Articles | Volume 22, issue 7
https://doi.org/10.5194/bg-22-1745-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-22-1745-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
09 Apr 2025
Research article |
| 09 Apr 2025
| 09 Apr 2025
Solubility characteristics of soil humic substances as a function of pH: mechanisms and biogeochemical perspectives
Xuemei Yang
School of Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing, 100091, China
Jie Zhang
School of Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
School of Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, Tianjin 300072, China
Mohammad Mohinuzzaman
School of Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
Department of Environmental Science and Disaster Management, Noakhali Science and Technology University, Noakhali, Bangladesh
H. Henry Teng
School of Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, Tianjin 300072, China
Nicola Senesi
Dip.to di Scienze del Suolo, della Pianta e degli Alimenti, Università degli Studi di Bari “Aldo Moro”, Via G. Amendola 165/A, 70126 Bari, Italy
Giorgio S. Senesi
CNR – Istituto per la Scienza e Tecnologia dei Plasmi (ISTP) – sede di Bari Via Amendola, 122/D, 70126 Bari, Italy
Jie Yuan
College of Resources and Environment, Xingtai University, Quanbei East Road 88, Qiaodong District, Xingtai City, Hebei Province, China
Yu Liu
School of Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, Tianjin 300072, China
Si-Liang Li
School of Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, Tianjin 300072, China
Xiaodong Li
School of Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, Tianjin 300072, China
Baoli Wang
School of Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, Tianjin 300072, China
Cong-Qiang Liu
CORRESPONDING AUTHOR
School of Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, Tianjin 300072, China
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Zhichao Dong, Subba Rao Devineni, Xiaoli Fu, Zhanjie Xu, Mingyu Li, Pingqing Fu, Cong-Qiang Liu, and Chandra Mouli Pavuluri
EGUsphere, https://doi.org/10.5194/egusphere-2025-899, https://doi.org/10.5194/egusphere-2025-899, 2025
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
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We developed new method to detect and measure organosulfates in PM2.5. By synthesizing organosulfates and combining them with commercial standards, we improved detection accuracy. Testing air samples from Tianjin, China, we found wintertime levels of organosulfates were much higher than in other regions. Our results show how human actions directly impact air quality and provide a tool to track pollution sources. This work helps scientists understand and address harmful aerosols in environments.
Yaxin Liu, Yunting Xiao, Lehui Cui, Qinghao Guo, Yiyang Sun, Pingqing Fu, Cong-Qiang Liu, and Jialei Zhu
EGUsphere, https://doi.org/10.5194/egusphere-2025-763, https://doi.org/10.5194/egusphere-2025-763, 2025
This preprint is open for discussion and under review for Biogeosciences (BG).
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Dust carries iron deposits into the ocean, providing essential nutrients for the growth of marine phytoplankton, influencing their carbon uptake capacity. A model constrained by global datasets on dust iron content, ocean iron solubility, and dissolved iron concentrations was used to assess the contributions of 11 major dust sources to carbon uptake in 8 marine areas, enhancing understanding of the impact of global dust emissions on marine deposition and carbon cycle with decreased uncertainty.
Yu Xu, Tang Liu, Yi-Jia Ma, Qi-Bin Sun, Hong-Wei Xiao, Hao Xiao, Hua-Yun Xiao, and Cong-Qiang Liu
Atmos. Chem. Phys., 24, 10531–10542, https://doi.org/10.5194/acp-24-10531-2024, https://doi.org/10.5194/acp-24-10531-2024, 2024
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This study investigates the characteristics of aminiums and ammonium in PM2.5 on clean and polluted winter days in 11 Chinese cities, highlighting the possibility of the competitive uptake of ammonia versus amines on acidic aerosols or the displacement of aminiums by ammonia under high-ammonia conditions. The overall results deepen the understanding of the spatiotemporal differences in aminium characteristics and formation in China.
Hao Xiao, Qinkai Li, Shiyuan Ding, Wenjing Dai, Gaoyang Cui, and Xiaodong Li
EGUsphere, https://doi.org/10.5194/egusphere-2024-1621, https://doi.org/10.5194/egusphere-2024-1621, 2024
Preprint archived
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This study established a refined isotopic fingerprint of NOx sources in local Tianjin, which included previously uncharacterized sources in China. Results shown that the representative nature and region-specific characteristics of isotopic fingerprints for six categories of NOx sources in Tianjin. A reasonable source-resolved structure of NO3– could obtained by MixSIAR model using the δ15N values of NOx source established in this study, suggest the important of the refined isotopic fingerprint.
Zhichao Dong, Chandra Mouli Pavuluri, Peisen Li, Zhanjie Xu, Junjun Deng, Xueyan Zhao, Xiaomai Zhao, Pingqing Fu, and Cong-Qiang Liu
Atmos. Chem. Phys., 24, 5887–5905, https://doi.org/10.5194/acp-24-5887-2024, https://doi.org/10.5194/acp-24-5887-2024, 2024
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Comprehensive study of optical properties of brown carbon (BrC) in fine aerosols from Tianjin, China, implied that biological emissions are major sources of BrC in summer, whereas fossil fuel combustion and biomass burning emissions are in cold periods. The direct radiation absorption caused by BrC in short wavelengths contributed about 40 % to that caused by BrC in 300–700 nm. Water-insoluble but methanol-soluble BrC contains more protein-like chromophores (PLOM) than that of water-soluble BrC.
Shuai Chen, Jun Zhong, Lishan Ran, Yuanbi Yi, Wanfa Wang, Zelong Yan, Si-liang Li, and Khan M. G. Mostofa
Biogeosciences, 20, 4949–4967, https://doi.org/10.5194/bg-20-4949-2023, https://doi.org/10.5194/bg-20-4949-2023, 2023
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This study found the source of dissolved organic carbon and its optical properties (e.g., aromaticity, humification) are related to human land use and catchment slope in anthropogenically impacted subtropical mountainous rivers. The study highlights that the combination of dual carbon isotopes and optical properties represents a useful tool in tracing the origin of dissolved organic carbon and its in-stream processes.
Zhichao Dong, Chandra Mouli Pavuluri, Zhanjie Xu, Yu Wang, Peisen Li, Pingqing Fu, and Cong-Qiang Liu
Atmos. Chem. Phys., 23, 2119–2143, https://doi.org/10.5194/acp-23-2119-2023, https://doi.org/10.5194/acp-23-2119-2023, 2023
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This study has provided comprehensive baseline data of carbonaceous and inorganic aerosols as well as their isotope ratios in the Tianjin region, North China, found that Tianjin aerosols were derived from coal combustion, biomass burning and photochemical reactions of VOCs, and also implied that the Tianjin aerosols were more aged during long-range atmospheric transport in summer via carbonaceous and isotope data analysis.
