Oxygen availability regulates the quality of soil dissolved organic matter by mediating microbial metabolism and iron oxidation

Global Change Biology, Journal Year: 2022, Volume and Issue: 28(24), P. 7410 - 7427

Published: Sept. 23, 2022

Dissolved organic matter (DOM) plays a vital role in biogeochemical processes and determining the responses of soil (SOM) to global change. Although quantity DOM has been inventoried across diverse spatio-temporal scales, underlying mechanisms accounting for variability dynamics remain unclear especially upland ecosystems. Here, gradient SOM storage 12 croplands northeast China was used understand links between dynamics, microbial metabolism, abiotic conditions. We assessed composition, biodegradability, key biodegradable components DOM. In addition, mineral-associated (MAOM) enzyme activities, oxygen availability, texture, iron (Fe), Fe-bound matter, nutrient concentrations were quantified clarify drivers quality (composition biodegradability). The proportion increased exponentially with decreasing initial concentration due larger fractions depolymerized that rich small-molecular phenols proteinaceous components. Unexpectedly, composition decoupled from or MAOM, but significantly related enzymatic properties. These results indicate metabolism exhibited dominant generation. As declined, availability regulated enhanced its biodegradability mainly through mediating Fe oxidation. oxygen-induced oxidation Fe(II) Fe(III) removed complex compounds large molecular weight. Moreover, stimulated oxidase-catalyzed depolymerization aromatic substances, promoted production protein-like lower C/N acquisition ratio. changes temperature moisture will have impacts on regulating highlights importance integrating supply redox status improve model predictions carbon under climate

Language: Английский

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Response of dissolved organic matter (DOM) and microbial community to submerged macrophytes restoration in lakes: A review

Environmental Research, Journal Year: 2023, Volume and Issue: 231, P. 116185 - 116185

Published: May 17, 2023

Language: Английский

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Dissolved organic carbon concentration and biodegradability across the global rivers: A meta-analysis

The Science of The Total Environment, Journal Year: 2021, Volume and Issue: 818, P. 151828 - 151828

Published: Nov. 20, 2021

Language: Английский

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Tundra wildfire triggers sustained lateral nutrient loss in Alaskan Arctic

Global Change Biology, Journal Year: 2021, Volume and Issue: 27(7), P. 1408 - 1430

Published: Jan. 4, 2021

Abstract Climate change is creating widespread ecosystem disturbance across the permafrost zone, including a rapid increase in extent and severity of tundra wildfire. The expansion this previously rare has unknown consequences for lateral nutrient flux from terrestrial to aquatic environments. Lateral loss nutrients could reduce carbon uptake slow recovery already nutrient‐limited ecosystems. To investigate effects wildfire on export, we analyzed water chemistry around 10‐year‐old Anaktuvuk River fire scar northern Alaska. We collected samples 21 burned unburned watersheds during snowmelt, at peak growing season, after plant senescence 2017 2018. After decade recovery, aboveground biomass had recovered watersheds, but overall nitrogen remained ~20% lower, active layer ~10% deeper. Despite lower organic matter stocks, dissolved were substantially elevated with higher flow‐weighted concentrations (25% higher), (59% phosphorus (65% sulfur (47% higher). Geochemical proxies indicated greater interaction mineral soils surface subsidence, optical analysis isotopes suggested that recent growth, not soil, was main source watersheds. Burned similar δ 15 N‐NO 3 − , indicating exported preburn origin (i.e., recently fixed). 2‐ 10‐fold than rates background fixation atmospheric deposition estimated area. These findings indicate Arctic can destabilize nitrogen, phosphorus, stored via leaching. This plant‐mediated exacerbate limitation or serve as an important release mechanism succession.

Language: Английский

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A globally relevant stock of soil nitrogen in the Yedoma permafrost domain

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Oct. 14, 2022

Abstract Nitrogen regulates multiple aspects of the permafrost climate feedback, including plant growth, organic matter decomposition, and production potent greenhouse gas nitrous oxide. Despite its importance, current estimates nitrogen are highly uncertain. Here, we compiled a dataset >2000 samples to quantify stocks in Yedoma domain, region with organic-rich that contains ~25% all carbon. We estimate domain 41.2 gigatons down ~20 metre for deepest unit, which increases previous entire zone by ~46%. Approximately 90% this (37 gigatons) is stored therefore currently immobile frozen. show amount, ¾ >3 depth, but if partially mobilised thaw, large pool could have continental-scale consequences soil aquatic biogeochemistry global-scale feedback.

