We compare how two global circulation models simulate biological production over the year with observations. Note that models simulate the range of biological production and biomass well but fail with regard to timing and regional structures. This is probably because the physics in the models are wrong, especially vertical processes such as mixed layer dynamics.

Under UVR and stratification,the commensalistic algae-bacteria interaction was strengthened in the high-UVR lake, where excretion of organic carbon rates exceeded the bacterial carbon demand,but did not occur in the low-UVR lake.The greater UVR damage to algae and bacteria and the weakening of their commensalistic interaction found in the low-UVR lake indicates these lakes would be especially vulnerable to UVR. These results have implications for the C cycle in lakes of the Mediterranean region.

This article describes a low-cost, easily set-up ocean acidification simulation system that reliably mimics the effects of elevated atmospheric carbon dioxide on seawater chemistry. The accessible design of this system, along with our suggestions for the validation of pH control and characterisation of seawater chemistry, will enable researchers on a limited budget to generate high-quality, repeatable data documenting the response of marine organisms to ocean acidification.

Trace metal analysis of suspended and settling particles and underlying sediment was undertaken to elucidate the source to sink progression of the particulate trace metal pool near Kerguelen Island (Southern Ocean). Findings indicate that the Kerguelen Plateau is a source of trace metals via resuspended shelf sediments, especially below the mixed layer. However, glacial/fluvial runoff into shallow coastal waters is an important mode of fertilisation to areas downstream of Kerguelen Island.

Global climate change may increase the litter inputs in some ecosystems impacting the soil–plant system functioning. We added litter, to the 10–20 cm subsoil layer of a steppe community at different rates. Small litter additions had no effect on the stoichiometry, whereas the highest additions (not realistic compared to the future predictions) modified the system slightly. It suggests that the grassland studied here is resilient to more plausible inputs in terms of stoichiometric functioning.

Significant changes in the microbial community were observed during 180-day incubations of soil samples from a wetland where Feammox activity has been observed previously, as well as in a continuous flow membrane reactor. Results indicate that the dominant microbial species, an uncultured Acidimicrobiaceae bacterium A6 belonging to the Acidimicrobiaceae family, plays a key role in this anaerobic biological process using ferric iron as an electron acceptor while oxidizing ammonium to nitrite.

Different observational-based estimates of CO2 uptake and resulting acidification of the Mediterranean Sea vary widely. A new study finds that even the smallest of those are an upper limit because the approach used assumes air-sea CO2 equilibrium. Then with a lower limit from new fine-scale numerical model simulations, the authors bracket Mediterranean Sea CO2 uptake and acidification rates. They conclude that its rate of surface acidifcation is much like that for typical ocean waters.

The combination of NBPT and DCD with basal rather than supplemental fertilizer urea would be an effective practice for reducing N2O emission during the wheat growth season. Additionally, application of nitrophosphate, instead of urea, is an optimum agricultural strategy for reducing N2O emission and for increasing crop yield and nitrogen use efficiency for wheat cultivation in the soils of the North China Plain.

Soil microbial respiration is a central process in the terrestrial carbon (C) cycle. In this study, I tested the effect of the carbon-to-nitrogen (C:N) ratio of soil litter layers on microbial respiration in absolute terms and per unit microbial biomass C. For this purpose, a global dataset on microbial respiration per unit microbial biomass C – termed the metabolic quotient (qCO2) – was compiled form literature data. It was found that the qCO2 in the soil litter layers was positively correlated

Recent papers suggest a slow-down in the natural uptake of anthropogenic CO2. We analyse recent trends in atmospheric concentration and known inputs to test for such a slow-down. We see, rather, an increase in uptake compared to a simple response to changing CO2 concentration. Using atmospheric models and statistical techniques we isolate this increased uptake to the northern temperate and boreal continents during summer, suggesting a stronger growing season.

Phytoliths contain occluded organic compounds called phytC. The nature and location of phytC in biogenic silica structures is poorly understood. Here, we reconstructed the 3-D structure of phytoliths using 3-D Xray microscopy. We further evidenced a pool of phytC, continuously distributed in the silica structure, using nanoscale secondary ion mass spectrometry (NanoSIMS). Our findings allowed the re-evaluation of previous suggestions regarding phytC quantification and environmental meaning.

Long-term mean monthly fluxes of carbon and nutrients to the surface layer of the Iceland Sea are presented. From these fluxes we estimate primary production based on newly added nitrate (i.e. new production) and net community production (NCP). The annual new production in the Iceland Sea is estimated to 0.45±0.09mol N/m2/yr, and the net annual NCP to 7.3±1.0mol C/m2/yr. The typical C:N ratio during biological uptake is 9.0, challenging the Redfield C:N as the conversion factor in the area.