Shujun Zhong, Shuang Chen, Junjun Deng, Yanbing Fan, Qiang Zhang, Qiaorong Xie, Yulin Qi, Wei Hu, Libin Wu, Xiaodong Li, Chandra Mouli Pavuluri, Jialei Zhu, Xin Wang, Di Liu, Xiaole Pan, Yele Sun, Zifa Wang, Yisheng Xu, Haijie Tong, Hang Su, Yafang Cheng, Kimitaka Kawamura, and Pingqing Fu
Atmos. Chem. Phys., 23, 2061–2077, https://doi.org/10.5194/acp-23-2061-2023, https://doi.org/10.5194/acp-23-2061-2023, 2023
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This study investigated the role of the secondary organic aerosol (SOA) loading on the molecular composition of wintertime urban aerosols by ultrahigh-resolution mass spectrometry. Results demonstrate that the SOA loading is an important factor associated with the oxidation degree, nitrate group content, and chemodiversity of nitrooxy–organosulfates. Our study also found that the hydrolysis of nitrooxy–organosulfates is a possible pathway for the formation of organosulfates.
Junjun Deng, Hao Ma, Xinfeng Wang, Shujun Zhong, Zhimin Zhang, Jialei Zhu, Yanbing Fan, Wei Hu, Libin Wu, Xiaodong Li, Lujie Ren, Chandra Mouli Pavuluri, Xiaole Pan, Yele Sun, Zifa Wang, Kimitaka Kawamura, and Pingqing Fu
Atmos. Chem. Phys., 22, 6449–6470, https://doi.org/10.5194/acp-22-6449-2022, https://doi.org/10.5194/acp-22-6449-2022, 2022
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Light-absorbing brown carbon (BrC) plays an important role in climate change and atmospheric chemistry. Here we investigated the seasonal and diurnal variations in water-soluble BrC in PM2.5 in the megacity Tianjin in coastal China. Results of the source apportionments from the combination with organic molecular compositions and optical properties of water-soluble BrC reveal a large contribution from primary bioaerosol particles to BrC in the urban atmosphere.
Qiaorong Xie, Sihui Su, Jing Chen, Yuqing Dai, Siyao Yue, Hang Su, Haijie Tong, Wanyu Zhao, Lujie Ren, Yisheng Xu, Dong Cao, Ying Li, Yele Sun, Zifa Wang, Cong-Qiang Liu, Kimitaka Kawamura, Guibin Jiang, Yafang Cheng, and Pingqing Fu
Atmos. Chem. Phys., 21, 11453–11465, https://doi.org/10.5194/acp-21-11453-2021, https://doi.org/10.5194/acp-21-11453-2021, 2021
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This study investigated the role of nighttime chemistry during Chinese New Year's Eve that enhances the formation of nitrooxy organosulfates in the aerosol phase. Results show that anthropogenic precursors, together with biogenic ones, considerably contribute to the formation of low-volatility nitrooxy OSs. Our study provides detailed molecular composition of firework-related aerosols, which gives new insights into the physicochemical properties and potential health effects of urban aerosols.
Jing Yang, Wanyu Zhao, Lianfang Wei, Qiang Zhang, Yue Zhao, Wei Hu, Libin Wu, Xiaodong Li, Chandra Mouli Pavuluri, Xiaole Pan, Yele Sun, Zifa Wang, Cong-Qiang Liu, Kimitaka Kawamura, and Pingqing Fu
Atmos. Chem. Phys., 20, 6841–6860, https://doi.org/10.5194/acp-20-6841-2020, https://doi.org/10.5194/acp-20-6841-2020, 2020
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Our observations provide novel detailed information on the atmospheric abundances and spatial distributions of dicarboxylic acids, oxoacids, and α-dicarbonyls in marine aerosols collected from the South China Sea to the East Indian Ocean. Our results demonstrate that the continental outflow of both biogenic and anthropogenic precursors followed by photochemical aging is one of the main sources and formation processes of marine organic aerosols over the tropical oceanic regions.
Qiaorong Xie, Sihui Su, Shuang Chen, Yisheng Xu, Dong Cao, Jing Chen, Lujie Ren, Siyao Yue, Wanyu Zhao, Yele Sun, Zifa Wang, Haijie Tong, Hang Su, Yafang Cheng, Kimitaka Kawamura, Guibin Jiang, Cong-Qiang Liu, and Pingqing Fu
Atmos. Chem. Phys., 20, 6803–6820, https://doi.org/10.5194/acp-20-6803-2020, https://doi.org/10.5194/acp-20-6803-2020, 2020
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Current knowledge on firework-related organic aerosols is very limited. Here the detailed molecular composition of organics in urban aerosols was characterized using ultrahigh-resolution FT-ICR mass spectrometry. Our findings highlight that firework emission leads to a sharp increase in CHO, CHNO, and CHOS containing high-molecular-weight species, particularly aromatic-like substances, which affect the physicochemical properties such as the light absorption and health effects of urban aerosols.
Yijun Liu, Jie Yuan, Fu-Jun Yue, Si-Liang Li, Baoli Wang, Mohammad Mohinuzzaman, Xuemei Yang, Nicola Senesi, Xinyu Lao, Longlong Li, Cong-Qiang Liu, Rob M. Ellam, and Khan M. G. Mostofa
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-145, https://doi.org/10.5194/bg-2020-145, 2020
Manuscript not accepted for further review
Yanbing Fan, Cong-Qiang Liu, Linjie Li, Lujie Ren, Hong Ren, Zhimin Zhang, Qinkai Li, Shuang Wang, Wei Hu, Junjun Deng, Libin Wu, Shujun Zhong, Yue Zhao, Chandra Mouli Pavuluri, Xiaodong Li, Xiaole Pan, Yele Sun, Zifa Wang, Kimitaka Kawamura, Zongbo Shi, and Pingqing Fu
Atmos. Chem. Phys., 20, 117–137, https://doi.org/10.5194/acp-20-117-2020, https://doi.org/10.5194/acp-20-117-2020, 2020
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This study provides useful knowledge on the abundance, sources, and formation processes of organic aerosols in the coastal megacity of Tianjin, North China, based on the investigation of the molecular composition, diurnal variation, and winter/summer differences under the influence of land/sea breezes and the Asian summer monsoon.
