Carbon dioxide fluxes have been measured seasonally in four plant species in a Mediterranean non-tidal salt marsh, highlighting the high carbon removal potential that these species have. Carbon dioxide and methane emissions from soil showed high variability among the habitats studied, and they were generally higher than those observed in tidal salt marshes. Our results are important for making more accurate predictions regarding carbon emissions from these ecosystems.

The 2022 fire season had a huge impact on European temperate forest, with several large fires exhibiting prolonged soil combustion reported. We analyzed CO and CO₂ concentration recorded at nearby atmospheric towers, revealing intense smoldering combustion. We refined a fire emission model to incorporate this process. We estimated 7.95 Mteq CO₂ fire emission, twice the global estimate. Fires contributed to 1.97 % of France's annual carbon footprint, reducing forest carbon sink by 30 % this year.

Machine learning (ML) models are gaining popularity in biogeosciences. They are applied as gap-filling methods and used to upscale carbon fluxes to larger areas. Here we use explainable artificial intelligence (XAI) methods to elucidate the performance of machine learning models for carbon dioxide fluxes in boreal forests. We show that statistically equal models treat input variables differently. XAI methods can help scientists make informed decisions when applying ML models in their research.

Atmospheric microorganisms are a small fraction of Earth's microbiome, with bacteria being a significant part. Aerosolized bacteria are airborne for a few days, encountering unique chemical and physical conditions affecting stress levels and survival. We explore chemical and microphysical conditions bacteria encounter, highlighting potential nutrient and oxidant limitations and diverse effects by pollutants, which may ultimately impact the microbiome's role in global ecosystems and biodiversity.

Forests are seen as good for climate. Yet, in areas with snow, trees break up the white snow surface and absorb more sunlight than open areas. This has a warming effect, negating some of the climate benefit of trees. We studied two site pairs in Finland, both with an open peatland and a forest. We found that the later the snow melts, the more extra energy the forest absorbs as compared to the peatland. This has implications for the future, as snow cover duration is affected by global warming.

The DO₃SE-Crop model extends the DO₃SE to simulate ozone's impact on crops with modules for ozone uptake, damage, and crop growth from JULES-crop. It's versatile, suits China's varied agriculture, and improves yield predictions under ozone stress. It is essential for policy, water management, and climate response, and it integrates into Earth system models for a comprehensive understanding of agriculture's interaction with global systems.

Mineral fertilization led to increases in total P, available P, high-activity inorganic P fractions, and organic P but reduced the abundance of P-cycling genes by decreasing soil pH and increasing P in bulk soil. Straw retention enhanced organic carbon, total P, and available P concentrations in water-extractable colloids (WECs). Abundances of the phoD gene and phoD-harboring Proteobacteria in WECs were elevated under straw retention, suggesting an increase in P-mineralization capacity.

Mangrove carbon storage in the Red Sea is lower than average due to challenging growth conditions. We collected mangrove soil cores over multiple seasons to measure greenhouse gas (GHG) flux of carbon dioxide and methane. GHG emissions are a small offset to mangrove carbon storage overall but punctuated by periods of high emission. This variation is linked to environmental and soil properties, which were also measured. The findings aid understanding of GHG dynamics in arid mangrove ecosystems.

Betula pendula is a widespread birch tree species containing ice nucleation agents that can trigger the freezing of cloud droplets and thereby alter the evolution of clouds. Our study identifies three distinct ice-nucleating macromolecule (INM) aggregates of varying size that can nucleate ice at temperatures up to –5.4°C. Our findings suggest that these vegetation-derived particles may influence atmospheric processes, weather, and climate more strongly than previously thought.

When microbes consume carbon within soils, it is important to know how much carbon is respired and lost as carbon dioxide versus how much is used to make new biomass. We used a new approach of monitoring carbon dioxide and oxygen to track the fate of consumed carbon during a series of laboratory experiments where sugar was added to moistened soil. Our approach allowed us to estimate how much sugar was converted to dead microbial biomass, which is more likely to be preserved in soils.

Ocean alkalinity enhancement (OAE) is a negative emission technology which may alter marine communities and the particle export they drive. Here, impacts of carbonate-based OAE on the flux and attenuation of sinking particles in an oligotrophic plankton community are presented. Whilst biological parameters remained unaffected, abiotic carbonate precipitation occurred. Among counteracting OAE’s efficiency, it influenced mineral ballasting and particle sinking velocities, requiring monitoring.

