The Sanjiang Plain of China, an important grain production base, is typical of ecosystems. In this study, 419 soil samples and a geostatistical method were used to estimate total SOC storage and to determine its pattern-controlling factors. The results from this study provide the most up-to-date knowledge on the storage and pattern of SOC in this plain, and the analysis conducted here could contribute to the determination of ecosystem carbon budgets and our understanding of ecosystem services.

Fossil planktic foraminifera and their geochemical composition are commonly used proxies in palaeoceanography. Our study with living specimens revealed that in the Fram Strait both Neogloboquadrina pachyderma and Turborotalita quinqueloba from the water column have lower δ18O and δ13C values than inorganically precipitated calcite/fossil tests from the sediment surface. These offsets indicate biological influence during calcification and a change of water column properties in the recent past.

Culture experiments based on a decoupled pH and CO32- chemistry indicate that the δ11B of the test of A. lessonii is related to pH whereas the B/Ca of the foraminiferal shells show a positive correlation with B(OH)4-/HCO3-. The latter observation suggests a competition between B(OH)4- and HCO3- of the culture media for B uptake into the test.

The CO2 sink strength of a temperate peatland in SE Scotland exhibited large inter-annual variability which was well-correlated to the length of the growing season. Mean winter air temperature explained 87% of the inter-annual variability in the sink strength of the following summer, indicating a phenological memory effect. Autotrophic respiration is thought to be dominant, but heterotrophic processes might have been enhanced during dry spells increasing the loss of CO2 to the atmosphere.

Extreme weather events can but do not have to cause extreme ecosystem response. Here, we focus on hazardous ecosystem behaviour and identify coinciding weather conditions. We use a simple probabilistic risk assessment and apply it to terrestrial ecosystems, defining a hazard as negative net biome productivity. In Europe, ecosystems are vulnerable to drought in the Mediterranean and temperate region, whereas vulnerability in Scandinavia is not caused by water shortages.

Around half of all pyrogenic carbon (charcoal+soot) derived from wildfires comes from semi-annual burning of tropical savannas. This pyrogenic carbon is significant because it is a component of global aerosols capable of modulating the greenhouse effect and is resistant to degradation. We use controlled field burns in northern Australian savannas to determine how much pyrogenic carbon is formed, how much of this is recalcitrant and how it is partitioned between ground residues and airborne soot.

We present a new technique to label organic matter (OM) at its place of formation by the application of 13C, 18O and 2H through the gaseous phase. The label diffused into leaves was incorporated into assimilates and was detected in plant tissues. This technique can be applied in soil sciences, e.g. to trace the decomposition pathways of soil OM inputs, or in plant physiology and palaeoclimatic reconstruction, e.g. to further investigate the origin of the 18O and 2H signal in tree ring cellulose.

Carbon dioxide transport between the terrestrial and aquatic systems was dominated by export from the near-stream riparian zone. Over the year, riparian export was highest during autumn storms and the spring snowmelt event. This resulted in high downstream export during these periods with vertical evasion from the stream surface accounting for 60% of the total stream water export, highlighting the importance of evasion to carbon export via the aquatic conduit.

In this manuscript, we present the results of iron uptake measured in the naturally iron-fertilized area during the Kerguelen Ocean and Plateau compared Study 2 cruise (KEOPS2). Iron uptake by bulk community and several size fractions (microplankton, pico-nanoplankton and bacteria) are presented, compared and discussed in the present paper. This work also presents first investigations on the potential competition between bacteria and phytoplankton for access to iron.

Plants are known as a source of methane (CH4), but the biochemical mechanisms involved in CH4 formation are still unknown. Employing 13C-labelled methionine clearly identified the sulfur-bound methyl group of methionine as a carbon precursor of CH4 released from lavender plants. When relating CH4 emission rates to dark respiration of intact plants, we found a molar CH4:CO2 emission ratio of 2.0 ±1.1 (pmol:µmol). After physical stress CH4 release rates greatly increased.

We question here is whether phytoplankton community growth rates respond to nutrient concentration in a similar manner to phytoplankton species composing the community, that is, following Monod's model. In situ marine community growth rates in relation to nutrient concentration and the behaviour of a simple multi-species community model show that community growth rate does not follow Monod's model. We observed here that this can be explained as a consequence of change in size structure.

Terrestrial inputs are considered the major driver of longitudinal patterns of nutrient concentration. Yet we show that longitudinal trends result from hydrological mixing with terrestrial inputs and in-stream processes. We challenge the idea that nutrient concentrations decrease downstream when in-stream net uptake is high. Conversely, in-stream processes can strongly affect stream nutrient chemistry and fluxes even in the absence of consistent longitudinal trends in nutrient concentration.

In the Scotia Sea, the zooplankton community shifting from a herbivorous to omnivorous diet strongly influences the chance of faecal pellets to reach the bottom. Faecal pellet flux was mainly a product of the vertically migrating and deeper-dwelling zooplankton in the iron-fertilized and iron-limited region respectively. The results demonstrate that the behaviour of the zooplankton community plays a critical role in controlling the quantity and quality of carbon exported in this area.

New nitrification inhibitor CP (chlorinated pyridine) application caused a significant decrease in yield-scaled N2O emissions in an intensively managed vegetable field, while biochar amendment had no significant influence on cumulative N2O emissions but significantly decreased soil pH and yield-scaled N2O emissions. Overall, taking environmental and economic benefits into consideration, CP application in the vegetable field was the best procedure for reducing the yield-scaled N2O emissions.

We investigated the evolution of inorganic carbon within landfast sea ice in Resolute Passage during the spring and summer melt period. Low TA and TCO2 concentrations observed in sea ice and brine were associated with the percolation of meltwater from melt ponds. Meltwater was continuously supplied to the ponds which prevented melt ponds from fully equilibrating with the atmospheric CO2 concentration, promoting a continuous uptake of CO2 from the atmosphere.