Chongli Di, Tiejun Wang, Xiaohua Yang, and Siliang Li
Hydrol. Earth Syst. Sci., 22, 5069–5079, https://doi.org/10.5194/hess-22-5069-2018, https://doi.org/10.5194/hess-22-5069-2018, 2018
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The original Grassberger–Procaccia algorithm for complex analysis was modified by incorporating the normal-based K-means clustering technique and the RANSAC algorithm. The calculation accuracy of the proposed method was shown to outperform traditional algorithms. The proposed algorithm was used to diagnose climate system complexity in the Hai He basin. The spatial patterns of the complexity of precipitation and air temperature reflected the influence of the dominant climate system.
Khan M. G. Mostofa, Cong-Qiang Liu, WeiDong Zhai, Marco Minella, Davide Vione, Kunshan Gao, Daisuke Minakata, Takemitsu Arakaki, Takahito Yoshioka, Kazuhide Hayakawa, Eiichi Konohira, Eiichiro Tanoue, Anirban Akhand, Abhra Chanda, Baoli Wang, and Hiroshi Sakugawa
Biogeosciences, 13, 1767–1786, https://doi.org/10.5194/bg-13-1767-2016, https://doi.org/10.5194/bg-13-1767-2016, 2016
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Exploring microscale heterogeneity as a driver of biogeochemical transformations and gas transport in peat
Dissolved organic matter fosters core mercury-methylating microbiomes for methylmercury production in paddy soils
A microbially driven and depth-explicit soil organic carbon model constrained by carbon isotopes to reduce parameter equifinality
Earth observation reveals reduced winter wheat growth and the importance of plant available water during drought
Plutonium concentrations link soil organic matter decline to wind erosion in ploughed soils of South Africa
A synthesis of Sphagnum litterbag experiments: initial leaching losses bias decomposition rate estimates
Effect of straw retention and mineral fertilization on P speciation and P-transformation microorganisms in water- extractable colloids of a Vertisol
A new approach to continuous monitoring of carbon use efficiency and biosynthesis in soil microbes from measurement of CO2 and O2
Validating laboratory insights into the drivers of soil rewetting respiration pulses with field measurements
Diverse organic carbon dynamics captured by radiocarbon analysis of distinct compound classes in a grassland soil
Effects of basalt, concrete fines, and steel slag on maize growth and heavy metal accumulation in an enhanced weathering experiment
The effects of land use on soil carbon stocks in the UK
Technical note: A validated correction method to quantify organic and inorganic carbon in soils using Rock-Eval® thermal analysis
Depth Effects of Long-term Organic Residue Application on Soil Organic Carbon Stocks in Central Kenya
Distinct changes in carbon, nitrogen, and phosphorus cycling in the litter layer across two contrasting forest-tundra ecotones
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Factors controlling spatiotemporal variability of soil carbon accumulation and stock estimates in a tidal salt marsh
Moisture and temperature effects on the radiocarbon signature of respired carbon dioxide to assess stability of soil carbon in the Tibetan Plateau
Non-mycorrhizal root-associated fungi increase soil C stocks and stability via diverse mechanisms
Drought counteracts soil warming more strongly in the subsoil than in the topsoil according to a vertical microbial SOC model
Nine years of warming and nitrogen addition in the Tibetan grassland promoted loss of soil organic carbon but did not alter the bulk change in chemical structure
Soil priming effects and involved microbial community along salt gradients
Adjustments to the Rock-Eval® thermal analysis for soil organic and inorganic carbon quantification
Ecosystem-specific patterns and drivers of global reactive iron mineral-associated organic carbon
Dark septate endophytic fungi associated with pioneer grass inhabiting volcanic deposits and their functions in promoting plant growth
Global patterns and drivers of phosphorus fractions in natural soils
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How well does ramped thermal oxidation quantify the age distribution of soil carbon? Assessing thermal stability of physically and chemically fractionated soil organic matter
Differential temperature sensitivity of intracellular metabolic processes and extracellular soil enzyme activities
Mapping soil organic carbon fractions for Australia, their stocks, and uncertainty
Technical note: The recovery rate of free particulate organic matter from soil samples is strongly affected by the method of density fractionation
Deforestation for agriculture leads to soil warming and enhanced litter decomposition in subarctic soils
Temperature sensitivity of soil organic carbon respiration along a forested elevation gradient in the Rwenzori Mountains, Uganda
The influence of elevated CO2 and soil depth on rhizosphere activity and nutrient availability in a mature Eucalyptus woodland
The paradox of assessing greenhouse gases from soils for nature-based solutions
Management-induced changes in soil organic carbon on global croplands
Pore network modeling as a new tool for determining gas diffusivity in peat
Temperature sensitivity of dark CO2 fixation in temperate forest soils
Effects of precipitation seasonality, irrigation, vegetation cycle and soil type on enhanced weathering – modeling of cropland case studies across four sites
Stable isotope profiles of soil organic carbon in forested and grassland landscapes in the Lake Alaotra basin (Madagascar): insights in past vegetation changes
Reviews and syntheses: The promise of big diverse soil data, moving current practices towards future potential
Dynamics of rare earth elements and associated major and trace elements during Douglas-fir (Pseudotsuga menziesii) and European beech (Fagus sylvatica L.) litter degradation
To what extent can soil moisture and soil Cu contamination stresses affect nitrous species emissions? Estimation through calibration of a nitrification–denitrification model
Carbon, nitrogen, and phosphorus stoichiometry of organic matter in Swedish forest soils and its relationship with climate, tree species, and soil texture
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Lukas Kohl, Petri Kiuru, Marjo Palviainen, Maarit Raivonen, Markku Koskinen, Mari Pihlatie, and Annamari Laurén
Biogeosciences, 22, 1711–1727, https://doi.org/10.5194/bg-22-1711-2025, https://doi.org/10.5194/bg-22-1711-2025, 2025
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We present an assay to illuminate heterogeneity in biogeochemical transformations within peat samples. For this, we injected isotope-labeled acetate into peat cores and monitored the release of label-derived gases, which we compared to microtomography images. The fraction of label converted to CO2 and the rapidness of this conversion were linked to injection depth and air-filled porosity.
Qiang Pu, Bo Meng, Jen-How Huang, Kun Zhang, Jiang Liu, Yurong Liu, Mahmoud A. Abdelhafiz, and Xinbin Feng
Biogeosciences, 22, 1543–1556, https://doi.org/10.5194/bg-22-1543-2025, https://doi.org/10.5194/bg-22-1543-2025, 2025
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This study examines the effect of dissolved organic matter (DOM) on microbial mercury (Hg) methylation in paddy soils. It uncovers that DOM regulates Hg methylation mainly through altering core Hg-methylating microbiome composition and boosting the growth of core Hg-methylating microorganisms. The study highlights that in the regulation of methylmercury formation in paddy soils, more attention should be paid to changes in DOM concentration and composition.