Language: Английский

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Meta-Analysis of Optical Surrogates for the Characterization of Dissolved Organic Matter

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(17), P. 7380 - 7392

Published: April 19, 2024

Optical surrogates, derived from absorbance and fluorescence spectra, are widely used to infer dissolved organic matter (DOM) composition (molecular weight, aromaticity) genesis (autochthonous vs allochthonous). Despite the broad adoption of optical several limitations exist, such as context- sample-specific factors. These create uncertainty about how compositional interpretations based on surrogates generalized across contexts, specifically if there is duplicative or contradictory information in those interpretations. To explore these limitations, we performed a meta-analysis for DOM diverse sources, both natural systems after water treatment processes (

Language: Английский

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Stream Dissolved Organic Matter in Permafrost Regions Shows Surprising Compositional Similarities but Negative Priming and Nutrient Effects

Global Biogeochemical Cycles, Journal Year: 2020, Volume and Issue: 35(1)

Published: Nov. 18, 2020

Abstract Permafrost degradation is delivering bioavailable dissolved organic matter (DOM) and inorganic nutrients to surface water networks. While these permafrost subsidies represent a small portion of total fluvial DOM nutrient fluxes, they could influence food webs net ecosystem carbon balance via priming or effects that destabilize background DOM. We investigated how addition biolabile (acetate) (nitrogen phosphorus) affected decomposition with 28‐day incubations. incubated late‐summer stream from 23 locations nested in seven northern high‐altitude regions Asia, Europe, North America. loss ranged 3% 52%, showing variety longitudinal patterns within optical properties varied widely, but showed compositional similarity based on Fourier transform ion cyclotron resonance mass spectrometry (FT‐ICR MS) analysis. Addition acetate decreased bulk mineralization (i.e., negative priming), more biodegradable neutral positive stable Unexpectedly, triggered breakdown colored (CDOM), median decreases 1.6% the control 22% amended treatment. Additionally, uptake added was strongly limited by availability across sites. These findings suggest released degrading may decrease alter stoichiometry light conditions receiving waterbodies. conclude are coupled aquatic ecosystems quantifying two‐way interactions between environmental resolve conflicting observations about drivers zone waterways.

Language: Английский

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Groundwater Plays an Important Role in Controlling Riverine Dissolved Organic Matter in a Cold Alpine Catchment, the Qinghai–Tibet Plateau

Water Resources Research, Journal Year: 2023, Volume and Issue: 59(2)

Published: Jan. 30, 2023

Abstract In cold alpine areas, the hydrological control on dissolved organic matter (DOM) export in relation to permafrost distribution remains uncertain a catchment scale. To address this, seasonal variations DOM chemical features of groundwater and stream water were examined from 2013 2019 representative northeastern Qinghai–Tibet Plateau, which is covered by both (at elevations higher than 3,500 m a.s.l.) seasonally frozen areas. The results show that highest carbon (DOC) concentration occurred during thawing period (April–May), while DOC flux thawed (June–early October). area, freeze–thaw process significantly influenced flow paths DOM. During period, with shallow path through soil layer, recharged suprapermafrost was characterized high aromaticity concentrations. deepening mineral layer dilution overland flow, resulted low concentrations lower water. When flowed area into porous aquifers also affected dynamics. at outlet, received discharge aquifer, showed peak concentration, proportion protein‐like DOM, contribution season annual when compared flowing out area. Our work highlights role thick, aquifer regulating export. suggest may exhibit stronger positive feedback climate warming Arctic

Language: Английский

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Subsea permafrost organic carbon stocks are large and of dominantly low reactivity

Scientific Reports, Journal Year: 2023, Volume and Issue: 13(1)

Published: June 9, 2023

Abstract Subsea permafrost carbon pools below the Arctic shelf seas are a major unknown in global cycle. We combine numerical model of sedimentation and evolution with simplified turnover to estimate accumulation microbial decomposition organic matter on pan-Arctic over past four glacial cycles. find that is globally important long-term sink storing 2822 (1518–4982) Pg OC, double amount stored lowland permafrost. Although currently thawing, prior aging limit rates less than 48 Tg OC/yr (25–85) constraining emissions due thaw suggesting large pool largely insensitive thaw. identify an urgent need reduce uncertainty cold saline subaquatic environments. Large methane more likely derive from older deeper sources thawing

Language: Английский

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Terrestrial Dissolved Organic Matter Mobilized From Eroding Permafrost Controls Microbial Community Composition and Growth in Arctic Coastal Zones

Frontiers in Earth Science, Journal Year: 2021, Volume and Issue: 9

Published: March 24, 2021

Climate warming is accelerating erosion along permafrost-dominated Arctic coasts. This results in the additional supply of organic matter (OM) and nutrients into coastal zone. In this study we investigate impact on marine microbial community composition growth rates Beaufort Sea. Dissolved (DOM) derived from three representative glacial deposit types (fluvial, lacustrine, moraine) Yukon plain, Canada, were used as substrate to cultivate bacteria using a chemostat setup. Our show that DOM (inferred UV-Visible spectroscopy) biodegradability DOC concentration, bacterial production respiration) significantly differ between types. fluvial moraine clear terrestrial characteristics with low aromaticity ( S r : 0.63 ± 0.02 SUVA 254 1.65 0.06 L mg C −1 m & 0.68 0.01 1.17 , respectively) compared lacustrine soil type 0.71 2.15 0.05 ). The difference leads development different communities. Whereas Alphaproteobacteria dominate (67 87% relative abundance, respectively), Gammaproteobacteria most abundant class for (88% abundance). Bacterial efficiency (BGE) 66% type, while 13 28% types, respectively. communities therefore strongly their net effect utilization depending eroded landscape type. high BGE value moraine-derived probably caused by larger proportion labile colorless DOM. These indicate controls activities waters. suggests biogeochemical changes zone will depend character adjacent which determine speed extent mineralization thereby carbon channeling food web. We conclude microbes respond input released differently influence microbes.

Language: Английский

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