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The aim of the present study was to establish the effect of management type and of environmental variables on the structure, abundance and species richness of soil mites (Acari: Mesostigmata) in twelve urban green areas in Bucharest-Romania. Three categories of ecosystem based upon management type were investigated: protected area, managed (metropolitan, municipal and district parks) and unmanaged urban areas. The environmental variables which were analysed were: soil and air temperature, soil moisture and atmospheric humidity, soil pH and soil penetration resistance. In June 2017, 480 soil samples were taken, using MacFadyen soil core. The same number of measures was made for quantification of environmental variables. Considering these, we observed that soil temperature, air temperature, air humidity and soil penetration resistance differed significantly between all three types of managed urban green area. All investigated environmental variables, especially soil pH, were significantly related to community assemblage. Analysing the entire Mesostigmata community, 68 species were identified, with 790 individuals and 49 immatures. In order to highlight the response of the soil mite communities to the urban conditions, Shannon, dominance, equitability and soil maturity indices were quantified. With one exception (numerical abundance), these indices recorded higher values in unmanaged green areas compared to managed ecosystems. The same trend was observed between different types of managed green areas, with metropolitan parks having a richer acarological fauna than the municipal or district parks.

An anthropic ecosystem from Romania was investigated from acarological, vegetation and chemical point of view. The community structures of two groups of mites were studied (Acari: Mesostigmata, Oribatida) from a tailing pond, using transect method, in correlation with concentrations of heavy metals (As, Cu, Pb, Ni, Mn and Zn), with abiotic factors (altitude, aspect, soil temperature, soil humidity, soil pH) and biotic factor (vegetation coverage). Taking into account the mite communities, in total, 30 mite species were identified, with 1009 individuals and 18 immatures (10 species with 59 individuals, 5 immatures of Mesostigmata and 20 species with 950 individuals, 13 immatures of Oribatida). The investigated habitats from the tailing pond were grouped in five transects, with different degree of pollution, based on total metal loads. Taking into account of the connection between mites communities, abiotic factors and heavy metals, each transect were characterized through specific relationship. Using multivariate statistical analysis, we revealed that the occurrence of some Oribatida species was strongly correlated with vegetation coverage, soil pH and soil humidity, though concentrations of Cu, As, Mn, Ni and Zn also had an influence. Pb and Zn concentrations were shown to influence the occurrence of Mesostigmata mites. The heterogeneity of mites species richness at 2 m 2 scale was correlated with a metric related to the heterogeneity of heavy metals at the same scale.