Background: Urban development has been defined by expansion of urban structures into surrounding rural areas, cropland and forests. Urban soils are created by the process of urbanization, therefore they become an immanent part of the urbanized areas. Urban activities could create different types of new man-made soils, but all soils situated within cities or urbanized areas should be included to category of urban soils. Due to a multi-functional role of the soil in urban areas the sound management of this resource is of a key importance in urban land management. Typology of urban soils is important to perceive these soils through the wide perspective including diversity of soil functions. It is also important to define the suitability of soils for different urban land uses. Soil characteristics and quality should be take into consideration by spatial (urban) planning. From the perspective of ecosystem services and SSW system, urban soils are important part of green infrastructure. Especially soil of a high quality should be protected to maintain the habitat and support ecosystem services potential. Also agricultural role of soil in urban areas should not be neglected, especially in the context of urban farming and gardening, as well as from the perspective of the global food production market.
Goal: Better understanding the role of urban soils and their importance on improving quality of urban space and consequently on health and living quality.
Rationale from the themes: Demand: Demand for soil in urban areas is connected with the need for food production (agricultural function and urban gardens areas), recreation areas but also other unsealed areas and green areas. They are needed for ecosystem services, biodiversity and climate change adaptation support. These functions compete with other like housing, infrastructure, transport and industry. Soils are subjected to major changes, especially those resulting from investment and construction activities. Soils have also to cope with high load of waste materials like solid waste, sewage and chemical pollutants.
Natural Capital: Soil as an important part of our natural capital are providing a lot of ecosystem services to society. Soil fertility refers to the ability of a soil to sustain plant growth. That’s why the restoration or re-cultivation of unused or polluted areas is essential for protection of urban soils. Soil is functioning as a water reservoir (40% of soil is porosity). In order to provide a cooling effect better soils have better “water” efficiency. This role of soil in urban areas is extremely important. That’s why urban soils management need to consider impacts on groundwater and surface water.
Land Management: There is a need of joining the soils management and land use management in urban areas. The urban soil are not enough protected in many countries, It is mainly connected with changing the agricultural function into different one (e.g. housing, industry and urban infrastructure) therefore in a consequence we have a significant fragmentation of the landscape in urban areas. Urban sprawl plays an important role in this process, by increasing soil sealing. Also functions of industrial, urban soils are important from the perspective of integrated land management. Effective, integrated urban soils management needs to define rights and duties of private owners. For spatial planning procedures is important to introduce new solution concerning economic scenarios for urban soils management. These scenarios should propose solutions like temporary use of urban abandoned soils as an alternative to remediation when this is not economically feasible. Scenarios could also propose compensations instruments related to protection of green fields and uses of brown fields, as well as management of contaminated soils.
Net Impact: The role of soil in urban areas seems to be more and more important in the context of a present threats coming from climate change and demographic impacts. In a global scale this threat is visible in all urban areas. Therefore there is a need of scientific argumentation to what extent ecosystem services in urban areas can contribute to decrease negative impact and could support biodiversity preservation.
So what? In order to steer better use of urban soils in a sustainable way, a proper management of soil resources is needed. The soil management systems that efficiently protect the best soils should be introduced in cities. There is also need of reuse and improving of urban soil quality by innovative remediation technologies. A multidisciplinary approach is necessary for better understanding of the soil role in urban environment in order to ensure its optimum use and provide the functions needed, like water filtering and storage, space for fauna and flora, provision of recreation areas etc. Human health is also important in the context of urban soils management, and should be take into account in urban planning and land management.
Links to other fields: Next to urban soils, also water and sediments in urban areas are important in the context of ecosystem service research.