Spatiotemporal patterns of carbon sequestration in a large shallow lake, Chaohu Lake: Evidence from multiple-core records
Spatiotemporal patterns of carbon sequestration in a large shallow lake, Chaohu Lake: Evidence from multiple-core records
复制标题
巢湖大型浅湖碳固存时空格局：来自多核记录的证据
DOI：
10.1016/j.limno.2020.125748
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发表时间：
2020-03-01
期刊：
影响因子：
1.7
通讯作者：
Yang, Xiangdong
中科院分区：
文献类型：
--
作者：
Sun, Kangkang;Chen, Xu;Yang, Xiangdong
湖泊沉积物能够封存大量碳，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（或少数几个）沉积柱记录，因此可能低估了单个湖泊内碳埋藏特征的变异性。所以在本研究中，选择长江中下游典型的大型浅水湖泊巢湖进行多个高分辨率沉积柱研究以阐明这种变异性。总共根据古湖沼学指标分析了18个沉积柱（包括对3个主沉积柱进行的铅 - 210/铯 - 137分析）；对大多数沉积柱测量或估算了沉积速率、总有机碳、粒度和烧失量。研究了有机碳埋藏速率（OCBR）、碳储量及其驱动因素的时空变化。结果表明：1）在过去150年中，碳埋藏存在明显的时间差异，OCBR从1.1克碳/平方米/年变化到25.6克碳/平方米/年（平均9.8克碳/平方米/年）。OCBR在1900年左右开始增加，20世纪50年代之后快速增加，20世纪70年代之后呈下降趋势。自19世纪50年代以来，该湖泊的总碳埋藏量（OCBA）为1.11×10¹⁰克。2）湖泊西北区域6个沉积柱的平均OCBR为13.4克碳/平方米/年，显著高于其他区域沉积柱的OCBR（9.6克碳/平方米/年）。3）所有18个沉积柱中的总有机碳、OCBR、OCBA都呈现出相似的时间模式（即大多数沉积柱自20世纪50年代以来显著增加），但在湖泊的几个位置存在显著差异。4）根据显著的相关性，在过去150年中，巢湖的碳埋藏似乎受到区域温度和人口规模变化的极大影响。OCBR与过去50年的平均湖泊水位也有显著相关性，这表明人类活动（特别是修建水坝）对巢湖的OCBR产生了重要影响。这项多沉积柱研究揭示了湖泊碳埋藏的时空特征，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。
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 Pb-210/Cs-137 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/m(2)/y to 25.6 g C/m(2)/y (mean 9.8 g C/m(2)/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 10(10) g. 2) The average OCBR of six sediment cores in the northwest lake area is 13.4 g C/m(2)/y, significantly higher than that for sediment cores in other areas (9.6 g C/m(2)/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.