Substance and energy flows formed by the emergence of amphibiotic insects across the water–air boundary on the floodplain lakes of the Volga River

Abstract

Substance flow across the water–air boundary on the floodplain Lake Holodnoe (Saratov oblast) is generally formed by the Culicomorpha (76.1%) and accounts for 0.35 g/m² of the lake area per year. The energy flow amounts to 1.87 kcal/m², and most of it accounts for the second half of summer and autumn. Annual removal of biogenic elements is 0.18 g/m² for carbon, 0.04 g/m² for nitrogen, and 0.004 g/m² for phosphorus. The greatest contribution to flows of substance and energy is brought by large species of chironomids, as well as chaoborids and medium-sized chironomids, which produce several generations within a year and reach high abundance at a larval stage. Other floodplain lakes of the Volga River with similar biotopical features and species composition of amphibiotic insects are characterized by a quantitatively similar level of exchange processes with adjacent land ecosystems across the water–air boundary.