Analysis of Volume and Properties of Imported Soils for Prediction of Carbon Stocks in Soil Constructions in the Moscow Metropolis

Assessing Soil-like Materials for Ecosystem Services Provided by Constructed Technosols

“…Taiga and mixed forests on the Retisols dominating the natural areas of the region, in Moscow city, are to a great extent substituted by ornamental plants and green lawns on man-changed or man-made soils with a considerable portion of constructed Technosols [32,33]. More than 1 million m 3 of soil-like materials (e.g., organic and mineral components and commercially manufactured mixtures) are annually imported into the city for the needs of civil engineering and green infrastructures' development [5,8,34]. A major part of the commercially manufactured mixtures available on the market composes from the similar components: valley peat, topsoil from meadow or arable lands, urban topsoil, and subsoil excavated before building construction, excavated river valley topsoil, compost, sand, dredged sediments, and sludge from water treatment stations.…”

“…A high rank of the sediments, which balanced most of the analyzed services, is one of the principal and unexpected research outcomes. So far, dredged sediments are frequently used in agriculture as amendments [56][57][58], but in urban greening and landscaping, preference is traditionally given to C-rich 'dark' materials, which are supposed to be more fertile [5]. In fact, dredged sediments combined with biosolids can considerably improve soil fertility and support plant growth as it was shown for Chicago [9].…”

“…In comparison to sediments, a considerably lower capacity to provide climate regulation and C-sequestration services was shown for the valley peat and high-peat mixtures, which so far dominate the greening markets of Moscow [5,34] and many other cities in Europe [62]. Although the nutrient content in peat materials is high, their vast implementation for Technosols' construction can result in a dramatic increase in CO 2 release to the atmosphere due to intensive mineralization of easily mineralizable organic matter [63,64], which can be even more facilitated by urban heat island effect [65].…”

“…From a variety of urban soils, soil constructions (constructed Technosols) are likely the most attractive and challenging for environmental assessment and modeling. Annually, thousands of tons of organic and mineral materials are imported into a big city and utilized for Technosols' construction [5][6][7]. The technologies and materials used for Technosols' construction are selected considering the management purposes, e.g., for reclamation, landscaping, establishment, and maintenance of urban green infrastructures [8][9][10][11].…”

“…In the United States, particularly in Chicago, biosolids and dredged sediments are implemented for renovation and greening works [9,14]. In Moscow, Russia, there are at least 50 companies, supplying about a hundred of different materials for greening, mainly comprised of peat, sand, compost, and excavated topsoil in different proportions [5,8].…”