum, form our ecological infrastructures. Soils and plants are key components of our diverse ecological infrastructures, and they are prime natural-capital stocks that provide valuable ecosystem services, primarily through the soil and plant hydrological processes that operate in the rootzone. Of the four ecosystem service classes, here we focus on the two of how soil and plant hydrological processes deliver the provisioning services of food, fibre and fuel, along with the regulating services of buffering and filtering water, nutrients and pesticides. We consider how soil and plant hydrological processes in the saline desert sands of the hyperarid UAE serve to maintain the provisioning service of date production through irrigation.  Next we assess the impact of soil water repellency on hydrological processes which can deleteriously affect the provisioning service of pasture production in New Zealand hill country. Then we show how canopy management of avocado trees in the Kenyan highlands can alter soil hydrological processes to regulate the service of soil-water delivery to the trees and can be manipulated to enhance the resilience to the drought which occurs between the two rainy seasons. As well, we discuss how soil-water repellency affects the buffering and filtering regulation services of soil in relation to the transport and fate of the pesticide 2,4-D.  We show how better fertilizer management practices can be developed to enhance the regulating service of the buffering and filtering of the nutrients used in potato production so as to protect the underlying groundwaters from leachate loadings.  Finally we show how reference to natural capital and the ecosystem services delivered by soil and plant hydrological processes can be incorporated into policy and laws to maintain provisioning services whilst sustaining regulation services, and how these can be successful in judicial hearings.