Permafrost thaw in Arctic watersheds threatens to mobilize hitherto sequestered carbon. We examine the radiocarbon activity (FC) of dissolved organic carbon (DOC) in the northern Mackenzie River basin. From 2003-2017, DOC-FC signatures (1.00 ± 0.04; = 39) tracked atmospheric CO, indicating export of "modern" carbon. This trend was interrupted in June 2018 by the widespread release of aged DOC (0.85 ± 0.16, = 28) measured across three separate catchment areas. Increased nitrate concentrations in June 2018 lead us to attribute this pulse of C-depleted DOC to mobilization of previously frozen soil organic matter. We propose export through lateral perennial thaw zones that occurred at the base of the active layer weakened by preceding warm summer and winter seasons. Although we are not yet able to ascertain the broader significance of this "anomalous" mobilization event, it highlights the potential for rapid and large-scale release of aged carbon from permafrost.
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http://dx.doi.org/10.1029/2020GL088823 | DOI Listing |
Sci Rep
December 2024
Grassland Technique Extension Station of Gansu Province, Lanzhou, 730000, Gansu, China.
Near-natural restoration is acknowledged as an effective strategy for enhancing soil organic carbon (SOC) sequestration in degraded grasslands. However, the alterations in SOC fractions, stability, and relative sequestration capacity after restoration of degraded alpine meadows remain uncertain. In this study, we utilized the degraded alpine meadows on the northeastern edge of the Tibetan Plateau as a research area, with grazing as the control (CK) and restoration of 20 years of banned grazing (BG) and growing season resting grazing (RG).
View Article and Find Full Text PDFEnviron Pollut
December 2024
Key Laboratory of Poyang Lake Watershed Agricultural Resource and Ecology of Ministry of Agriculture and Rural Affairs, College of Land Resource and Environment, Jiangxi Agricultural University, Nanchang 330045, China. Electronic address:
Per- and polyfluoroalkyl substances (PFAS) are widely distributed in paddy soils, and their multi-phase partitioning in soil fractions was proved to be strongly interact with soil microbial community composition and functions. Despite this, soil bacterial and fungal metabolic molecular effects on PFAS water-soil interface migration in waterlogged paddy fields still remain unclear. This study integrated soil untargeted metabolomics with microbial amplicon sequencing to elucidate soil metabolic modulations of 15 PFAS interface release.
View Article and Find Full Text PDFSci Total Environ
December 2024
Institute for Water Quality and Resource Management, TU Wien, Karlsplatz 13/226, 1040 Vienna, Austria.
Fluorescence fingerprinting is a technique to uniquely characterize water samples based on their distinct composition of dissolved organic matter (DOM) measured via 3D fluorescence spectroscopy. It is an effective tool for monitoring the chemical composition of various water systems. This study examines a river affected by several municipal and industrial wastewater treatment plant (WWTP) effluents and aims to source-tracing them via fluorescence fingerprints based on parallel factor analysis (PARAFAC) components.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Material Science, BASF SE, RGA/BM-B007, Carl-Bosch-Str. 38, D-67056 Ludwigshafen, Germany.
The controlled formation and stabilization of nanoparticles is of fundamental relevance for materials science and key to many modern technologies. Common synthetic strategies to arrest growth at small sizes and prevent undesired particle agglomeration often rely on the use of organic additives and require non-aqueous media and/or high temperatures, all of which appear critical with respect to production costs, safety, and sustainability. In the present work, we demonstrate a simple one-pot process in water under ambient conditions that can produce particles of various transition metal carbonates and sulfides with sizes of only a few nanometers embedded in a silica shell, similar to particles derived from more elaborate synthesis routes, like the sol-gel process.
View Article and Find Full Text PDFInt Endod J
December 2024
School of Dentistry, The University of Queensland, Brisbane, Queensland, Australia.
Aim: All commercial chelating gels contain EDTA which reacts chemically with sodium hypochlorite (NaOCl). This research aimed to develop a non-EDTA clodronate gel and to measure physicochemical and functional gel properties of the novel and commercial gels.
Methodology: A 1.
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