Plant carbon (C) content is critical to the assessment of the global C cycle. Our results showed that the global average C contents in organs were significantly lower than a canonical value of 50 %. Plant C content tended to decrease with increasing latitude, and life form explained more variation than climate. Our findings suggest that specific C content values of different organs and life forms should be incorporated into the estimations of regional and global vegetation biomass C stocks.

When drained, peatlands degrade and release large quantities of CO₂, thereby contributing to global warming. Do land use or the chemical composition of peat control the rate of that release? We studied 21 sites from the temperate climate zone managed as croplands, grasslands, or forests and found that the CO₂ release was high, but only slightly influenced by land use or peat composition. Hence, only keeping peatlands in their natural state prevents them from becoming strong CO₂ sources.

The direct impact of rainfall on groundwater at Mt. Fuji, the largest volcanic mountain in Japan, was elucidated by multiple analyses including microbial DNA. Bacterial abundance and DNA not only supported the findings on the movement of groundwater obtained from chemical analyses but also elucidated chemically unseen flow. Evidence of piston flow in deep groundwater was first shown through changes in archaeal density and diversity. Microbial analysis extends our understanding of groundwater.

Our paper highlights the importance of dual-nutrient management: nitrogen (N) and phosphorus (P) in lakes with cyanobacterial harmful algal blooms. Taihu Lake (China) experiences seasonal blooms due to increased input of N and P from field runoff. The main process investigated in our study, nitrification, is important for N removal through denitrification. We show that nitrification is less efficient during the blooms, due to competition for nutrients between N microbes and cyanobacteria.

This study compares the response of phytoplankton growth in the northwest Pacific to those in the Yellow Sea. In general, larger positive responses of phytoplankton induced by combined nutrients (in the subtropical gyre of the northwest Pacific) than those induced by a single nutrient (in the Kuroshio Extension and the Yellow Sea) from the dust are observed. We also emphasize the importance of an increase in bioavailable P stock for phytoplankton growth following dust addition.

Nitrous oxide (N₂O) is an important and strong greenhouse gas in the atmosphere and part of climate. N₂O is produced by microbes in terrestrial and aquatic ecosystems. The properties of each specific molecule can be used to determine the source. We implemented continuous measurements of N₂O during incubation of denitrifying bacteria and believe that similar experiments will lead to a better understanding of N₂O turnover and on the biotic mechanisms behind greenhouse gas exchange of the globe.

Past seawater temperatures can be reconstructed using magnesium / calcium ratios of biogenic carbonates. As temperature increases, so does magnesium. Here we show that for these Arctic/subarctic coralline algae, anatomy is the first control on Mg / Ca, not temperature. When using coralline algae for temperature reconstruction, it is first necessary to check for anatomical influences on Mg / Ca.

This study is a preparatory work for inoculating artificial biological soil crusts (biocrusts). The response of the physiological characteristics and regenerative capacity of three mosses to storage temperatures were studied. Results showed that different temperature significantly influenced the physiological characteristics of the mosses, which caused alteration in their regenerative capacity. More focus should therefore be on the state of moss inocula when restoring biocrusts by inoculation.

This work demonstrates that lysis by viruses facilitates the transfer of nitrogen to phytoplankton in the ocean, and thus viruses are key players in nitrogen cycling in the oceans and in maintaining oxygen production by marine primary producers.

Dissolved organic matter (DOM) fate in soils can be impacted by frequent wet–dry cycles that occur in the subsoil environment. This study provides direct evidence that wet–dry cycles altered both composition and spatial distribution of organic carbon on a complex soil matrix. Therefore transformation of soils with a wet environment to higher fluctuation in soil moisture, as predicted by climate models, may alter the interactions between DOM and soil surfaces.

Calcifying phytoplankton play an import role in long-term CO₂ removal from the atmosphere. We therefore studied the ability of a representative species to continue sequestrating CO₂ under future climate conditions. We show that CO₂ sequestration is negatively affected by both an increase in temperature and the resulting decrease in nutrient availability. This will impact the biogeochemical cycle of carbon and may have a positive feedback on rising CO₂ levels.

Winter carbon dioxide (CO₂) respiration from soils is a significant and understudied component of the global carbon (C) cycle. In this study, we were able to show with a field campaign and a model how windy (advective) conditions can affect the usually slow (diffusive) transport of CO₂ from soils and out of snowpacks. This research is important to help with understanding winter CO₂ dynamics, especially for continued accurate accounting of the annual global C cycle.

We show that post-depositional formation of iron(II) phosphate as vivianite strongly alters the phosphorus record in sediments of the Bornholm Basin (Baltic Sea). These minerals began to precipitate in the lake sediments just after the last lake–marine transition ~ 7.5 kyr BP, migrated downwards and are now a stable feature. Formation of vivianite may affect sedimentary phosphorus records in other systems as well. This should be considered when using such records to reconstruct past environments.

Using satellite technology and a life-size experiment, we analysed the impact of oyster reefs on mats of microscopic algae that develop within coastal mudflats. We showed that the relationship between microalgae and oysters is not limited to a one-way process where microalgae are a food source to oysters, but that oysters also promote microalgae mats development, presumably by providing nutrients to them. This might yield new insights into coastal ecosystem management.

Using a dynamic vegetation model, we demonstrate that fire occurrence is the main determinant factor of vegetation changes along the Amazon–Cerrado border, followed by nutrient limitation and interannual climate variability. Although we simulated more than 80 % of the variability of biomass in the transition zone, in many places the simulated biomass clearly does not match observations. The accurate representation of the transition is important for understanding the savannization of the Amazon.

Emission via bubbling, i.e. ebullition, is one of the main CH₄ emission pathways from wetlands to the atmosphere, yet it is still coarsely represented in wetland CH₄ models. In this study three ebullition modelling approaches are evaluated. Modeled annual CH₄ emissions were similar, whereas temporal variability in CH₄ emissions varied an order of magnitude between the approaches. Hence realistic description of ebullition is needed when models are compared to and calibrated against measurements.

Our paper investigates soil organic carbon and nitrogen in permafrost soils on Sobo-Sise Island and Bykovsky Peninsula in the north of eastern Siberia. We collected and analysed permafrost soil cores and upscaled carbon and nitrogen stocks to landscape level. We found large amounts of carbon and nitrogen stored in these frozen soils, reconstructed sedimentation rates and estimated the potential increase in organic carbon availability if permafrost continues to thaw and active layer deepens.