Bogs of northern Eurasia represent a major type of peatland ecosystem and contain vast amounts of carbon, but carbon balance monitoring studies on bogs are scarce. The current project explores 6 years of carbon balance data obtained using the state-of-the-art eddy-covariance technique at a Finnish bog Siikaneva. The results reveal relatively low interannual variability indicative of ecosystem resilience to both cool and hot summers and provide new insights into the seasonal course of C fluxes.

We analyzed variability in diel nitrate patterns at three locations in a lowland stream. Comparison of time lags between monitoring sites with water travel time indicated that diel patterns were created by in-stream processes rather than transported downstream from an upstream point of origin. Most of the patterns (70 %) could be explained by assimilatory nitrate uptake. The remaining patterns suggest seasonally varying dominance and synchronicity of different biochemical processes.

Salt marshes and seagrass meadows ("blue carbon" habitats) can sequester and store high levels of organic carbon (OC), helping to mitigate climate change. In California blue carbon sediments, we quantified OC storage and exchange between these habitats. We find that (1) these salt marshes store about twice as much OC as seagrass meadows do and (2), while OC from seagrass meadows is deposited into neighboring salt marshes, little of this material is sequestered as "long-term" carbon.

We have measured the chemical composition of the carbonate shells of the parasitic foraminifera Hyrrokkin sarcophaga in order to test if it is influenced by the host organism (bivalve or coral). We find that both the chemical and isotopic composition is influenced by the host organism. For example strontium is enriched in foraminifera that grew on corals, whose skeleton is built from aragonite, which is naturally enriched in strontium compared to the bivalves' calcite shell.

Soil respiration is a large and temperature-responsive flux in the global carbon cycle. We found increases in microbial use of easy to degrade substrates enhanced the temperature response of respiration in soils layered as they are in situ. This enhanced response is consistent with soil composition differences in warm relative to cold climate forests. These results highlight the importance of the intact nature of soils rarely studied in regulating responses of CO₂ fluxes to changing temperature.

Conceptual models link microbes with the environment but are untested. We test a recent model using riverbed sediments. We exposed sediments to disturbances, going dry and becoming wet again. As the length of dry conditions got longer, there was a sudden shift in the ecology of microbes, chemistry of organic matter, and rates of microbial metabolism. We propose a new model based on feedbacks initiated by disturbance that cascade across biological, chemical, and functional aspects of the system.

Lakes act as important stores of organic carbon and inorganic sediment material. This study provides a first investigation into carbon and sediment accumulation and storage within an Arctic glacial lake from Far East Russia. It shows that major shifts are related to palaeoclimate variation that affects the development of the lake and its surrounding catchment. Spatial differences to other lake systems from other regions may reflect variability in processes controlled by latitude and altitude.

We investigated the response of a wetland plant community to elevated temperature conditions in a cushion bog on Tierra del Fuego, Argentina. We measured carbon dioxide fluxes at experimentally warmed plots and at control plots. Warmed plant communities sequestered between 55 % and 85 % less carbon dioxide than untreated control cushions over the main growing season. Our results suggest that even moderate future warming could decrease the carbon sink function of austral cushion bogs.

Climate change can change vegetation characteristics in grasslands with a potential impact on forage chemical composition and quality, as well as its use by ruminants. Using controlled conditions mimicking a future climatic scenario, we show that forage quality and ruminant digestion are affected in opposite ways by elevated atmospheric CO₂ and an extreme event (heat wave, severe drought), indicating that different factors of climate change have to be considered together.