The understanding of surface water methane production in the world oceans is still poor. By combining field studies and incubation experiments, our investigations suggest that zooplankton contributes to subthermocline methane enrichments in the central Baltic Sea by methane production within the digestive tract of copepods and/or by methane production through release of methane precursor substances into the surrounding water, followed by microbial degradation to methane.

Southeast Asian peat-draining rivers are potentially strong sources of carbon to the atmosphere due to the large amounts of organic carbon stored in those ecosystems. We present the first assessment of CO₂ emissions from the Rajang River, the largest peat-draining river in Malaysia. The peatlands’ influence on the CO₂ emissions from the Rajang River was smaller than expected, probably due to their proximity to the coast. Therefore, the Rajang was only a moderate source of CO₂ to the atmosphere.

By combining taxonomy and geochemistry, we corroborated the described paleoenvironments from a Neogene fossiliferous deposit of South America. Shark teeth specimens were used for taxonomic identification and as proxies for geochemical analyses. With a multidisciplinary approach we refined the understanding about the paleoenvironmental setting and the paleoecological characteristics of the studied groups, in our case, for the bull shark and its incursions into brackish waters.

Weather, humans, and vegetation control the occurrence of fires. In this study we find that global fire–vegetation models underestimate the strong increase of burned area with higher previous-season plant productivity in comparison to satellite-derived relationships.

Canopy structural and leaf photosynthesis parameterizations are often fixed over time in Earth system models and represent large sources of uncertainty in predictions of carbon and water fluxes. We develop a moving window nonlinear optimal parameter inversion framework using constraining flux and satellite reflectance observations. The results demonstrate the applicability of the approach for error reduction and capturing the seasonal variability of key ecosystem parameters.

We have compared global carbon budgets calculated from numerical inverse models and CO₂ observations, and evaluated how these systems reproduce vertical gradients in atmospheric CO₂ from aircraft measurements. We found that available models have converged on near-neutral tropical total fluxes for several decades, implying consistent sinks in intact tropical forests, and that assumed fossil fuel emissions and predicted atmospheric growth rates are now the dominant axes of disagreement.

We evaluate the effects of climate change and biogeochemical forcing evolution on the nutrient and plankton cycles of the Mediterranean Sea for the first time. We use a high-resolution coupled physical and biogeochemical model and perform 120-year transient simulations. The results indicate that changes in external nutrient fluxes and climate change may have synergistic or antagonistic effects on nutrient concentrations, depending on the region and the scenario.

We assess the impact of warming on nitrogen fixation in three key Mediterranean macrophytes by experimentally measuring sediment nitrogen fixation rates at current and projected seawater temperature by 2100 under a scenario of moderate greenhouse gas emissions. The temperature dependence of nitrogen fixation could potentially increase rates by 37 % by the end of the century, with important consequences for primary production in coastal ecosystems.

Combined measurement of CO₂ / O₂ fluxes in tree stems suggested that on average 41 % of the respired CO₂ was not emitted locally to the atmosphere. This finding strengthens the recognition that CO₂ efflux from tree stems is not an accurate measure of respiration. The CO₂ / O₂ fluxes did not vary as expected if CO₂ dissolution in the xylem sap was the main driver for the CO₂ retention. We suggest the examination of refixation of respired CO₂ as a possible mechanism for CO₂ retention.