dryflux

The CO2 emissions from dry freshwater systems represent a so far overlooked process in the global carbon cycle. Recent research indicates that drying and rewetting of freshwater sediments creates hot spots of carbon mineralization and thus CO2 emissions, which are probably relevant on a global scale (Gómez-Gener et al., 2016; Reverey et al., 2016; Von Schiller et al., 2014). However, existing knowledge is scarce and mainly based on regional studies from e.g. U.S.A. (Gallo et al., 2014) or Spain (Gómez-Gener et al., 2016), investigating specific systems (either lotic or lentic), though underlying biogeochemical processes are assumed to be globally valid (Reverey et al., 2016).Habitats with exposed sediments include ephemeral rivers and ponds as well as shallow sediments of lakes and reservoirs with large water level fluctuations. We hypothesize that CO2 emissions from these sites is higher under dry conditions compared to the flooded phase and relevant on a global scale. To test this hypothesis we want to quantify CO2 emissions from dry sediments in different types of dry habitats all over the globe (<100 sites).The CO2 flux shall be measured by a simple static closed chamber approach. These flux measurements will be accompanied by a number of basic measurements (like temperature, sediment moisture, etc.) and site data to assess potential regulating factors. If the data allow, we would also check the importance of CH4 and N2O emissions from dry sediments. We would like to generate a global dataset with the help of a number of selected international collaborators. In case of time restrictions, inclusion of more systems is more important than replicates within systems. The collection and interpretation of the dataset shall lead to a joint publication. More information: http://www.ufz.de/dryflux/index.php?en=42266