Anthropogenic greenhouse gas emissions trigger complex climate feedbacks. Output form Earth system models provides a basis for related political decision-making. One challenge is to arrive at reliable model parameter estimates for the ocean biogeochemistry module. We illustrate pitfalls through which flaws in the ocean module are masked by wrongly tuning the biogeochemistry and discuss ensuing uncertainties in climate projections.

We investigated how nutrient availability affects seasonal timing of root growth and death in a Spanish savanna, adapted to a long summer drought. We found that nitrogen (N) additions led to more root biomass but number of roots was higher with N and phosphorus together. These effects were strongly affected by the time of year. In autumn root growth occurred after leaf production. This has implications for how we understand biomass production and carbon uptake in these systems.

PROFILE base cation weathering estimates using the directly measured XRPD mineralogy compared to different indirectly determined A2M mineralogies (regional versus site-specific) were overall similar. However, the underlying contribution from different minerals to the overall rates differed. Descriptions of the dissolution rate kinetics of the plagioclase mineral group as well as major K-bearing minerals (K feldspars and micas) should be improved for future soil and forest management studies.

Researchers from the University of Western Australia's Oceans Institute are studying large tides (up to 12 m range) that occur in the Kimberley region of Australia. These tides flush coral reefs with water rich in nutrients, which supports the growth of reef organisms. In this paper, we show how tidal cycles and seasons control nutrient availability on reefs. This study is among the first published accounts of reefs and water quality data in the remote and pristine Kimberley region.

In natural coastal wetlands, high supplies of marine sulfate suppress methane production. We found these natural methane suppression mechanisms to be suspended by humane interference in a brackish wetland. Here, diking and freshwater rewetting had caused an efficient depletion of the sulfate reservoir and opened up favorable conditions for an intensive methane production. Our results demonstrate how human disturbance can turn coastal wetlands into distinct sources of the greenhouse gas methane.

In a context of global changes, modeling and predicting the dynamics of soil carbon stocks in forest ecosystems are vital but challenging. Yasso07 is considered to be one of the most promising models for such a purpose. We examine the accuracy of its prediction of soil carbon dynamics over the whole French metropolitan territory at a decennial timescale. We revealed how the bottleneck in soil carbon modeling is linked with the lack of knowledge on soil carbon quality and fine-root litter.

An approach using bio-optical field and ocean color (Sentinel-3A OLCI) data combined with inversion models allowed for the first time an assessment of phytoplankton response (changes in taxonomy, pigment composition and physiological state) to a large hurricane-related floodwater perturbation in a turbid estuary. The study revealed the transition in phytoplankton community species as well as the spatiotemporal distributions of phytoplankton diagnostic pigments in the floodwater-impacted bay.

The trace gases NO and HONO are crucial for atmospheric chemistry. It has been suggested that biological soil crusts in drylands contribute substantially to global NO and HONO emissions, based on empirical upscaling of laboratory and field observations. Here we apply an alternative, process-based modeling approach to predict these emissions. We find that biological soil crusts emit globally significant amounts of NO and HONO, which also vary depending on the type of biological soil crust.

High primary production in the Peruvian upwelling system is followed by rapid heterotrophic utilization of organic matter and supports the formation of one of the most intense oxygen minimum zones (OMZs) in the world. Here, we estimated vertical fluxes of oxygen and dissolved organic matter (DOM) from the surface to the OMZ. Our results suggest that DOM remineralization substantially reduces oxygen concentration in the upper water column and controls the shape of the upper oxycline.

In the Sahel region during the wet season, CO₂ and NO are released to the atmosphere, and NH3 is deposited on the soil. During the dry season, processes are strongly reduced. This paper shows the temporal variation in these soil–atmosphere exchanges of trace gases for 2 years, their sharp increase when the first rains fall onto dry soils, and how microbial processes are involved. We use a modelling approach, which is necessary when continuous measurements are not possible in remote regions.

A strong El Niño event occurred in the Peruvian coastal region in 2015–2016, during which higher sea surface temperatures co-occurred with significantly lower sea-to-air fluxes of nitrous oxide, an important greenhouse gas and ozone depletion agent. Stratified water column during El Niño retained a larger amount of nitrous oxide that was produced via multiple microbial pathways; and intense nitrous oxide effluxes could occur when normal upwelling is resumed after El Niño.