Marijn Van de Broek, Gerard Govers, Marion Schrumpf, and Johan Six
Biogeosciences, 22, 1427–1446, https://doi.org/10.5194/bg-22-1427-2025, https://doi.org/10.5194/bg-22-1427-2025, 2025
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Soil organic carbon models are used to predict how soils affect the concentration of CO2 in the atmosphere. We show that equifinality – the phenomenon that different parameter values lead to correct overall model outputs, albeit with a different model behaviour – is an important source of model uncertainty. Our results imply that adding more complexity to soil organic carbon models is unlikely to lead to better predictions as long as more data to constrain model parameters are not available.
Hanna Sjulgård, Lukas Valentin Graf, Tino Colombi, Juliane Hirte, Thomas Keller, and Helge Aasen
Biogeosciences, 22, 1341–1354, https://doi.org/10.5194/bg-22-1341-2025, https://doi.org/10.5194/bg-22-1341-2025, 2025
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Our study showed that stress-related crop response to changing environmental conditions can be detected by monitoring crops using satellite images at the landscape level. This could be useful for farmers to identify when stresses occur. Our results also suggest that satellite imagery can be used to discover soil impacts on crop development at farm fields. The inclusion of soil properties in satellite image analyses could further improve the accuracy of the prediction of drought stress on crops.
Joel Mohren, Hendrik Wiesel, Wulf Amelung, L. Keith Fifield, Alexandra Sandhage-Hofmann, Erik Strub, Steven A. Binnie, Stefan Heinze, Elmarie Kotze, Chris Du Preez, Stephen G. Tims, and Tibor J. Dunai
Biogeosciences, 22, 1077–1094, https://doi.org/10.5194/bg-22-1077-2025, https://doi.org/10.5194/bg-22-1077-2025, 2025
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We measured concentrations of nuclear fallout in soil samples taken from arable land in South Africa. We find that during the second half of the 20th century, the data strongly correlate with the organic matter content of the soils. The finding implies that wind erosion strongly influenced the loss of organic matter in the soils we investigated. Furthermore, the exponential decline of fallout concentrations and organic matter content over time peaks shortly after native grassland is ploughed.
Henning Teickner, Edzer Pebesma, and Klaus-Holger Knorr
Biogeosciences, 22, 417–433, https://doi.org/10.5194/bg-22-417-2025, https://doi.org/10.5194/bg-22-417-2025, 2025
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Decomposition rates for Sphagnum mosses, the main peat-forming plants in northern peatlands, are often derived from litterbag experiments. Here, we estimate initial leaching losses from available Sphagnum litterbag experiments and analyze how decomposition rates are biased when initial leaching losses are ignored. Our analyses indicate that initial leaching losses range between 3 to 18 mass-% and that this may result in overestimated mass losses when extrapolated to several decades.
Shanshan Bai, Yifei Ge, Dongtan Yao, Yifan Wang, Jinfang Tan, Shuai Zhang, Yutao Peng, and Xiaoqian Jiang
Biogeosciences, 22, 135–151, https://doi.org/10.5194/bg-22-135-2025, https://doi.org/10.5194/bg-22-135-2025, 2025
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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.
Kyle E. Smart, Daniel O. Breecker, Christopher B. Blackwood, and Timothy M. Gallagher
Biogeosciences, 22, 87–101, https://doi.org/10.5194/bg-22-87-2025, https://doi.org/10.5194/bg-22-87-2025, 2025
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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.
Xiankun Li, Marleen Pallandt, Dilip Naidu, Johannes Rousk, Gustaf Hugelius, and Stefano Manzoni
EGUsphere, https://doi.org/10.5194/egusphere-2024-3324, https://doi.org/10.5194/egusphere-2024-3324, 2024
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While laboratory studies have identified many drivers and their effects on the carbon emission pulse after rewetting of dry soils, a validation with field data is still missing. Here, we show that the carbon emission pulse in the laboratory and in the field increases with soil organic carbon and temperature, but their trends with pre-rewetting dryness and moisture increment at rewetting differ. We conclude that the laboratory findings can be partially validated.
Katherine E. Grant, Marisa N. Repasch, Kari M. Finstad, Julia D. Kerr, Maxwell Marple, Christopher J. Larson, Taylor A. B. Broek, Jennifer Pett-Ridge, and Karis J. McFarlane
Biogeosciences, 21, 4395–4411, https://doi.org/10.5194/bg-21-4395-2024, https://doi.org/10.5194/bg-21-4395-2024, 2024
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Soils store organic carbon composed of multiple compounds from plants and microbes for different lengths of time. To understand how soils store these different carbon types, we measure the time each carbon fraction is in a grassland soil profile. Our results show that the length of time each individual soil fraction is in our soil changes. Our approach allows a detailed look at the different components in soils. This study can help improve our understanding of soil dynamics.
Jet Rijnders, Arthur Vienne, and Sara Vicca
EGUsphere, https://doi.org/10.5194/egusphere-2024-3022, https://doi.org/10.5194/egusphere-2024-3022, 2024
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A mesocosm experiment was set-up to investigate how maize responds to basalt, concrete fines and steel slags application, using a dose-response approach. Biomass increased with basalt application, but did not change with concrete fines or steel slags, except for increased tassel biomass. Mg, Ca and Si generally increased in the crops, while heavy metal concentrations remained unaffected or even decreased in the plants. Overall, crops were positively affected by application of silicate materials.
Peter Levy, Laura Bentley, Peter Danks, Bridget Emmett, Angus Garbutt, Stephen Heming, Peter Henrys, Aidan Keith, Inma Lebron, Niall McNamara, Richard Pywell, John Redhead, David Robinson, and Alexander Wickenden
Biogeosciences, 21, 4301–4315, https://doi.org/10.5194/bg-21-4301-2024, https://doi.org/10.5194/bg-21-4301-2024, 2024
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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.
Marija Stojanova, Pierre Arbelet, François Baudin, Nicolas Bouton, Giovanni Caria, Lorenza Pacini, Nicolas Proix, Edouard Quibel, Achille Thin, and Pierre Barré
Biogeosciences, 21, 4229–4237, https://doi.org/10.5194/bg-21-4229-2024, https://doi.org/10.5194/bg-21-4229-2024, 2024
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Because of its importance for climate regulation and soil health, many studies focus on carbon dynamics in soils. However, quantifying organic and inorganic carbon remains an issue in carbonated soils. In this technical note, we propose a validated correction method to quantify organic and inorganic carbon in soils using Rock-Eval® thermal analysis. With this correction, the Rock-Eval® method has the potential to become the standard method for quantifying carbon in carbonate soils.
