Soils are losing increasing amounts of carbon annually to freshwaters as dissolved organic matter (DOM), which, if degraded, can offset their carbon sink capacity. However, the processes underlying DOM degradation across environments are poorly understood. Here we show DOM changes similarly along soil-aquatic gradients irrespective of environmental differences. Using ultrahigh-resolution mass spectrometry, we track DOM along soil depths and hillslope positions in forest catchments and relate its composition to soil microbiomes and physico-chemical conditions. Along depths and hillslopes, we find carbohydrate-like and unsaturated hydrocarbon-like compounds increase in abundance-weighted mass, and the expression of genes essential for degrading plant-derived carbohydrates explains >50% of the variation in abundance of these compounds. These results suggest that microbes transform plant-derived compounds, leaving DOM to become increasingly dominated by the same (i.e., universal), difficult-to-degrade compounds as degradation proceeds. By synthesising data from the land-to-ocean continuum, we suggest these processes generalise across ecosystems and spatiotemporal scales. Such general degradation patterns can help predict DOM composition and reactivity along environmental gradients to inform management of soil-to-stream carbon losses.
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http://dx.doi.org/10.1038/s41467-023-44431-4 | DOI Listing |
Mar Environ Res
December 2024
Key Laboratory of Coastal Biology and Biological Resource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China. Electronic address:
Macroalgae widely distribute in intertidal zones, one of blue carbon organisms. However, the regulatory mechanisms of tide on the carbon sequestration of macroalgae are still unclear. This study explored the effects of desiccation-rewetting cycles induced by tide on dissolved organic carbon (DOC) release from Ulva pertusa, which is prevalent from high to low tidal zones.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Department of Chemistry, College of Science and Engineering, Western Washington University, 516 High Street, Bellingham, WA, 98229, USA.
Fluorescent lifetimes of dissolved organic matter (DOM) and associated physicochemical parameters were measured over 14 months in an estuary in Southern California, USA. Measurements were made on 77 samples from sites near the inlet, mid-estuary, and outlet to maximize the range of physicochemical variables. Time-resolved fluorescence data were well fit to a triexponential model with an intermediate lifetime component (τ: 1 to 5 ns), a long lifetime component (τ: 2 to 15 ns), and a short lifetime component (τ: < 1 ns).
View Article and Find Full Text PDFWater Res
December 2024
The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou 324000, China.
Drinking water flavor, a critical water quality metric, exhibits substantial regional variations across China, influenced by local geology and chemistry. Despite growing consumer concerns about water flavor, a spatial assessment of the determinants of water flavor in China has been notably lacking. This study bridges this gap by conducting a spatially comprehensive analysis of 78 tap water samples throughout China.
View Article and Find Full Text PDFWater Res
December 2024
State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China. Electronic address:
Since elevated amounts of chlorine disinfectant were discharged into surface water, more attention should be paid to the reactions between dissolved organic matter (DOM) and chlorine under sunlight. However, disinfection byproducts (DBPs) formed from DOM by solar photolysis of chlorine, and changes of cytotoxicity during this process remain unclear. In this study, it was found that solar photolysis of chlorine significantly promoted the formation of aliphatic chlorinated DBPs and aromatic chlorinated DBPs (including chlorobenzoquinone) by 44.
View Article and Find Full Text PDFNanoscale
January 2025
Department of Materials Science and Engineering, Chair for Surface Science and Corrosion (WW4-LKO), Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstraße 7, 91058 Erlangen, Germany.
The photocatalytic degradation of unwanted organic species has been investigated for decades using modified and non-modified titania nanostructures. In the present study, we investigate the co-catalytic effect of single atoms (SAs) of Pt and Pt nanoparticles on titania substrates on the degradation of the two typical photodegradation model pollutants: Acid Orange 7 (AO7) and Rhodamine B (RhB). For this, we use highly defined sputter deposited anatase layers and load them with Pt SAs at different loading densities or alternatively with Pt nanoparticles.
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