Soil invertebrates of a large industrial center

We studied soil-dwelling invertebrates in Nizhnekamsk city, which is a large industrial center (Tatarstan Republic, Russia). The Industrial Complex of Nizhnekamsk is situated nearby – petrochemical industry enterprises aggregation. We investigated soil macrofauna in three zones: sanitary-protective (impact), suburbs of the city (recreational) and in the city itself (residential zone). We sampled animals at 16 plots (meadows, pineries, limes and birch-woods). Samples included 128 soil-zoological ones, 1813 individuals of 24 taxones were caught. The highest taxonomical biodiversity in pedobionts was in residential zone (21 taxones were recorded), it was lower in impact and recreational zones – 19 and 25 taxones, respectively. The invertebrate number varied considerably (from 52 till 518 individuals/m2). The highest macrofauna number occurred at the open and forested plots of residential zones (a. o. insects domination in the meadows and earthworms – in the forests). Macrofauna numbers in impact and recreational zones were similar and lower, than in residential one. Pedobionts biomass varied considerably as well (from 4.4 till 149.3 g/ m2) and was also larger in residential zone. Earthworms and click-beetles dominated in macrofauna. Lumbricids biodiversity was the highest in forest phytocenoses of impact and recreational zones (6 species in each). Click-beetles biodiversity was higher in the meadows of impact and residential zones. In general, the abundance of pedobionts in Nizhnekamsk was higher than in the natural pine and deciduous forests of the Republic of Tatarstan. That was apparently due to non-distinctive soil conditions in coniferous biotopes and the manifestation of the protective reaction of organisms to anthropogenic impact. The latter was confirmed by multivariate analysis results. It showed that macrofauna structure significantly differed only between impact and residential zones.