Modelling of Soil Multifunctionality Across Europe

Abstract

Soils sustain a number of functions playing a key role in ecosystem functioning and providing a multitude of services to human society. While it is acknowledged that all soils are multifunctional, there is, to date, limited knowledge on how the supply of soil functions and their combination differ spatially with land use type, soil characteristics, climate and land use intensity at large geographical scales. We address this gap by quantifying five functions of major importance to European soils: (1) primary productivity, (2) water regulation, (3) climate regulation, (4) nutrient cycling and (5) provision of habitat for biodiversity. We built a multi-attribute semi-quantitative model with a hierarchical structure. The model is structured for the large-scale evaluation of soil functions and takes as input a set of indicators related to dynamic and stable soil properties, as well as climate, topography and management practices, and returns qualitative aggregated attributes representing the soil functions supply. Thresholds for the soil functions supply are obtained by statistical analysis coupled with expert knowledge and vary across European environmental zones. The model is tested utilizing a large pan-European dataset focused on cropland and grassland systems. Statistical distributions of soil functions supply are obtained alongside alpha- and beta-multifunctionality representing the diversity of soil functions represented at a sampling location and the unique contribution of the sampled site to the regional (i.e. NUTS3 level) soil functions supply, respectively. We found that the supply of soil functions varied greatly across landscapes in Europe and between environmental zones. Spatial patterns of the alpha- and beta-multifunctionality revealed hotspots of multifunctionality (alpha multifunctionality) but also sites providing a set of soil function delivery unique within the region (beta multifunctionality). Few sites are both unique and highly diverse. Our study set a baseline estimate of soil functions in Europe as a prerequisite to consider soil functions in environmental planning.