Effect of Elevation Gradient on the Structure of Aquatic Communities in the Vangyr River Basin, the Subpolar Urals

摘要

The effect of elevation gradient on characteristics of aquatic communities has been studied in the basin of the Vangyr River, a third-order tributary of the Pechora River. The results show that the orders of amphibiotic insects characteristic of the rhithron zone prevail in the zoobenthos. The composition of hydrobiont fauna slightly changes with increasing distance from the upper reaches of the river to its mouth, but the main insect families remain the same. The structure of fish community largely depends on the position of river segments and lakes in the elevation gradient. Only one species-Arctic char, a probable glacial relict-has been found at the sources of the Vangyr. Fish communities in many mountain lakes are monospecific. The ichthyofauna becomes gradually enriched as the river mouth is approached: there appears another glacial relict (peled) and anadromous and semianadromous species (Atlantic salmon and Siberian whitefish).