Deepening roots can enhance carbonate weathering by amplifying CO<sub>2</sub>-rich recharge

Biogeosciences, Journal Year: 2021, Volume and Issue: 18(1), P. 55 - 75

Published: Jan. 5, 2021

Abstract. Carbonate weathering is essential in regulating atmospheric CO2 and carbon cycle at the century timescale. Plant roots accelerate by elevating soil via respiration. It however remains poorly understood how much rooting characteristics (e.g., depth density distribution) modify flow paths weathering. We address this knowledge gap using field data from reactive transport numerical experiments Konza Prairie Biological Station (Konza), Kansas (USA), a site where woody encroachment into grasslands surmised to deepen roots. Results indicate that deepening can enhance two ways. First, control thermodynamic limits of carbonate dissolution transports vertical downward deeper carbonate-rich zone. The base-case model reveal concentrations Ca dissolved inorganic (DIC) are regulated pCO2 driven seasonal This relationship be encapsulated equations derived work describing dependence DIC on temperature CO2. explain spring water multiple carbonate-dominated catchments. Second, show rates recharge (or fluxes) zone export reaction products equilibrium. explored potential effects partitioning 40 % infiltrated woodlands compared 5 grasslands. Soil suggest relatively similar distribution over depth, which leads only 1 ∼ 12 difference if was kept same between land covers. In contrast, 17 200 as infiltration increased 3.7 × 10−2 m/a. Weathering these cases more than an order magnitude higher case without all, underscoring role general. Numerical also fronts propagated > 2 times after 300 years rate 0.37 These differences ultimately caused contact CO2-charged with deep subsurface. Within limitation modeling exercises, prompt hypothesis (1) promoting CO2–carbonate subsurface (2) hydrological impacts influential those modulating rates. call for colocated characterizations roots, structure, levels, well their linkage chemistry. measurements will illuminate feedback mechanisms cover changes, chemical weathering, global cycle, climate.

Language: Английский

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Vertical Connectivity Regulates Water Transit Time and Chemical Weathering at the Hillslope Scale

Water Resources Research, Journal Year: 2021, Volume and Issue: 57(8)

Published: July 13, 2021

Abstract How does hillslope structure (e.g., shape and permeability variation) regulate its hydro‐geochemical functioning (flow paths, solute export, chemical weathering)? Numerical reactive transport experiments particle tracking were used to answer this question. Results underscore the first‐order control of variations (with depth) on vertical connectivity (VC), defined as fraction water flowing into streams from below soil zone. Where decreases sharply VC is low, >95% flows through top 6 m subsurface, barely interacting with rock at depth. High also elongates mean transit times (MTTs) weathering rates. however less an influence under arid climates where long drive equilibrium. The results lead three working hypotheses that can be further tested. H1 : depth MTTs stream more strongly than shapes; shapes instead younger . H2 arising high depths enhances by promoting deeper penetration water‐rock interactions; weakens larger hillslopes longer H3 regulates contrasts between shallow deep waters (C ratio ) export patterns encapsulated in power law slope b concentration‐discharge (CQ) relationships Higher leads similar versus chemistry ∼1) chemostatic CQ Although supporting data already exist, these tested carefully designed, co‐located modeling measurements soil, rock, waters. Broadly, importance subsurface indicate it essential regulating earth surface hydrogeochemical response changing climate human activities.

Language: Английский

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From Soils to Streams: Connecting Terrestrial Carbon Transformation, Chemical Weathering, and Solute Export Across Hydrological Regimes

Water Resources Research, Journal Year: 2022, Volume and Issue: 58(7)

Published: June 13, 2022

Abstract Soil biota generates carbon that exports vertically to the atmosphere (CO 2 ) and transports laterally streams rivers (dissolved organic inorganic carbon, DOC DIC). These processes, together with chemical weathering, vary flow paths across hydrological regimes; yet an integrated understanding of these interactive processes is still lacking. Here we ask: How what extent do subsurface transformation, solute export differ structure regimes? We address this question using a hillslope reactive transport model calibrated soil CO water chemistry data from Fitch, temperate forest at ecotone boundary Eastern mid‐continent grasslands in Kansas, USA. Model results show droughts (discharge 0.08 mm/day) promoted deeper paths, longer transit time, carbonate precipitation, mineralization (OC) into (IC) (∼98% OC). Of IC produced, ∼86% was emitted upward as gas ∼14% exported DIC stream. Storms (8.0 led dissolution but reduced OC (∼88% OC) production (∼12% lateral fluxes (∼53% produced IC). Differences shallow‐versus‐deep permeability contrasts smaller difference (<10%) than discharge‐induced differences were most pronounced under wet conditions. High (low vertical connectivity) enhanced fluxes. generally delineate hillslopes active producers transporters dry conditions, transporter

Language: Английский

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Magnetic MXene based metal organic frameworks composites: Synthesis, characterization and application

Journal of environmental chemical engineering, Journal Year: 2022, Volume and Issue: 10(3), P. 108037 - 108037

Published: June 1, 2022

Language: Английский

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Catchment concentration–discharge relationships across temporal scales: A review

Wiley Interdisciplinary Reviews Water, Journal Year: 2023, Volume and Issue: 11(2)

Published: Dec. 7, 2023

Abstract Processes that drive variability in catchment solute sourcing, transformation, and transport can be investigated using concentration–discharge (C–Q) relationships. These relationships reflect in‐stream processes operating across nested temporal scales, incorporating both short long‐term patterns. Scientists therefore leverage catchment‐scale C–Q datasets to identify distinguish among the underlying meteorological, biological, geological export patterns from catchments influence shape of their respective We have synthesized current knowledge regarding geological, meteorological on for various types diel decadal time scales. cross‐scale linkages tools researchers use explore these interactions Finally, we gaps our understanding dynamics as reflections processes. also lay foundation developing an integrated approach investigate relationships, reflecting biogeochemical effects environmental change water quality. This article is categorized under: Science Water > Hydrological Quality Environmental Change

Language: Английский

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