Are preferences for soil-based ecosystem services driven by spatial phenomena?

Agricultural soils provide multiple ecosystem services that affect human well-being. Soils’ potential to provide these ecosystem services varies spatially. Socio-demographic and other drivers of environmental preferences are also spatially variable. Therefore, preferences for soil-based ecosystem services are likely to be spatially heterogeneous, which may result in different policy priorities across locations. Understanding this spatial heterogeneity of preferences is therefore essential to guide public policy to protect healthy soils. We present a study that combines explorative and hypothesis-driven approaches to understand the spatial heterogeneity of preferences for four soil-based ecosystem services: climate regulation, clean water provision, drought protection and flood protection. Based on the results of a discrete choice experiment conducted on a representative sample of the German public, we first use global and local spatial autocorrelation measures to test whether there are any obvious patterns in the spatial distribution of preferences. Second, we use spatial lag models to test a number of hypotheses to explain the observed preference heterogeneity. We particularly focus on the spatial variability of relevant phenomena such as floods, droughts or nitrate pollution of groundwater, and their effects on the studied preferences. Lastly, we compare the results from both approaches in order to see whether the identified patterns are consistent with each other. We find weak patterns of spatial heterogeneity, but our hypotheses are all rejected. This suggests that salience of relevant phenomena and individual affectedness do not have an effect on preferences for soil-based ecosystem services.