14,000-year carbon accumulation dynamics in a Siberian lake reveal catchment and lake productivity changes
International audience A multi-proxy paleolimnological analysis of a sediment core sequence from Lake MalayaChabyda in Central Yakutia (Eastern Siberia, Russia) was conducted to investigatechanges in lake processes, including lake development, sediment and organic carbonaccumulation, and changes in...
Published in: | Frontiers in Earth Science |
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Main Authors: | , , , , , , , , , , , , , , |
Other Authors: | , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2021
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Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-03453509 https://hal.archives-ouvertes.fr/hal-03453509/document https://hal.archives-ouvertes.fr/hal-03453509/file/Hughes-Allen_2021_FrontiersEarthSc%283%29.pdf https://doi.org/10.3389/feart.2021.710257 |
Summary: | International audience A multi-proxy paleolimnological analysis of a sediment core sequence from Lake MalayaChabyda in Central Yakutia (Eastern Siberia, Russia) was conducted to investigatechanges in lake processes, including lake development, sediment and organic carbonaccumulation, and changes in primary productivity, within the context of Late Pleistoceneand Holocene climate change. Age-depth modeling with 14C indicates that the maximumage of the sediment core is ∼14 cal kBP. Three distinct sedimentary units were identifiedwithin the sediment core. Sedimentological and biogeochemical properties in the deepestsection of the core (663–584 cm; 14.1–12.3 cal kBP) suggests a lake environment mostlyinfluenced by terrestrial vegetation, where organic carbon accumulation might have beenrelatively low (average ∼100 g OC m−2 a−1), although much higher than the global modernaverage. The middle section of the core (584–376 cm; 12.3–9.0 cal kBP) is characterizedby higher primary productivity in the lake, much higher sedimentation, and a remarkableincrease in OC delivery (average ∼300 g OC m−2 a−1). Conditions in the upper section ofthe core (<376 cm; < 9.0 cal kBP) suggest high primary productivity in the lake and highOC accumulation rates (average ∼200 g OC m−2 a−1), with stable environmentalconditions. The transition from organic-poor and mostly terrestrial vegetation inputs(TOC/TNatomic ratios ∼20) to conditions dominated by aquatic primary productivity(TOC/TNatomic ratios <15) occurs at around 12.3 cal kBP. This resulted in an increasein the sedimentation rate of OC within the lake, illustrated by higher sedimentation ratesand very high total OC concentrations (>30%) measured in the upper section of the core.Compact lake morphology and high sedimentation rates likely resulted in this lake acting asa significant OC sink since the Pleistocene-Holocene transition. Sediment accumulationrates declined after ∼8 cal k BP, however total OC concentrations were still notably high.TOC/TNatomic and isotopic data ... |
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