Claude Raoul Müller, Johan Six, Daniel Mugendi Njiru, Bernard Vanlauwe, and Marijn Van de Broek
EGUsphere, https://doi.org/10.5194/egusphere-2024-2796, https://doi.org/10.5194/egusphere-2024-2796, 2024
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We studied how different organic and inorganic nutrient inputs affect soil organic carbon (SOC) down to 70 cm in Kenya. After 19 years, all organic treatments increased SOC stocks as compared to the control, but mineral nitrogen had no significant effect. Manure was the organic treatment that significantly increased SOC the deepest as its effect could be observed down to 60 cm. Manure was the best strategy to limit SOC loss in croplands and maintain soil quality after deforestation.
Frank Hagedorn, Joesphine Imboden, Pavel Moiseev, Decai Gao, Emmanuel Frossard, Daniel Christen, Konstantin Gavazov, and Jasmin Fetzer
EGUsphere, https://doi.org/10.5194/egusphere-2024-2622, https://doi.org/10.5194/egusphere-2024-2622, 2024
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At treeline, plant species change abruptly from low stature plants in tundra to trees in forests. Our study documents that from tundra towards forest, the litter layer gets strongly enriched in nutrients. We show that these litter quality changes alter nutrient processing by soil microbes and increase the nutrient release during decomposition in forest than in tundra. The associated improvement of nutrient availability in the forest potentially stimulates tree growth and treeline shifts.
Armando Molina, Veerle Vanacker, Oliver Chadwick, Santiago Zhiminaicela, Marife Corre, and Edzo Veldkamp
Biogeosciences, 21, 3075–3091, https://doi.org/10.5194/bg-21-3075-2024, https://doi.org/10.5194/bg-21-3075-2024, 2024
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The tropical Andes contains unique landscapes where forest patches are surrounded by tussock grasses and cushion-forming plants. The aboveground vegetation composition informs us about belowground nutrient availability: patterns in plant-available nutrients resulted from strong biocycling of cations and removal of soil nutrients by plant uptake or leaching. Future changes in vegetation distribution will affect soil water and solute fluxes and the aquatic ecology of Andean rivers and lakes.
Sahiti Bulusu, Cristina Prieto García, Helen E. Dahlke, and Elad Levintal
Biogeosciences, 21, 3007–3013, https://doi.org/10.5194/bg-21-3007-2024, https://doi.org/10.5194/bg-21-3007-2024, 2024
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Do-it-yourself hardware is a new way to improve measurement resolution. We present a low-cost, automated system for field measurements of low nitrate concentrations in soil porewater and open water bodies. All data hardware components cost USD 1100, which is much cheaper than other available commercial solutions. We provide the complete building guide to reduce technical barriers, which we hope will allow easier reproducibility and set up new soil and environmental monitoring applications.
Violeta Mendoza-Martinez, Scott L. Collins, and Jennie R. McLaren
Biogeosciences, 21, 2655–2667, https://doi.org/10.5194/bg-21-2655-2024, https://doi.org/10.5194/bg-21-2655-2024, 2024
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We examine the impacts of multi-decadal nitrogen additions on a dryland ecosystem N budget, including the soil, microbial, and plant N pools. After 26 years, there appears to be little impact on the soil microbial or plant community and only minimal increases in N pools within the soil. While perhaps encouraging from a conservation standpoint, we calculate that greater than 95 % of the nitrogen added to the system is not retained and is instead either lost deeper in the soil or emitted as gas.
Sean Fettrow, Andrew Wozniak, Holly A. Michael, and Angelia L. Seyfferth
Biogeosciences, 21, 2367–2384, https://doi.org/10.5194/bg-21-2367-2024, https://doi.org/10.5194/bg-21-2367-2024, 2024
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Salt marshes play a big role in global carbon (C) storage, and C stock estimates are used to predict future changes. However, spatial and temporal gradients in C burial rates over 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 beside several porewater biogeochemical variables and discussed the controls on variability in soil C in salt marsh ecosystems.
Andrés Tangarife-Escobar, Georg Guggenberger, Xiaojuan Feng, Guohua Dai, Carolina Urbina-Malo, Mina Azizi-Rad, and Carlos A. Sierra
Biogeosciences, 21, 1277–1299, https://doi.org/10.5194/bg-21-1277-2024, https://doi.org/10.5194/bg-21-1277-2024, 2024
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Soil organic matter stability depends on future temperature and precipitation scenarios. We used radiocarbon (14C) data and model predictions to understand how the transit time of carbon varies under environmental change in grasslands and peatlands. Soil moisture affected the Δ14C of peatlands, while temperature did not have any influence. Our models show the correspondence between Δ14C and transit time and could allow understanding future interactions between terrestrial and atmospheric carbon
Emiko K. Stuart, Laura Castañeda-Gómez, Wolfram Buss, Jeff R. Powell, and Yolima Carrillo
Biogeosciences, 21, 1037–1059, https://doi.org/10.5194/bg-21-1037-2024, https://doi.org/10.5194/bg-21-1037-2024, 2024
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We inoculated wheat plants with various types of fungi whose impacts on soil carbon are poorly understood. After several months of growth, we examined both their impacts on soil carbon and the underlying mechanisms using multiple methods. Overall the fungi benefitted the storage of carbon in soil, mainly by improving the stability of pre-existing carbon, but several pathways were involved. This study demonstrates their importance for soil carbon storage and, therefore, climate change mitigation.
Marleen Pallandt, Marion Schrumpf, Holger Lange, Markus Reichstein, Lin Yu, and Bernhard Ahrens
EGUsphere, https://doi.org/10.5194/egusphere-2024-186, https://doi.org/10.5194/egusphere-2024-186, 2024
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As soils get warmer due to climate change, SOC decomposes faster because of higher microbial activity, but only with sufficient soil moisture. We modelled how microbes decompose plant litter and microbial residues at different soil depths. We found that deep soil layers are more sensitive than topsoils. SOC is lost from the soil with warming, but this can be mitigated or worsened depending on the type of litter and its sensitivity to temperature. Droughts can reduce warming-induced SOC losses.
Huimin Sun, Michael W. I. Schmidt, Jintao Li, Jinquan Li, Xiang Liu, Nicholas O. E. Ofiti, Shurong Zhou, and Ming Nie
Biogeosciences, 21, 575–589, https://doi.org/10.5194/bg-21-575-2024, https://doi.org/10.5194/bg-21-575-2024, 2024
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A soil organic carbon (SOC) molecular structure suggested that the easily decomposable and stabilized SOC is similarly affected after 9-year warming and N treatments despite large changes in SOC stocks. Given the long residence time of some SOC, the similar loss of all measurable chemical forms of SOC under global change treatments could have important climate consequences.
