Phosphorus Flux in Small Lakes from Different Natural-Climatic Zones

Factors of formation of phosphorus load on lakes of various landscapes (from tundra to steppe zone) are considered. The calculations of the balance model showed that the phosphorus load is predominantly determined by the conditional water exchange, specific catchment area, and runoff module. Statistical analysis demonstrated that phosphorus fluxes in lakes are determined by the cumulative impact of landscape (swamp and forest areas), climatic (annual precipitation, sum of active temperatures, duration of the vegetation period). Lakes from the tundra to forest-steppe zones are characterized by the low (mesotrophic) trophicity, while lake from the steppe zone reveals the high (eutrophic) trophicity. The factual phosphorus loads in lakes during the autumn homothermy were calculated and analyzed compared to the critical loads during the period of spring mixing.