Abstract
The study of Staphylinidae fauna in the Ob river flood plain was conducted from May to September 2010, and in the Irtysh flood plain from May to August, in 2013–2014. Pitfall traps together with hand collecting and soil sample sorting were used. The maximal bio-diversity (32 species, with Philonthus decorus Grav. dominating) and density of rove beetles were registered in the small-leaved forests of the Ob flood plain. In the Irtysh river flood plain rove beetles demonstrated maximal bio-diversity (16 species) in willow-shrub, Gymnusa brevicollis Grav., Philonthus albipes Grav. and Philonthus agilis Grav. dominating. Most Staphylinidae prefer wet and warm places, like an inner part of fluvial sediments or upper level of forest litter. In the forests’ ecosystems the peak of activity takes place between the beginning of June and mid-July, but it shifts to the end of summer in the wetlands of the Ob and Irtysh flood plain.