Haoli Zhang, Doudou Chang, Zhifeng Zhu, Chunmei Meng, and Kaiyong Wang
Biogeosciences, 21, 1–11, https://doi.org/10.5194/bg-21-1-2024, https://doi.org/10.5194/bg-21-1-2024, 2024
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Soil salinity mediates microorganisms and soil processes like soil organic carbon (SOC) cycling. We observed that negative priming effects at the early stages might be due to the preferential utilization of cottonseed meal. The positive priming that followed decreased with the increase in salinity.
Joséphine Hazera, David Sebag, Isabelle Kowalewski, Eric Verrecchia, Herman Ravelojaona, and Tiphaine Chevallier
Biogeosciences, 20, 5229–5242, https://doi.org/10.5194/bg-20-5229-2023, https://doi.org/10.5194/bg-20-5229-2023, 2023
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This study adapts the Rock-Eval® protocol to quantify soil organic carbon (SOC) and soil inorganic carbon (SIC) on a non-pretreated soil aliquot. The standard protocol properly estimates SOC contents once the TOC parameter is corrected. However, it cannot complete the thermal breakdown of SIC amounts > 4 mg, leading to an underestimation of high SIC contents by the MinC parameter, even after correcting for this. Thus, the final oxidation isotherm is extended to 7 min to quantify any SIC amount.
Bo Zhao, Amin Dou, Zhiwei Zhang, Zhenyu Chen, Wenbo Sun, Yanli Feng, Xiaojuan Wang, and Qiang Wang
Biogeosciences, 20, 4761–4774, https://doi.org/10.5194/bg-20-4761-2023, https://doi.org/10.5194/bg-20-4761-2023, 2023
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This study provided a comprehensive analysis of the spatial variability and determinants of Fe-bound organic carbon (Fe-OC) among terrestrial, wetland, and marine ecosystems and its governing factors globally. We illustrated that reactive Fe was not only an important sequestration mechanism for OC in terrestrial ecosystems but also an effective “rusty sink” of OC preservation in wetland and marine ecosystems, i.e., a key factor for long-term OC storage in global ecosystems.
Han Sun, Tomoyasu Nishizawa, Hiroyuki Ohta, and Kazuhiko Narisawa
Biogeosciences, 20, 4737–4749, https://doi.org/10.5194/bg-20-4737-2023, https://doi.org/10.5194/bg-20-4737-2023, 2023
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In this research, we assessed the diversity and function of the dark septate endophytic (DSE) fungi community associated with Miscanthus condensatus root in volcanic ecosystems. Both metabarcoding and isolation were adopted in this study. We further validated effects on plant growth by inoculation of some core DSE isolates. This study helps improve our understanding of the role of Miscanthus condensatus-associated DSE fungi during the restoration of post-volcanic ecosystems.
Xianjin He, Laurent Augusto, Daniel S. Goll, Bruno Ringeval, Ying-Ping Wang, Julian Helfenstein, Yuanyuan Huang, and Enqing Hou
Biogeosciences, 20, 4147–4163, https://doi.org/10.5194/bg-20-4147-2023, https://doi.org/10.5194/bg-20-4147-2023, 2023
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We identified total soil P concentration as the most important predictor of all soil P pool concentrations, except for primary mineral P concentration, which is primarily controlled by soil pH and only secondarily by total soil P concentration. We predicted soil P pools’ distributions in natural systems, which can inform assessments of the role of natural P availability for ecosystem productivity, climate change mitigation, and the functioning of the Earth system.
Imane Slimani, Xia Zhu-Barker, Patricia Lazicki, and William Horwath
Biogeosciences, 20, 3873–3894, https://doi.org/10.5194/bg-20-3873-2023, https://doi.org/10.5194/bg-20-3873-2023, 2023
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There is a strong link between nitrogen availability and iron minerals in soils. These minerals have multiple outcomes for nitrogen availability depending on soil conditions and properties. For example, iron can limit microbial degradation of nitrogen in aerated soils but has opposing outcomes in non-aerated soils. This paper focuses on the multiple ways iron can affect nitrogen bioavailability in soils.
Shane W. Stoner, Marion Schrumpf, Alison Hoyt, Carlos A. Sierra, Sebastian Doetterl, Valier Galy, and Susan Trumbore
Biogeosciences, 20, 3151–3163, https://doi.org/10.5194/bg-20-3151-2023, https://doi.org/10.5194/bg-20-3151-2023, 2023
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Soils store more carbon (C) than any other terrestrial C reservoir, but the processes that control how much C stays in soil, and for how long, are very complex. Here, we used a recent method that involves heating soil in the lab to measure the range of C ages in soil. We found that most C in soil is decades to centuries old, while some stays for much shorter times (days to months), and some is thousands of years old. Such detail helps us to estimate how soil C may react to changing climate.
Adetunji Alex Adekanmbi, Laurence Dale, Liz Shaw, and Tom Sizmur
Biogeosciences, 20, 2207–2219, https://doi.org/10.5194/bg-20-2207-2023, https://doi.org/10.5194/bg-20-2207-2023, 2023
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The decomposition of soil organic matter and flux of carbon dioxide are expected to increase as temperatures rise. However, soil organic matter decomposition is a two-step process whereby large molecules are first broken down outside microbial cells and then respired within microbial cells. We show here that these two steps are not equally sensitive to increases in soil temperature and that global warming may cause a shift in the rate-limiting step from outside to inside the microbial cell.
Mercedes Román Dobarco, Alexandre M. J-C. Wadoux, Brendan Malone, Budiman Minasny, Alex B. McBratney, and Ross Searle
Biogeosciences, 20, 1559–1586, https://doi.org/10.5194/bg-20-1559-2023, https://doi.org/10.5194/bg-20-1559-2023, 2023
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Soil organic carbon (SOC) is of a heterogeneous nature and varies in chemistry, stabilisation mechanisms, and persistence in soil. In this study we mapped the stocks of SOC fractions with different characteristics and turnover rates (presumably PyOC >= MAOC > POC) across Australia, combining spectroscopy and digital soil mapping. The SOC stocks (0–30 cm) were estimated as 13 Pg MAOC, 2 Pg POC, and 5 Pg PyOC.
Frederick Büks
Biogeosciences, 20, 1529–1535, https://doi.org/10.5194/bg-20-1529-2023, https://doi.org/10.5194/bg-20-1529-2023, 2023
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Ultrasonication with density fractionation of soils is a commonly used method to separate soil organic matter pools, which is, e.g., important to calculate carbon turnover in landscapes. It is shown that the approach that merges soil and dense solution without mixing has a low recovery rate and causes co-extraction of parts of the retained labile pool along with the intermediate pool. An alternative method with high recovery rates and no cross-contamination was recommended.
