Stable isotopes reveal independent carbon pools across an Arctic hydro-climatic gradient: Implications for the fate of carbon in warmer and drier conditions
Stable isotopes reveal independent carbon pools across an Arctic hydro-climatic gradient: Implications for the fate of carbon in warmer and drier conditions
复制标题
稳定同位素揭示了北极水文气候梯度上的独立碳库：对温暖和干燥条件下碳命运的影响
DOI：
10.1002/lol2.10119
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发表时间：
2019
影响因子：
7.8
通讯作者：
Osburn C
中科院分区：
文献类型：
--
作者：
Osburn C
在不久的将来，北极湖泊的碳(C)循环将发生重大变化。湖泊中的原地过程消耗了无机碳，并产生了可以隔离在沉积物中的生物量，伴随着来自周围分水岭的异地输入的有机物质。这两种碳源都可以矿化并以二氧化碳的形式脱气，但也会变得顽固并积累在远洋水域。利用稳定碳同位素(δ13C)值和元素比值作为地球化学指标，研究了格陵兰西南部水文气候梯度湖泊的不同有机质来源。颗粒有机质(POM)和沉积物明显为原生藻类来源，而溶解有机物(DOM)则是原生大型植物和异地分水岭来源的混合体。我们的结果表明，更温暖和更干燥的北极将导致解耦的碳池：水柱由越来越多的原生、大型植物DOM主导，沉积物以原生藻类POM为主。
Arctic lakes are poised for substantial changes to their carbon (C) cycles in the near future. Autochthonous processes in lakes which consume inorganic C and create biomass that can be sequestered in sediments are accompanied by allochthonous inputs of organic matter from the surrounding watershed. Both C sources can be mineralized and degassed as CO2, but also become recalcitrant and accumulate in pelagic waters. Using stable carbon isotope (δ13C) values and elemental ratios as geochemical proxies, we investigated diverse organic matter sources to lakes located across a hydro‐climatic gradient in Southwest Greenland. Particulate organic matter (POM) and sediments were clearly of autochthonous algal origin, while dissolved organic matter (DOM) was a mix between autochthonous macrophytes and allochthonous watershed sources. Our results imply that a warmer and drier Arctic will lead to decoupled C pools: a water column dominated by increasingly autochthonous, macrophytic DOM, and sediments dominated by autochthonous algal POM.