We reconstructed drought conditions for the past 200 years for central and eastern parts of Europe (Romania) using δ¹⁸O in oak tree ring cellulose from Romania, revealing periods of both extreme wetness (e.g., 1905–1915) and dryness (e.g., 1818–1835). The most severe droughts occurred in the 19th and 21st centuries, likely linked to large-scale atmospheric circulation. This research highlights the potential of tree rings to improve our understanding of long-term climate variability in Europe.

This study provides the first evidence for biogeochemical cycling of supraglacial dissolved organic matter (DOM) in meltwater flowing through the porous crust of weathering ice that covers glacier ice surfaces during the melt season. Movement of water through the weathering crust is slow, allowing microbes and solar radiation to alter the DOM in glacial meltwaters. This is important as supraglacial meltwaters deliver DOM to downstream aquatic environments.

Accurate radiation data are essential for understanding ecosystem functions and dynamics. Traditional large-scale data lack the precision needed for complex terrain. This study introduces a new model, which accounts for sub-daily direct and diffuse radiation effects caused by terrain features, to enhance the radiation data resolution using elevation maps. Tested on a mountainous area, this method significantly improved radiation estimates, benefiting predictions of forest functions.

How plants regulate their exchange of CO₂ and water with the atmosphere under global warming is critical for their carbon uptake and their cooling influence. We analyze the isotope ratio of atmospheric CO₂ and detect no significant decadal trends in the seasonal cycle amplitude. The data are consistent with the regulation towards leaf CO₂ and intrinsic water use efficiency growing proportionally to atmospheric CO₂, in contrast to recent suggestions of downregulation of CO₂ and water fluxes.

Drainage of boreal peatlands strongly influences soil methane fluxes, with important implications for climatic impacts. Here we simulate methane fluxes in forestry-drained and restored peatlands during the 21st century. We found that restoration turned peatlands into a source of methane, but the magnitude varied regionally. In forests, changes in the water table level influenced methane fluxes, and in general, the sink was weaker under rotational forestry compared to continuous cover forestry.

In the boreal humic waters of a forest lake and bog, the rate of dissolved organic matter photodegradation is 4 times higher than that of biodegradation. However, given the shallow, light-penetrating layer, the biodegradation provides the largest contribution to CO₂ emissions from water surfaces. Trace metals were partially removed (1–10 %) during photodegradation and biodegradation via precipitation of Fe(III) hydroxides after destabilization of organoferric colloids and organic complexes.

This study exposed a natural community to two non-CO₂-equilibrated ocean alkalinity enhancement (OAE) deployments using different minerals. Adding alkalinity in this manner decreases dissolved CO₂, essential for photosynthesis. While photosynthesis was not suppressed, bloom formation was mildly delayed, potentially impacting marine food webs. The study emphasizes the need for further research on OAE without prior equilibration and on its ecological implications.

Despite interest in modeling the biogeochemical uptake and cycling of the trace metal zinc (Zn), measurements of Zn uptake in natural marine phytoplankton communities have not been conducted previously. To fill this gap, we employed a stable isotope uptake rate measurement method to quantify Zn uptake into natural phytoplankton assemblages within the Southern Ocean. Zn demand was high and rapid enough to depress the inventory of Zn available to phytoplankton on seasonal timescales.

We investigated the formation of early Archean (~3.5–3.4 Ga) carbonates in the Pilbara Craton, Western Australia, demonstrating the presence of an oceanic crust, an organo-carbonate, and a microbial carbonate factory. Notably, (a)biotic organic matter and hydrothermal fluids were centrally involved in carbonate precipitation. Since carbonates were widespread in the Archean, they may have constituted major carbon sinks that modulated early Earth’s carbon cycle and, hence, climate system.

The distribution of N₂O in fjord-like estuaries is poorly described in the Southern Hemisphere. Our study describes N₂O distribution and its drivers in one such system in Macquarie Harbour, Tasmania. Water samples were collected seasonally in 2022 and 2023. Results show the system removes atmospheric N₂O when river flow is high, whereas the system emits N₂O when the river flow is low. N₂O generated in basins is intercepted by the surface water and exported to the ocean during high river flow.

We present a fully automatic, low-cost soil–plant enclosure system to monitor CO₂ and evapotranspiration fluxes within greenhouse experiments. It operates in two modes: independent, using low-cost sensors, and dependent, where multiple chambers connect to a single gas analyzer via a low-cost multiplexer. This system provides precise, accurate measurements and high temporal resolution, enabling comprehensive monitoring of plant–soil responses to various treatments and conditions.