Tino Peplau, Christopher Poeplau, Edward Gregorich, and Julia Schroeder
Biogeosciences, 20, 1063–1074, https://doi.org/10.5194/bg-20-1063-2023, https://doi.org/10.5194/bg-20-1063-2023, 2023
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We buried tea bags and temperature loggers in a paired-plot design in soils under forest and agricultural land and retrieved them after 2 years to quantify the effect of land-use change on soil temperature and litter decomposition in subarctic agricultural systems. We could show that agricultural soils were on average 2 °C warmer than forests and that litter decomposition was enhanced. The results imply that deforestation amplifies effects of climate change on soil organic matter dynamics.
Joseph Okello, Marijn Bauters, Hans Verbeeck, Samuel Bodé, John Kasenene, Astrid Françoys, Till Engelhardt, Klaus Butterbach-Bahl, Ralf Kiese, and Pascal Boeckx
Biogeosciences, 20, 719–735, https://doi.org/10.5194/bg-20-719-2023, https://doi.org/10.5194/bg-20-719-2023, 2023
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The increase in global and regional temperatures has the potential to drive accelerated soil organic carbon losses in tropical forests. We simulated climate warming by translocating intact soil cores from higher to lower elevations. The results revealed increasing temperature sensitivity and decreasing losses of soil organic carbon with increasing elevation. Our results suggest that climate warming may trigger enhanced losses of soil organic carbon from tropical montane forests.
Johanna Pihlblad, Louise C. Andresen, Catriona A. Macdonald, David S. Ellsworth, and Yolima Carrillo
Biogeosciences, 20, 505–521, https://doi.org/10.5194/bg-20-505-2023, https://doi.org/10.5194/bg-20-505-2023, 2023
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Elevated CO2 in the atmosphere increases forest biomass productivity when growth is not limited by soil nutrients. This study explores how mature trees stimulate soil availability of nitrogen and phosphorus with free-air carbon dioxide enrichment after 5 years of fumigation. We found that both nutrient availability and processes feeding available pools increased in the rhizosphere, and phosphorus increased at depth. This appears to not be by decomposition but by faster recycling of nutrients.
Rodrigo Vargas and Van Huong Le
Biogeosciences, 20, 15–26, https://doi.org/10.5194/bg-20-15-2023, https://doi.org/10.5194/bg-20-15-2023, 2023
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Quantifying the role of soils in nature-based solutions requires accurate estimates of soil greenhouse gas (GHG) fluxes. We suggest that multiple GHG fluxes should not be simultaneously measured at a few fixed time intervals, but an optimized sampling approach can reduce bias and uncertainty. Our results have implications for assessing GHG fluxes from soils and a better understanding of the role of soils in nature-based solutions.
Kristine Karstens, Benjamin Leon Bodirsky, Jan Philipp Dietrich, Marta Dondini, Jens Heinke, Matthias Kuhnert, Christoph Müller, Susanne Rolinski, Pete Smith, Isabelle Weindl, Hermann Lotze-Campen, and Alexander Popp
Biogeosciences, 19, 5125–5149, https://doi.org/10.5194/bg-19-5125-2022, https://doi.org/10.5194/bg-19-5125-2022, 2022
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Soil organic carbon (SOC) has been depleted by anthropogenic land cover change and agricultural management. While SOC models often simulate detailed biochemical processes, the management decisions are still little investigated at the global scale. We estimate that soils have lost around 26 GtC relative to a counterfactual natural state in 1975. Yet, since 1975, SOC has been increasing again by 4 GtC due to a higher productivity, recycling of crop residues and manure, and no-tillage practices.
Petri Kiuru, Marjo Palviainen, Arianna Marchionne, Tiia Grönholm, Maarit Raivonen, Lukas Kohl, and Annamari Laurén
Biogeosciences, 19, 5041–5058, https://doi.org/10.5194/bg-19-5041-2022, https://doi.org/10.5194/bg-19-5041-2022, 2022
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Peatlands are large carbon stocks. Emissions of carbon dioxide and methane from peatlands may increase due to changes in management and climate. We studied the variation in the gas diffusivity of peat with depth using pore network simulations and laboratory experiments. Gas diffusivity was found to be lower in deeper peat with smaller pores and lower pore connectivity. However, gas diffusivity was not extremely low in wet conditions, which may reflect the distinctive structure of peat.
Rachael Akinyede, Martin Taubert, Marion Schrumpf, Susan Trumbore, and Kirsten Küsel
Biogeosciences, 19, 4011–4028, https://doi.org/10.5194/bg-19-4011-2022, https://doi.org/10.5194/bg-19-4011-2022, 2022
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Soils will likely become warmer in the future, and this can increase the release of carbon dioxide (CO2) into the atmosphere. As microbes can take up soil CO2 and prevent further escape into the atmosphere, this study compares the rate of uptake and release of CO2 at two different temperatures. With warming, the rate of CO2 uptake increases less than the rate of release, indicating that the capacity to modulate soil CO2 release into the atmosphere will decrease under future warming.
Giuseppe Cipolla, Salvatore Calabrese, Amilcare Porporato, and Leonardo V. Noto
Biogeosciences, 19, 3877–3896, https://doi.org/10.5194/bg-19-3877-2022, https://doi.org/10.5194/bg-19-3877-2022, 2022
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Enhanced weathering (EW) is a promising strategy for carbon sequestration. Since models may help to characterize field EW, the present work applies a hydro-biogeochemical model to four case studies characterized by different rainfall seasonality, vegetation and soil type. Rainfall seasonality strongly affects EW dynamics, but low carbon sequestration suggests that an in-depth analysis at the global scale is required to see if EW may be effective to mitigate climate change.
Vao Fenotiana Razanamahandry, Marjolein Dewaele, Gerard Govers, Liesa Brosens, Benjamin Campforts, Liesbet Jacobs, Tantely Razafimbelo, Tovonarivo Rafolisy, and Steven Bouillon
Biogeosciences, 19, 3825–3841, https://doi.org/10.5194/bg-19-3825-2022, https://doi.org/10.5194/bg-19-3825-2022, 2022
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In order to shed light on possible past vegetation shifts in the Central Highlands of Madagascar, we measured stable isotope ratios of organic carbon in soil profiles along both forested and grassland hillslope transects in the Lake Alaotra region. Our results show that the landscape of this region was more forested in the past: soils in the C4-dominated grasslands contained a substantial fraction of C3-derived carbon, increasing with depth.
