A methodological framework to assess the multiplicity of ecosystem services of soils at regional scale

Methodologies used for identifying, assessing and mapping ecosystem services are diverse and frequently inconsistent and notwithstanding the examples from available literature, evident methodological gaps are still present. This paper presents an indicator based approach to assessing and mapping the multiplicity of ecosystem services provided by soils, based on available soil data for a reference depth of 100 cm. Of operational value is the fact that, within this framework, several services can be treated and mapped simultaneously, providing an efficient tool to model the heterogeneity of different soil functions, both at local and regional scale. The methodology consists of: (i) definition of soil based eco-system services, based on available soil data and on societal demands; (ii) definition of appropriate indicators and coding; and (iii) assessment and eventually mapping of soil based multiple ecosystem services. In this work we used spatial data to characterize and model the spatial heterogeneity of provisioning and regulating soil services in the case study area of alluvial plain of Emilia Romagna (Northern Italy). In order to explicitly take into account the spatial variability and the related uncertainty, and in order to exploit at best the available information, we: (i) realised a continuous coverage of basic soil properties via geostatistical simulation conditional on available 1:50,000 soil map and land use map, and (ii) derived the relevant soil properties via locally calibrated PTFs and using other available information, such as the land capability map. Results provide new insights about the composition and interrelation of multiple soil functions and services in the region and highlight the difference between soils in term of joint services provision.