Abstract Lake sediment can sequestrate large amounts of carbon and this issue has become a research hotspot. However, most of research on carbon burial in lakes is based on a single (or a few) sediment core records and so may underestimate the variability of carbon burial features within a single lake. In this study, therefore, Chaohu Lake, a typical large shallow lake in the middle and lower reaches of the Yangtze River, was selected to conduct multiple, high resolution sediment core studies to elucidate that variability. Overall 18 sediment cores are analyzed according to paleolimnological proxies (including 210Pb/137Cs for 3 master cores); sediment accumulation rate, total organic carbon, grain size and loss of ignition is measured or estimated for most cores. The spatiotemporal variations of organic carbon burial rate (OCBR), carbon storage and their driving factors were examined. Results show: 1) There was a clear temporal difference in carbon burial during the past 150 years, with OCBR varying from 1.1 g C/m2/y to 25.6 g C/m2/y (mean 9.8 g C/m2/y). OCBR began to increase after around 1900, a rapid increase followed after 1950s and a downward trend after 1970s. Total carbon burial amount (OCBA) in the lake since the 1850s is 1.11 x 1010 g. 2) The average OCBR of six sediment cores in the northwest lake area is 13.4 g C/m2/y, significantly higher than that for sediment cores in other areas (9.6 g C/m2/y). 3) TOC, OCBR, OCBA in all 18 cores exhibited similar temporal patterns (i.e. marked increase since 1950s in most of the cores) but with significant differences in several lake locations. 4) During the last 150 years, carbon burial in Chaohu Lake appears to be greatly affected by changes in regional temperature and population size, according to their significant correlations. OCBR also has a significant correlation with the average lake level in the past 50 years, indicating human activity (notably dam building). This has imposed an important impact on OCBR in Chaohu Lake. This multi-sediment core study reveals the spatiotemporal characteristics of carbon burial in the lake and provides an important basis for increasing the accuracy of calculating carbon storage in large shallow lakes.

中文翻译：

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巢湖大型浅湖固碳时空模式：来自多核记录的证据

摘要 湖泊沉积物可固存大量碳，这一问题已成为研究热点。然而，大多数关于湖泊碳埋藏的研究是基于单个（或少数）沉积物核心记录，因此可能低估了单个湖泊内碳埋藏特征的变异性。因此，本研究选择了长江中下游典型的大型浅湖巢湖进行多项高分辨率沉积岩心研究，以阐明这种变异性。根据古湖泊学代理分析了总共 18 个沉积物岩心（包括 3 个主岩心的 210Pb/137Cs）；大多数岩心都测量或估计了沉积物积累率、总有机碳、颗粒大小和失火量。有机碳埋藏率（OCBR）的时空变化，研究了碳储存及其驱动因素。结果表明：1）过去150年碳埋藏存在明显的时间差异，OCBR从1.1 g C/m2/y变化到25.6 g C/m2/y（平均9.8 g C/m2/y）。OCBR在1900年左右开始上升，1950年代后迅速上升，1970年代后呈下降趋势。自 1850 年代以来，湖中的总碳埋藏量 (OCBA) 为 1.11 x 1010 g。2）西北湖区6个沉积岩心的平均OCBR为13.4 g C/m2/y，明显高于其他地区（9.6 g C/m2/y）。3) 所有 18 个核心的 TOC、OCBR、OCBA 表现出相似的时间模式（即自 1950 年代以来大多数核心显着增加），但在几个湖泊位置存在显着差异。4) 在过去的 150 年里，巢湖碳埋藏似乎受区域温度和人口规模变化的影响很大，根据它们的显着相关性。OCBR 还与过去 50 年的平均湖泊水位显着相关，表明人类活动（特别是大坝建设）。这对巢湖的OCBR产生了重要影响。该多沉积物岩心研究揭示了湖泊中碳埋藏的时空特征，为提高大型浅水湖泊碳储量计算的准确性提供了重要依据。这对巢湖的OCBR产生了重要影响。该多沉积物岩心研究揭示了湖泊中碳埋藏的时空特征，为提高大型浅水湖泊碳储量计算的准确性提供了重要依据。这对巢湖的OCBR产生了重要影响。该多沉积物岩心研究揭示了湖泊中碳埋藏的时空特征，为提高大型浅水湖泊碳储量计算的准确性提供了重要依据。