Destisol: A decision-support tool to assess the ecosystem services provided by urban soils for better urban planning

Abstract

Urban soils exhibit a wide diversity of properties that have no equivalent in other environments but are overwhelmingly perceived as degraded by decision makers. As a result, their potential is not considered in urban planning even though they can deliver a range of ecosystem services. This paper describes a decision support tool for assessing soil ecosystem services to support urban land use planning. An overview of existing methods for assessing ecosystem services provided by urban soils has been detailed. Destisol, a model developed specifically for the urban context, is presented in detail. Destisol was then applied to 37 urban soils under various situations and pedoclimates. The main innovations of Destisol lie in the consideration of soil properties throughout the whole pedon and in the evaluation of the compatibility of the soil with different land covers. It is based on the acquisition of soil indicators, which are transformed into scores of soil functions, then into compatible land covers and finally into scores of ecosystem services. The architecture of the model is based on 20 physico-chemical-biological soil indicators used to score 15 soil functions, based on a detailed set of decision rules. The soil functions scores allow the calculation of a percentage of compatibility for 13 land covers. Finally, the resulting scores are used to evaluate 18 ecosystem services, as a function of land cover. The tests show a wide distribution of scores depending on the soil studied, but also depending on the soil function, land cover or ecosystem service considered. Technosols show the largest dispersion of soil function scores, and no correlation was found between the anthropization gradient and the mean soil function score. The main results of Destisol are an assessment of the soil suitability, that is the compatibility between a soil and a land cover, and an explicit assessment of the ecosystem services provided depending on the land covers.