Defining and Mapping soil based ecosystem services at different scales: a flexible methodological approach at multiple governance levels

We present an indicator based approach developed within the LIFE+ project SOS4LIFE LIFE15 ENV/IT/225 to make spatial prediction and representation of soil ecosystem services. Within the presented framework, based on the availability of soil data for a reference depth of 100 cm, several indicators are treated and mapped simultaneously, providing an efficient tool to model the heterogeneity of different soil functions, both at local and regional scale. The implemented approach consists of: (i) definition of soil functions behind the delivery of ecosystem services, based on available and derived soil data and on societal demands; (ii) definition of appropriate function indicators and coding; and (iii) assessment and mapping of soil-based multiple ecosystem services at different scales, i.e. from regional to municipal level in the case study area of the alluvial plain in Emilia Romagna (Northern Italy). At the regional scale, in order to explicitly take into account the spatial variability of soil properties and the related uncertainty, we adopted a DSM approach encompassing the following steps: (i) realization of a continuous coverage of basic soil properties via geostatistical simulations conditional on available 1:50,000 soil map and land use map, and (ii) estimation of the necessary soil properties via locally calibrated pedotransfer functions and using other available information, such as land capability map. At the local scale, i.e. municipality level, the same indicators for the same soil-based ecosystem services, were assessed using available data from benchmark soil profiles. The approach incorporates the local understanding of soils geography and land use at different scales, and via PTFs, it links soil processes and properties at the base of the supply of each soil ecosystem service to a standardised estimation of each service. The identification of multiple soil service areas and the understanding of their spatial patterns and connectivity can provide a further strong basis to support land planning and management. The presented approach can then be viewed as a recalibration of classical land evaluation schemes in which an ecosystem approach is tailored to take into account specific soil properties which underpin specific services through the use of specific indicators calibrated on local soil variability. The approach allows to establish clear links between decisions and soil ecosystem services as it makes clear where and to which extent different services are potentially provided by different soils and in which constellation, allowing to assess the risk of service loss or the chance of services maintenance or enhancement under different policy and management options.