Microbial response to deliquescence of nitrate-rich soils in the hyperarid Atacama Desert Biogeosciences DOI 10.5194/bg-21-5305-2024 29 November 2024 We studied unique nitrate-rich soils in the hyperarid Atacama Desert that form brines at night under high relative humidity. Despite providing water for microorganisms, these soils exhibit extremely low microbial activity, indicating that the high nitrate levels inhibit microbial life. On the other hand, enriched organic matter indicates their potential preservation. This research helps to understand the limits of life in extreme environments and aids in the search for signs of life on Mars. Read more
Microbial strong organic-ligand production is tightly coupled to iron in hydrothermal plumes Biogeosciences DOI 10.5194/bg-21-5233-2024 29 November 2024 Hydrothermally derived iron can be transported kilometers away from deep-sea vents, representing a significant flux of vital micronutrients to the ocean. However, the mechanisms that support the stabilization of dissolved iron remain elusive. Using electrochemical, spectrometry, and genomic methods, we demonstrated that strong ligands exert an important control on iron in plumes, and high-affinity iron-binding siderophores were identified in several hydrothermal plume samples for the first time Read more
Representation of the terrestrial carbon cycle in CMIP6 Biogeosciences DOI 10.5194/bg-21-5321-2024 28 November 2024 This study investigates present-day carbon cycle variables in CMIP5 and CMIP6 simulations. Overall, CMIP6 models perform better but also show many remaining biases. A significant improvement in the simulation of photosynthesis in models with a nitrogen cycle is found, with only small differences between emission- and concentration-based simulations. Thus, we recommend using emission-driven simulations in CMIP7 by default and including the nitrogen cycle in all future carbon cycle models. Read more
X-BASE: the first terrestrial carbon and water flux products from an extended data-driven scaling framework, FLUXCOM-X Biogeosciences DOI 10.5194/bg-21-5079-2024 25 November 2024 The movement of water, carbon, and energy from the Earth’s surface to the atmosphere, or flux, is an important process to understand because it impacts our lives. Here, we outline a method called FLUXCOM-X to estimate global water and CO2 fluxes based on direct measurements from sites around the world. We go on to demonstrate how these new estimates of net CO2 uptake/loss, gross CO2 uptake, total water evaporation, and transpiration from plants compare to previous and independent estimates. BASE: the first terrestrial carbon and water flux products from an extended data-driven scaling framework, FLUXCOM-X">Read more
How to measure the efficiency of bioenergy crops compared to forestation Biogeosciences DOI 10.5194/bg-21-5005-2024 15 November 2024 Using a state-of-the-art land model, we find that bioenergy plants can store carbon more efficiently than forests over long periods in the soil, in geological reservoirs, or by substituting fossil-fuel-based energy. Planting forests is more suitable for reaching climate targets by 2050. The carbon removal potential depends also on local environmental conditions. These considerations have important implications for climate policy, spatial planning, nature conservation, and agriculture. Read more
Seafloor sediment characterization improves estimates of organic carbon standing stocks: an example from the Eastern Shore Islands, Nova Scotia, Canada Biogeosciences DOI 10.5194/bg-21-4569-2024 25 October 2024 Quantifying how much organic carbon is stored in seafloor sediments is key to assessing how human activities can accelerate the process of carbon storage at the seabed, an important consideration for climate change. This study uses seafloor sediment maps to model organic carbon content. Carbon estimates were 12 times higher when assuming the absence of detailed sediment maps, demonstrating that high-resolution seafloor mapping is critically important for improved estimates of organic carbon. Read more
The effects of land use on soil carbon stocks in the UK Biogeosciences DOI 10.5194/bg-21-4301-2024 4 October 2024 We collated a large data set (15 790 soil cores) on soil carbon stock in different land uses. Soil carbon stocks were highest in woodlands and lowest in croplands. The variability in the effects was large. This has important implications for agri-environment schemes seeking to sequester carbon in the soil by altering land use because the effect of a given intervention is very hard to verify. Read more
CO2 emissions of drained coastal peatlands in the Netherlands and potential emission reduction by water infiltration systems Biogeosciences DOI 10.5194/bg-21-4099-2024 20 September 2024 Drained peatlands cause high CO2 emissions. We assessed the effectiveness of subsurface water infiltration systems (WISs) in reducing CO2 emissions related to increases in water table depth (WTD) on 12 sites for up to 4 years. Results show WISs markedly reduced emissions by 2.1 t CO2-C ha-1 yr-1. The relationship between the amount of carbon above the WTD and CO2 emission was stronger than the relationship between WTD and emission. Long-term monitoring is crucial for accurate emission estimates. Read more
How is particulate organic carbon transported through the river-fed submarine Congo Canyon to the deep sea? Biogeosciences DOI 10.5194/bg-21-4251-2024 6 September 2024 The land-to-ocean flux of particulate organic carbon (POC) is difficult to measure, inhibiting accurate modeling of the global carbon cycle. Here, we quantify the POC flux between one of the largest rivers on Earth (Congo) and the ocean. POC in the form of vegetation and soil is transported by episodic submarine avalanches in a 1000 km long canyon at up to 5 km water depth. The POC flux induced by avalanches is at least 3 times greater than that induced by the background flow related to tides. Read more
Linking geomorphological processes and wildlife microhabitat selection: nesting birds select refuges generated by permafrost degradation in the Arctic Biogeosciences DOI 10.5194/bg-21-3401-2024 26 July 2024 In the Arctic tundra, climate change is transforming the landscape, and this may impact wildlife. We focus on three nesting bird species and the islets they select as refuges from their main predator, the Arctic fox. A geomorphological process, ice-wedge polygon degradation, was found to play a key role in creating these refuges. This process is likely to affect predator–prey dynamics in the Arctic tundra, highlighting the connections between nature’s physical and ecological systems. Read more