Single-celled living calcareous planktic foraminifera data across the Mediterranean Sea suggest that stratification of the surface water column, food availability, temperature, and seawater carbonate chemistry are the main factors controlling their distribution and mass. Increasing temperature, salinity, surface ocean stratification, and trophic conditions could be the causes of reduced abundance, diversity and species-specific changes in calcification in planktic foraminifera.

We measured concentrations of the greenhouse gases methane and nitrous oxide in rivers from the western Congo Basin (Republic of Congo). All rivers studied were strong sources of methane to air but they ranged from minor sources to minor sinks for nitrous oxide. Our estimated emissions to air agreed with existing estimates for sub-Saharan African rivers, supportive of the growing consensus that African river systems are a major contributor to the global freshwater source of greenhouse gases.

The Arctic Ocean, especially the Siberian shelves, overlays large areas of subsea permafrost that is degrading. We show that methane with a biogenic origin is emitted from this permafrost. At locations where bubble plumes have been observed, methane can escape oxidation in the surface sediment and rapidly migrate through the very shallow water column of this region to escape to the atmosphere, generating a positive radiative feedback.

Complex plant–soil interactions in the hydrological cycle of a Mediterranean cork oak ecosystem are investigated with stable water isotopes. Trees largely foster infiltration due to altered microclimatic conditions below crowns but compete with understorey plants for the same water source in deeper soil layers. The presence of understorey plants does not alter water losses compared to bare soil, but water utilization for carbon sequestration and nitrogen fixation is largely increased.

Spruces worldwide have been classified into groups based on morphological similarity and phylogenetic affinity. However, climatic influences on the divergence of spruces remain unknown. Using data from 3388 sites of spruces worldwide, we found that temperature parameters and precipitation parameters tended to be the main driving factors for the primary divergence of spruce phylogeny and morphology, respectively.

The marine biological carbon pump is dominated by the vertical transfer of particulate organic carbon (POC) from the surface ocean to its interior. In this study, we explore the impacts of a variable composition of this organic matter using a global ocean biogeochemical model. We show that accounting for a variable lability of POC increases POC concentrations by up to 2 orders of magnitude in the ocean's interior. Furthermore, the amount of carbon that reaches the sediments is twice as large.

This paper provides the formalism and examples of how observation operators can be used, in combination with data assimilation or retrieval techniques, to better ingest satellite products in a manner consistent with the dynamics of the Earth system expressed by models.

We measured the abundance of a nitrogen (N) isotope (¹⁵N) in two subtropical forests in China to study the cycling of input N (deposition and addition). Plant leaves in both forests were ¹⁵N-depleted relative to the atmospheric standard, likely as an imprint from ¹⁵N-depleted deposition. Plant ¹⁵N changed into ¹⁵N of the added N, indicating incorporation of N into plants. Thus, interpretations of ecosystem ¹⁵N from high-N-deposition regions need to include data on the ¹⁵N deposition signature.

The subsurface chlorophyll maximum layer (SCML) forms near the nitracline. By incorporating a piecewise function for the approximate Gaussian vertical profile of chlorophyll, we derive analytical solutions of a specified nutrient–phytoplankton model. Nitracline depth is deeper than SCML depth, and a thinner SCML corresponds to a steeper nitracline. A higher light attenuation coefficient leads to a shallower but steeper nitracline. Nitracline steepness is independent of surface light intensity.

We modeled, for 26 European countries, the C budget and fluxes of the main forest pools from 2000 to 2030 under different management scenarios. Our findings show an incipient aging process for the existing forests, but specific conditions, such as the harvest rate and the current age structure, may have different impacts on the country-specific evolution of biomass stock. This provides a useful framework for more detailed analyses of the mitigation potential of the forest sector.

This study assesses the impact of ocean acidification on phytoplankton and its synthesis of the climate-active gas dimethyl sulfide (DMS), as well as its modulation, by two contrasting light regimes in the Arctic. The light regimes tested had no significant impact on either the phytoplankton or DMS concentration, whereas both variables decreased linearly with the decrease in pH. Thus, a rapid decrease in surface water pH could alter the algal biomass and inhibit DMS production in the Arctic.

Amazonian podzol soils store huge amounts of carbon and play a key role in transferring organic matter to the Amazon River. We modelled their formation by constraining both total carbon and radiocarbon. We found that the most waterlogged zones of the podzolized areas are the main source of dissolved organic matter found in the river network. The genesis time calculated considering the more likely settings runs to around 15–25 and 150–250 kyr for young and old podzols, respectively.

The C-GEM generic reactive-transport model is applied to each tidal estuary of the US East Coast. Seasonal simulations are performed, which allows the understanding and quantification of the effect of the estuarine filter on the lateral fluxes of carbon coming from rivers.

Nutrient-limited phytoplankton are capable of first taking up the limiting nutrient and continuing to take up non-limiting nutrients after the exhaustion of the limiting nutrient, and then taking up the limiting nutrient rapidly when it is available due to mixing of the water column. We refer to this process as phytoplankton sequential nutrient uptake. Our results showed the sequential nutrient uptake, a process to maintain the phytoplankton nutrient stoichiometry and high primary productivity.

We measured carbon and nitrogen isotope ratios (¹³C : ¹²C and ¹⁵N : ¹⁴N) in peat cores in a northern Minnesota bog to understand how climate, vegetation type, and decomposition affected C and N budgets over the last 9000 years. ¹³C : ¹²C patterns were primarily influenced by shifts in temperature, peatland vegetation and atmospheric CO₂, whereas tree colonization and upland N influxes affected ¹⁵N : ¹⁴N ratios. Isotopic markers provided new insights into long-term patterns of CO₂ and nitrogen losses.

We conducted a field manipulation experiment by redistributing 67 % of dry-season rainfall into the wet season while keeping the annual rainfall unchanged in a subtropical forest. Soil net nitrification and N mineralization rates were decreased by 13–20 % in the dry season and increased by 50 % with an accelerated NO₃ leaching in the wet season. Functional microbial gene abundance and microbial biomass were the main factors affecting the N-process responses to the rainfall seasonality changes.

We present the Joint Research Centre Two-stream Inversion Package (JRC-TIP) for retrieval of variables characterising the state of the vegetation–soil system. The system provides a set of land surface variables that satisfy all requirements for assimilation into the land component of climate and numerical weather prediction models.

Mangroves take up more carbon (C) than any other ecosystems, but > 50 % of this C is missing. The forest loses organic C to the surrounding waters, which might be rapidly transformed into inorganic C. Previous studies focused on organic C could have missed this important sink. We examined the sources and sinks of dissolved C in two mangrove estuaries, and confirmed that ca. 90 % of the total dissolved mangrove-derived C flux flowing out of the estuaries was inorganic C.

Significantly high total hydrolysable amino acid concentrations and yields were observed in the East/Japan Sea of deep-water formation, indicating the convection of margin-derived bioavailable dissolved organic matter to deep waters. Our observational results suggest that the effective transport of bioavailable DOM to the deep ocean can be significantly sensitive to changes in the deep-water renewal rates and in temperature of the surface ocean, linked to global warming.