Dataset Information

Temporal, Spatial, and Temperature Controls on Organic Carbon Mineralization and Methanogenesis in Arctic High-Centered Polygon Soils.

ABSTRACT: Warming temperatures in continuous permafrost zones of the Arctic will alter both hydrological and geochemical soil conditions, which are strongly linked with heterotrophic microbial carbon (C) cycling. Heterogeneous permafrost landscapes are often dominated by polygonal features formed by expanding ice wedges: water accumulates in low centered polygons (LCPs), and water drains outward to surrounding troughs in high centered polygons (HCPs). These geospatial differences in hydrology cause gradients in biogeochemistry, soil C storage potential, and thermal properties. Presently, data quantifying carbon dioxide (CO₂) and methane (CH₄) release from HCP soils are needed to support modeling and evaluation of warming-induced CO₂ and CH₄ fluxes from tundra soils. This study quantifies the distribution of microbial CO₂ and CH₄ release in HCPs over a range of temperatures and draws comparisons to previous LCP studies. Arctic tundra soils were initially characterized for geochemical and hydraulic properties. Laboratory incubations at -2, +4, and +8°C were used to quantify temporal trends in CO₂ and CH₄ production from homogenized active layer organic and mineral soils in HCP centers and troughs, and methanogen abundance was estimated from mcrA gene measurements. Results showed that soil water availability, organic C, and redox conditions influence temporal dynamics and magnitude of gas production from HCP active layer soils during warming. At early incubation times (2-9 days), higher CO₂ emissions were observed from HCP trough soils than from HCP center soils, but increased CO₂ production occurred in center soils at later times (>20 days). HCP center soils did not support methanogenesis, but CH₄-producing trough soils did indicate methanogen presence. Consistent with previous LCP studies, HCP organic soils showed increased CO₂ and CH₄ production with elevated water content, but HCP trough mineral soils produced more CH₄ than LCP mineral soils. HCP mineral soils also released substantial CO₂ but did not show a strong trend in CO₂ and CH₄ release with water content. Knowledge of temporal and spatial variability in microbial C mineralization rates of Arctic soils in response to warming are key to constraining uncertainties in predictive climate models.

SUBMITTER: Roy Chowdhury T

PROVIDER: S-EPMC7829362 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

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Temporal, Spatial, and Temperature Controls on Organic Carbon Mineralization and Methanogenesis in Arctic High-Centered Polygon Soils.

Roy Chowdhury Taniya T Berns Erin C EC Moon Ji-Won JW Gu Baohua B Liang Liyuan L Wullschleger Stan D SD Graham David E DE

Frontiers in microbiology 20210111

Warming temperatures in continuous permafrost zones of the Arctic will alter both hydrological and geochemical soil conditions, which are strongly linked with heterotrophic microbial carbon (C) cycling. Heterogeneous permafrost landscapes are often dominated by polygonal features formed by expanding ice wedges: water accumulates in low centered polygons (LCPs), and water drains outward to surrounding troughs in high centered polygons (HCPs). These geospatial differences in hydrology cause gradie ...[more]

PMID: 33505383

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Dataset Information

Temporal, Spatial, and Temperature Controls on Organic Carbon Mineralization and Methanogenesis in Arctic High-Centered Polygon Soils.

Publications

Temporal, Spatial, and Temperature Controls on Organic Carbon Mineralization and Methanogenesis in Arctic High-Centered Polygon Soils.

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