Recent  

How will the future ocean sequester carbon? We find that for an ocean perpetually warmer with slower circulation, biological productivity declines despite warming-stimulated growth because of lower nutrient supply from depth. This throttles the biological carbon pump, which still sequesters more carbon because it takes longer to return to the surface. The deep ocean is isolated from the surface allowing more carbon from the atmosphere to pass through the ocean without contributing to biology.

Recent studies described the precipitation of carbonates as a result of alkalinity enhancement in seawater, which could adversely affect the carbon sequestation potential of ocean alkalinity enhancement (OAE) approaches. By conducting experiments in natural seawater, this study described uniform patterns during the triggered runaway carbonate precipitation, which allow for the prediction of safe and efficient local application levels of OAE scenarios.

The tropical Andes contains unique landscapes where forest patches are surrounded by tussock grasses and cushion-forming plants. We showed that patterns in plant available nutrients were not mimicking total rock-derived nutrient’ distribution nor exchangeable nutrient pool but resulted from strong biocycling of cations. Vegetation regulates soil biogeochemistry with impacts on nutrient availability in Andean rivers and lakes.

ML models are gaining popularity in biogeosciences. They are applied as gapfilling methods and used to upscale carbon fluxes to larger areas based on local measurements. In this study, we use Explainable ML methods to elucidate performance of machine learning models for carbon dioxide fluxes in boreal forest. We show that statistically equal models treat input variables differently. Explainable ML can help scientists to make informed solutions when applying ML models in their research.

Drained peatlands emit 3 % of the global greenhouse gas emission. Paludiculture is a way to reduce CO₂ emissions while at the same time generating an income for landowners. The side effect is the potentially high methane emission. We found very high methane emission for broadleaf cattail, compared to narrowleaf cattail and water fern. The rewetting was, however, effective to stop CO₂ emission for all species. The highest potential to reduce greenhouse gas emission had narrowleaf cattail.

In this research, we developed a novel method using citizen science data as alternative training data for computer vision models to map plant species in Unoccupied Aerial Vehicles (UAVs) images. We use citizen science plant photographs to train models and apply them to UAV images. We tested our approach on UAV images of a test site with ten different tree species, yielding accurate results. This research shows the potential of citizen science data to advance our ability to monitor plant species.

We use a collection of measurements that captures the physiological sensitivity of organisms to temperature and oxygen, and a model to investigate how natural climate variations and climate warming will impact the ability of marine heterotrophic marine organisms to support habitat in the future. We find that warming and the related loss of marine dissolved oxygen over the next several decades will reduce the volume of ocean habitat, and increasing vulnerability to temperature-oxygen extremes.

Salt marshes play a large role in global C storage, and C stock estimates are used to predict future changes. However, spatial and temporal gradients in C burial rates across the landscape exist due to variations in water inundation, dominant plant species and stage of growth, and tidal action. We quantified soil C concentrations in soil cores across time and space alongside several porewater biogeochemical variables and discussed the controls on variability in soil C in salt marsh ecosystems.

Distribution of phosphomonoesterase (PME) and phosphodiesterase (PDE) activities over the epipelagic zone are described in the eastern Mediterranean Sea, in winter and spring. The type of concentration kinetics obtained for PDE (saturation at 50 µM, high Km, high turnovertimes) compared to those of PME (saturation at 1 µM, low Km, low turnovertimes) are discussed in regard to possible inequal distribution of PDE and PME among organic material size continuum, and accessibility to phosphodiesters.

Carbon monoxide (CO) is considered an important indirect greenhouse gas. Soils can emit as well as take up CO but, until now, uncertainty remains which process dominates in tropical rain forests. We present the first soil CO flux measurements from a tropical rain forest. Based on our observations, we report that tropical rain forest soils are a net source of CO. In addition, we show that valley streams and inundated areas are likely additional hot spots of CO in the ecosystem.

Terrestrial biosphere models can either prescribe the geographical distribution of biomes or simulate them dynamically, capturing climate change-driven biome shifts. We isolate and examine the differences between these different land cover implementations. We find that the simulated terrestrial carbon sink at the end of the 21st century is twice as large in simulations with dynamic land cover than in simulations with prescribed land cover due to important range shifts in the Arctic and Amazon.

Greenhouse gases are produced and consumed via a number of pathways. Quantifying these pathways helps reduce the climate and environmental footprint of anthropogenic activities. The contribution of different pathways can be estimated from the isotopic composition, which acts as a "fingerprint" for these pathways. Interpreting this data is challenging. We have developed the TimeFRAME model to simplify interpretation, and estimate the contribution of different pathways and their uncertainty.

A diverse suite of 'fossils' associated with the ~1.5 Ga Volyn (Ukraine) kerite was published recently. We show that at least some of them represent modern contamination including plant hairs, pollen, and likely later fungal growth. Comparable diversity is shown to exist in modern museum dust, this calling into question whether any part of the Volyn biota is of biological origin while emphasising the need for scrupulous care in collecting, analysing, and identifying Precambrian microfossils.

Water stored in weathered bedrock is rarely incorporated into vegetation and Earth system models, despite increasing recognition of its importance. Here, we add a weathered bedrock component to a widely used vegetation model. Using a case study of two sites in California and model runs across the United States, we show that more accurately representing subsurface water storage and hydrology increases summer plant water use so that it better matches patterns in distributed data products.

