ИСТИНА

Urban areas are likely to increase worldwide due to a number of factors such as economic growth, population increase, rising living standards, availability of cheap agricultural land, inner city problems, increased wealth per household, and enhanced personal mobility. Since the mid‑1950s, the total surface area of European cities has expanded on average by 78 % while the population has grown by just 33 %. An analysis at the 1‑km2 grid level shows that the most pronounced sprawl in peri-urban areas is in wide circles around city centers, along large transport corridors and along many coastlines. About 80 % of newly developed urban land consists of settlement areas. The majority of newly developed urban land was previously used for agriculture. The relative contribution of agricultural land to uptake by peri-urban land is about 73 % in Europe (46.2 % arable land and 26.7 % pastures), 84 % in Germany (63 % arable land and 21 % pastures), and 91 % in Hungary (69 % arable land and 22 % pastures). Furthermore, Europe's agricultural land continues to decrease at an average rate of 0.1 Mio ha per year. The same trend can be observed in developing countries at a rate of about 0.5 Mio ha per year. Most affected by urban sprawl during the 20th century was Russia, where about 64 Mio ha of former agricultural land around the cities was converted into urban land. Thus, urban expansion on arable land is a typical pattern of land use change in human history worldwide, with an increasing impact at present. Conversion of agricultural land to peri-urban land is an important challenge that has received little attention thus far. Trends in carbon balance and potential of soil carbon sequestration, soil properties and soil functions after such land use change needs to be assessed. It is expected that newly initiated pedological processes and inputs of new materials due to human activities, that occur in peri-urban areas simultaneously, will result in changing soil morphology, carbon sink functions, and biological activities. Additionally, the formation of new human-natural bodies, from which classification problems will likely arise, require resolution. First investigations are in progress in Hungary (Debrecen area), Germany (Oldenburg area), and Russia (Belgorod area) and will be presented at the congress.