Guidelines for assessing soil ecosystem services in urban environment and their management - LIFE15 ENV/IT/000225 GUIDELINES ACTION B1.3

Urban soils are deeply influenced by human activities. They consist of materials different from those of nearby agricultural or natural areas, due to mechanical disturbance, supply or removal of material, contamination with exogenous materials (plastics, asphalt, pollutants, etc.). They are the result of urbanization activities that involve total or partial sealing of the surfaces (Morel et al. 2005). The development of urban soils is controlled by the same factors as natural soils, with a clear and important prevalence of the anthropic factor. The survey of urban soils therefore follows the same criteria of surveying natural or agricultural soils, taking into account that the anthropic disturbance in addition to being prevalent acts in a very short time. This causes a strong heterogeneity in the spatial distribution of the soils and of their characteristics that is problematic to solve in a detailed soil map. Human disturbed soils are classified (FAO World Reference Base For Soil Resources, IUSS - Working Group WRB, 2014) as: o Anthrosols: soil that has been formed or heavily modified due to long-term human activity, such as from irrigation, addition of organic waste or wet-field cultivation used to create paddy fields o Technosols: are dominated by their technical origin. They contain either a significant (20% or more) amount of artefacts or some sort of geotechnical liner, or are sealed by technic hard rock (hard material created by humans, having properties unlike natural rock). Urban soils perform the same functions as a natural soil contributing to the provision of Ecosystem Services. However, the degree of disturbance to which they are subjected, the level of sealing and the type of coverage have an influence that needs to be described in detail and taken into account. Given the great variability of the urban environment and the differences between different urban environments, there are still no standardized references for the survey and mapping of urban soils. There are some experiences, such as the map of the city of Berlin (https://www.stadtentwicklung.berlin.de/umwelt/umweltatlas/dinh_01.htm) and of New York City (http://www.soilandwater.nyc/urban-soils.html). Within the SOS4LIFE project, a methodology has been developed for defining urban soil mapping units in the study case of the town of Carpi (MO), based on the type of "natural" soils below the urban fabric, the urban typologies and the land cover of unsealed soils. Considering that most of the SEs in urban areas are provided by green areas, the assessment of soils and related functionality has been concentrated in gardens and parks, sports fields and on peri-urban agricultural areas. The gardens in private allotments were not considered, having verified the high degree of impermeabilization of the same (driveways, parking lots, access ramps to garages, etc.). However, even these soils, although strongly altered, maintain some functionalities. The SEs considered are therefore generally underestimated for the entire city.