Katherine E. O. Todd-Brown, Rose Z. Abramoff, Jeffrey Beem-Miller, Hava K. Blair, Stevan Earl, Kristen J. Frederick, Daniel R. Fuka, Mario Guevara Santamaria, Jennifer W. Harden, Katherine Heckman, Lillian J. Heran, James R. Holmquist, Alison M. Hoyt, David H. Klinges, David S. LeBauer, Avni Malhotra, Shelby C. McClelland, Lucas E. Nave, Katherine S. Rocci, Sean M. Schaeffer, Shane Stoner, Natasja van Gestel, Sophie F. von Fromm, and Marisa L. Younger
Biogeosciences, 19, 3505–3522, https://doi.org/10.5194/bg-19-3505-2022, https://doi.org/10.5194/bg-19-3505-2022, 2022
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Research data are becoming increasingly available online with tantalizing possibilities for reanalysis. However harmonizing data from different sources remains challenging. Using the soils community as an example, we walked through the various strategies that researchers currently use to integrate datasets for reanalysis. We find that manual data transcription is still extremely common and that there is a critical need for community-supported informatics tools like vocabularies and ontologies.
Alessandro Montemagno, Christophe Hissler, Victor Bense, Adriaan J. Teuling, Johanna Ziebel, and Laurent Pfister
Biogeosciences, 19, 3111–3129, https://doi.org/10.5194/bg-19-3111-2022, https://doi.org/10.5194/bg-19-3111-2022, 2022
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We investigated the biogeochemical processes that dominate the release and retention of elements (nutrients and potentially toxic elements) during litter degradation. Our results show that toxic elements are retained in the litter, while nutrients are released in solution during the first stages of degradation. This seems linked to the capability of trees to distribute the elements between degradation-resistant and non-degradation-resistant compounds of leaves according to their chemical nature.
Laura Sereni, Bertrand Guenet, Charlotte Blasi, Olivier Crouzet, Jean-Christophe Lata, and Isabelle Lamy
Biogeosciences, 19, 2953–2968, https://doi.org/10.5194/bg-19-2953-2022, https://doi.org/10.5194/bg-19-2953-2022, 2022
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This study focused on the modellisation of two important drivers of soil greenhouse gas emissions: soil contamination and soil moisture change. The aim was to include a Cu function in the soil biogeochemical model DNDC for different soil moisture conditions and then to estimate variation in N2O, NO2 or NOx emissions. Our results show a larger effect of Cu on N2 and N2O emissions than on the other nitrogen species and a higher effect for the soils incubated under constant constant moisture.
Marie Spohn and Johan Stendahl
Biogeosciences, 19, 2171–2186, https://doi.org/10.5194/bg-19-2171-2022, https://doi.org/10.5194/bg-19-2171-2022, 2022
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We explored the ratios of carbon (C), nitrogen (N), and phosphorus (P) of organic matter in Swedish forest soils. The N : P ratio of the organic layer was most strongly related to the mean annual temperature, while the C : N ratios of the organic layer and mineral soil were strongly related to tree species even in the subsoil. The organic P concentration in the mineral soil was strongly affected by soil texture, which diminished the effect of tree species on the C to organic P (C : OP) ratio.
Moritz Mainka, Laura Summerauer, Daniel Wasner, Gina Garland, Marco Griepentrog, Asmeret Asefaw Berhe, and Sebastian Doetterl
Biogeosciences, 19, 1675–1689, https://doi.org/10.5194/bg-19-1675-2022, https://doi.org/10.5194/bg-19-1675-2022, 2022
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The largest share of terrestrial carbon is stored in soils, making them highly relevant as regards global change. Yet, the mechanisms governing soil carbon stabilization are not well understood. The present study contributes to a better understanding of these processes. We show that qualitative changes in soil organic matter (SOM) co-vary with alterations of the soil matrix following soil weathering. Hence, the type of SOM that is stabilized in soils might change as soils develop.
Jasmin Fetzer, Emmanuel Frossard, Klaus Kaiser, and Frank Hagedorn
Biogeosciences, 19, 1527–1546, https://doi.org/10.5194/bg-19-1527-2022, https://doi.org/10.5194/bg-19-1527-2022, 2022
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As leaching is a major pathway of nitrogen and phosphorus loss in forest soils, we investigated several potential drivers in two contrasting beech forests. The composition of leachates, obtained by zero-tension lysimeters, varied by season, and climatic extremes influenced the magnitude of leaching. Effects of nitrogen and phosphorus fertilization varied with soil nutrient status and sorption properties, and leaching from the low-nutrient soil was more sensitive to environmental factors.
Karis J. McFarlane, Heather M. Throckmorton, Jeffrey M. Heikoop, Brent D. Newman, Alexandra L. Hedgpeth, Marisa N. Repasch, Thomas P. Guilderson, and Cathy J. Wilson
Biogeosciences, 19, 1211–1223, https://doi.org/10.5194/bg-19-1211-2022, https://doi.org/10.5194/bg-19-1211-2022, 2022
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Planetary warming is increasing seasonal thaw of permafrost, making this extensive old carbon stock vulnerable. In northern Alaska, we found more and older dissolved organic carbon in small drainages later in summer as more permafrost was exposed by deepening thaw. Younger and older carbon did not differ in chemical indicators related to biological lability suggesting this carbon can cycle through aquatic systems and contribute to greenhouse gas emissions as warming increases permafrost thaw.
Pengzhi Zhao, Daniel Joseph Fallu, Sara Cucchiaro, Paolo Tarolli, Clive Waddington, David Cockcroft, Lisa Snape, Andreas Lang, Sebastian Doetterl, Antony G. Brown, and Kristof Van Oost
Biogeosciences, 18, 6301–6312, https://doi.org/10.5194/bg-18-6301-2021, https://doi.org/10.5194/bg-18-6301-2021, 2021
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We investigate the factors controlling the soil organic carbon (SOC) stability and temperature sensitivity of abandoned prehistoric agricultural terrace soils. Results suggest that the burial of former topsoil due to terracing provided an SOC stabilization mechanism. Both the soil C : N ratio and SOC mineral protection regulate soil SOC temperature sensitivity. However, which mechanism predominantly controls SOC temperature sensitivity depends on the age of the buried terrace soils.
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Short summary
The solubility characteristics of soil humic acids (HAs), fulvic acids (FAs), and protein-like substances (PLSs) at varying pH levels remain unclear. The key findings include the following: HA solubility increases with increasing pH and decreases with decreasing pH; HApH6 and HApH1 contribute to 39.1–49.2% and 3.1–24.1% of dissolved organic carbon, respectively; and HApH2, FA, and PLSs are highly soluble at acidic pHs and are transported by ambient water. These issues are crucial for sustainable soil management.
The solubility characteristics of soil humic acids (HAs), fulvic acids (FAs), and protein-like...
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