Toxicological state and chemical properties of soils in urbanized ecosystems of Murmansk

Abstract

Nowadays, active urbanization directly affects to the transformation of natural ecosystems in all natural zones of Russian Federation. First of all, soils of the cities are exposed to undergoing to intensive transformation. With this transformation, natural soils change to urban and “urbo-natural soils”. Arctic ecosystems are most susceptible to anthropogenic influence because they have a low regeneration and restoration ability. Urban soils demonstrate numerous and various processes of transformation and migration of substances, which are the most important links in the biogeochemical cycles, linking the various structural components of ecosystems and the biosphere as a whole. In this context the processes of soils transformation under the influence of the urbanization has been considered. Soils of residential, recreational (park), industrial and non-developed urban zones were studied on example of Murmansk city as one on the northernmost city in European part of Russia. Microbiological activities, toxicological state (heavy metals, Zc), and content of carbon in soils were revealed.

Urbanization Affects Soil Microbiome Profile Distribution in the Russian Arctic Region

“…In both investigated urban sites, pH H2O was significantly higher than in the natural soil, with a more remarkable shift for the MUR-U2 site, which was recently developed and exposed to more intensive management. Topsoil SOC content in urban soils was comparable to the previous studies for Murmansk [ 11 , 31 ], Salekhard [ 56 ], and some other polar cities [ 46 , 57 ] and higher than reported for the natural Podzols in the region [ 29 , 36 ]. In the investigated MUR-NR site, however, SOC content in the topsoil O horizon was much higher than in the urban sites due to slow decomposition of the plant residuals in Subarctic conditions resulting in peat formation.…”

“…This is likely explained by the abundance and availability of organic matter [ 66 ] and relatively low pollution by heavy metals compared to Monchegorsk or Apatity settlements [ 67 ]. The previous studies also did not report considerable pollution in the residential areas of Murmansk, whereas a higher content of heavy metals was shown for the industrial areas and traffics zones in comparison to the natural sites [ 11 , 30 ]. As a big city, Murmansk is exposed to a stronger urban heat-island effect than any other settlement in the region, which in combination with the warming effect of the Gulf Stream creates favorable climatic conditions for soil microbiota [ 68 ].…”

“…The content of heavy metals in urban soils was higher than in the natural Podzol ( p = 0.01088). Topsoil contents of Pb, Zn, and Ni in urban soil were also above the health thresholds (maximum permissible concentration) [ 47 , 48 ]; however, the values were much lower than reported for the industrial areas in the region [ 8 , 11 ]. Phosphorus concentrations in urban topsoils were 2–3 times higher than in the natural areas, which was especially evident for the MUR-U1 profile at the central part of the city.…”

“…The environmental consequences of urbanization in the Arctic are overlooked so far; however, changes in Arctic vegetation and soils driven by urbanization can be irreversible and dramatic [ 7 , 8 ]. Industrial and mining activities result in severe environmental pollution, which affects the vegetation state and diversity [ 9 ] and soil quality [ 10 , 11 ]. At the same time, the urbanization effect on soils is not limited to pollution.…”