Our study delves into the vital role of subalpine forest in the Qinghai-Tibet Plateau as carbon sinks in the context of climate change. Utilizing advanced eddy covariance systems, we uncover their significant carbon sequestration potential, observing distinct seasonal patterns influenced by temperature, humidity, and radiation. Notably, these forest exhibit robust carbon absorption, with potential implications for global carbon balance.

We investigated the origins of nitrous oxide, a potent greenhouse gas, in low oxygen ocean regions. Our findings shed light on the microbial processes behind nitrous oxide production, including “hybrid” nitrous oxide generation by ammonia-oxidizing archaea, one of the most abundant organisms in the ocean. We also observed a strong link between nitrous oxide production and oxygen levels. These results set up potential feedbacks between oxygen depletion and greenhouse gas cycling in the oceans.

Due to climate change, it is projected that extreme rainfall events, bringing terrestrial matter into coastal seas, will occur more frequently in the Mediterranean region. To test the effects of runoffs of terrestrial matter on plankton communities from Mediterranean coastal waters, an in situ mesocosm experiment was conducted. The simulated runoff affected key processes mediated by plankton, such as primary production and respiration, suggesting major consequences of such events.

Ash particles from wildfires are rich in phosphorus (P), a crucial nutrient that constitutes a limiting factor in 43 % of the world's land ecosystems. We hypothesized that wildfire ash could directly contribute to plant nutrition. We found that fire ash application boosts the growth of plants, but the only way plants can uptake P from fire ash is through the foliar uptake pathway, and not through the roots. The fertilization impact of fire ash was maintained also under elevated levels of CO₂.

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 MteqCO2 fire emission, twice the global estimate. Fires contributed to 1.97 % of the country's annual carbon footprint, reducing forest carbon sink by 30 % this year.

Climate change is anticipated to influence the biological pump by altering phytoplankton nutrient distribution. In our research, we collected measurements of particulate matter concentrations during two oceanographic field studies. We observed systematic variations in organic matter concentrations and ratios across the Atlantic Ocean. From statistical modeling, we determined that these variations are associated with differences in the availability of essential nutrients for phytoplankton growth.

We aimed to improve the quality of regional Greenland Sea primary production estimates. Seventy two versions of primary production model setups were tested against field data. Best performing models had local biomass and light absorption profiles. Thus by using local parametrizations for these parameters we can improve Arctic primary production model performance. Annual Greenland Sea basin estimates are larger than previously reported.

The diatom-bound nitrogen isotope proxy is used to study how efficiently diatoms in the Southern Ocean help to remove CO₂ from the atmosphere, but may be biased by different diatom species. We examine a specific type of diatom, Chaetoceros resting spores (CRS), commonly preserved in Southern Ocean sediments. We find that CRS record surprisingly low δ¹⁵N_DB values compared to other diatoms, yet changes in their relative abundance over time does not significantly bias previously published records.

Rate of changes based on compositional data are ambiguous as they may rise irrespective of the underlying trajectory of ecosystems. We emphasise the importance of characterizing both the direction and the rate of palaeoecological changes in terms of key features of ecosystems rather than solely on community composition. Past accelerations of community transformation may document the potential of ecosystems to rapidly recover important ecological attributes and functions.

Soil carbon is the largest store of carbon on the land surface of Earth and is known to be particularly sensitive to climate change. Understanding this future response is vital to successfully meet Paris agreement targets, which rely heavily on carbon uptake by the land surface. In this study, the individual responses of soil carbon are quantified and compared amongst CMIP6 Earth system models used within the most recent IPCC report, and the role of soils within the land response is highlighted.

Plant functional traits have been considered as reflecting the adaptations to environmental variations, indirectly affecting ecosystem productivity. How soil acidification affects above- and belowground biomass via altering leaf and root traits remains poorly understood. We found divergent trait responses driven by soil environmental conditions in two dominate species, leading to a decrease in aboveground biomass while an increase in belowground biomass.

We analyzed benthic foraminifera, nitrogen isotopes and lipids in a sediment core from the Gulf of Oman to investigate how the oxygen minimum zone (OMZ) and the bottom water (BW) oxygenation react to climatic changes since 43 ka BP. The OMZ and BW deoxygenation were strong during the Holocene but the OMZ was well ventilated during the LGM period. We found an unstable mode of oscillating oxygenation states from moderately oxygenated in cold stadials to deoxygenated in warm interstadials in MIS3.

We measured nutrients and dissolved organic matter for one year in a eutrophic tropical estuary to understand their sources and cycling. Our data show that the dissolved organic matter originates partly from land and partly from microbial processes in the water. Internal recycling is likely important for maintaining high nutrient concentrations, and we found that there is often excess nitrogen over silicon and phosphorus. Our data help to explain how eutrophication persists in this system.

This research highlights Spirillina vivipara's calcification strategy, highlighting variability in foraminiferal test formation. By examining its rapid growth and high calcification rate, we explain ecological strategies correlating with its broad coastal distribution. These insights amplify our understanding of foraminiferal ecology and underscore their impact on marine carbon cycling and paleoclimate studies, advocating for a species-specific approach in future research.