Lipids provide crucial insight into the trajectory of ecological functioning in changing environments. We experimentally explore responses of lipid biomarker production in phytoplankton to projected changes in temperature, nutrients and pCO₂. Differential responses of lipid biomarkers indicate rearrangements of cellular carbon pools under future ocean scenarios. Such variations in lipid biomarker production would have important impacts on marine ecological functions and biogeochemical cycles.

We report the results from continuous year-round CO₂ observations from a sandy grassland in the Horqin Sandy Land using the eddy covariance technique. To quantify the diurnal, seasonal, and annual variation in net ecosystem CO₂ exchange, gross primary productivity, and ecosystem respiration and to identify the different scales of environmental factors and the underlying mechanisms, we also explored how the annual precipitation affects the net ecosystem CO₂ exchange and its components.

We looked at how terrestrial dissolved organic carbon (DOC) from the watersheds of four different lakes responded to both biodegradation (i.e., microbes) and photodegradation (i.e., sunlight). The traditional paradigm is that biodegradation is more important than photodegradation. Our research shows that, on short timescales (i.e., 7 d), sunlight is more important than microbes in degrading DOC. Interestingly, the lakes had different responses to sunlight based on their trophic status.

The release of CO₂ from soils, known as soil respiration, plays a major role in the global carbon cycle. However, the contributions of different soil depths or the sources of soil CO₂ have hardly been studied. We quantified the CO₂ production for different soil layers (up to 1.5 m) in three soil profiles for 2 years. We found that 90 % of CO₂ production occurs in the first 30 cm of the soil profile, and that the CO₂ originated from young carbon sources, as revealed by radiocarbon measurements.

Our results show that ocean acidification, warming, increased light exposure and reduced nutrient availability significantly reduce the growth rate but increase particulate organic and inorganic carbon in cells in the coccolithophore Emiliania huxleyi, indicating biogeochemical consequences of future ocean changes on the calcifying microalga. Concurrent changes in nutrient concentrations and pCO₂ levels predominantly affected E. huxleyi growth, photosynthetic carbon fixation and calcification.

An uneven supply of water and nutrients in soils often drives how plants behave. We observed that plants extract all their required nutrients from dry soil patches in sufficient quantity, provided adequate water is available elsewhere in the root zone. Roots in nutrient-rich dry patches facilitate the nutrient acquisition by extensive growth, water release, and modifying water retention in their immediate environment. The findings are valuable in managing nutrient losses in agricultural systems.

We use a model of the 2001–2015 tropical land carbon cycle, with satellite measurements of land and atmospheric carbon, to disentangle lagged and concurrent effects (due to past and concurrent meteorological events, respectively) on annual land–atmosphere carbon exchanges. The variability of lagged effects explains most 2001–2015 inter-annual carbon flux variations. We conclude that concurrent and lagged effects need to be accurately resolved to better predict the world's land carbon sink.

With distributed temperature sensing (DTS) we measured a vertical temperature profile in a forest, from the forest floor to above the treetops. Using this temperature profile we can see which parts of the forest canopy are colder (thus more dense) or warmer (and less dense) and study the effect this has on the suppression of turbulent mixing. This can be used to improve our knowledge of the interaction between the atmosphere and forests and improve carbon dioxide flux measurements over forests.

Mercury uptake by trees from the air represents an important but poorly quantified pathway in the global mercury cycle. We determined mercury uptake fluxes by leaves and needles at 10 European forests which were 4 times larger than mercury deposition via rainfall. The amount of mercury taken up by leaves and needles depends on their age and growing height on the tree. Scaling up our measurements to the forest area of Europe, we estimate that each year 20 t of mercury is taken up by trees.

The mobility of pyrogenic organic matter (PyOM) in soils is largely unknow, while it is a major and persistent component of the soil organic matter. With a soil column experiment, we identified that only a small proportion of PyOM can migrate through the soil, but its export is continuous. Aging and associated oxidation increase its mobility but also its retention in soils. Further, PyOM can alter the vertical mobility of native soil organic carbon during its downward migration.

Silicon is taken up by some plants to increase structural stability and to develop stress resistance and is rejected by others. To explore the underlying mechanisms, we used the stable isotopes of silicon that shift in their relative abundance depending on the biochemical transformation involved. On species with a rejective (tomato, mustard) and active (wheat) uptake mechanism, grown in hydroculture, we found that the transport of silicic acid is controlled by the precipitation of biogenic opal.

Here, data collected by BGC-Argo floats are used to investigate the origin of the suspended small-particle layer inferred from optical sensors in the oxygen-poor Black Sea. Our results suggest that this layer is at least partially composed of the microbial communities that produce dinitrogen. We propose that oxygen and the optically derived small-particle layer can be used in combination to refine delineation of the effective N₂-yielding section of the Black Sea and oxygen-deficient zones.

The Black Sea is 2000 m deep, but, due to limited ventilation, only about the upper 100 m contains enough oxygen to support marine life such as fish. This oxygenation depth has been shown to be decreasing (1955–2019). Here, we evidence that atmospheric warming induced a clear shift in an important ventilation mechanism. We highlight the impact of this shift on oxygenation. There are important implications for marine life and carbon and nutrient cycling if this new ventilation regime persists.

There has been a steady increase in interest in mining of deep-sea minerals in the eastern Pacific Ocean recently. The ocean state in this region is known to be highly influenced by rotating bodies of water (eddies), some of which can travel long distances in the ocean and impact the deeper layers of the ocean. Better insight into the variability of eddy activity in this region is of great help to mitigate the impact of the benthic ecosystem from future potential deep-sea mining activity.