Multi-year eddy-covariance measurements at a pre-alpine humid grassland site: Dataset overview, drought responses, and effects of land management

Abstract

Impacts of drought events on terrestrial ecosystems have been studied extensively in the last decades in light of the long-term human-induced global warming trend and the recent occurrence of severe heat waves and droughts across the globe. The 2003 European summer heat wave sparked high attention towards such events in Switzerland, where ecosystems were largely affected again by summer dry periods in 2015 and 2018. With a newly applied processing scheme of calculating fluxes of net ecosystem exchange of CO2, latent and sensible heat from eddy-covariance measurements, the impact of droughts on GPP and exchange of energy between land and atmosphere are investigated at a managed grassland site in Switzerland. The rate of primary production is considerably reduced under the influence of dry conditions. This effect is further intensified by grassland management. Evapotranspiration, on the other hand, seems to be unaffected by the lack of precipitation at the site.