Spatial pattern of lithorheophile macrobenthos (by the example of a stream in Moscow region)

The distribution of lithorheophil macrobenthos was studied in the range of scales from decimeter (regions in the scope of one stone) up to seven kilometers on the basis of 153 quantitative samples from oligosaprobic stream in Moscow region. Community shows significant spatial heterogeneity even at the small scale: life forms inhabit different sides of each stone and different sites of the riffle depending on current. At the scale of tens and hundreds of meters (between different riffles, within one stream) spatial heterogeneity of benthos is low, distribution of common species is independent from each other and riffs are similar by community structure. At the scope of kilometers heterogeneity increase and the alterations of community appear due to changes in stream size. Seasonal differences of benthos distribution are mentioned. The impact of various environmental factors on the distribution of lithorheophile macrobenthos is discussed.