Emissions of greenhouse gases from Lake Neusiedl, a shallow steppe lake in Eastern Austria

Abstract

Greenhouse gas emissions of Lake Neusiedl, the westernmost European shallow steppe lake, were analysed to identify differences between the seasons of the years and between different locations in the pelagic zone and reed belt. Emissions of CO2, CH4 and N2O were measured in gas samples that had been recovered from the gas space of floating chambers operated as closed systems. Sampling periods covered all seasons except winter. Scaled up to the whole lake area (320 km2), the diffusive emissions of spring, summer and autumn totalled to about 79,500 t CO2e, disregarding bubble emissions, winter emissions and plant-mediated emissions. The emission sum consisted of about 57,000 t CO2, 760 t CH4, and 12 t N2O. Approximately one-third of the methane and carbon dioxide emissions originated in the pelagic zone and two-thirds in the reed belt (without plant emissions) whereas nitrous oxide emissions were similar in these two zones. An estimate of ebullitive emissions resulted in additional 1,765 t CH4 that predominantly originated in or near the reed belt from spring to autumn.