Carbon sink potential of eutrophic lake sediments: a reconstruction of the potntial in lakes Nakaumi and Shinji during the last about four hundred years

富营养化湖泊沉积物的碳汇潜力：近四百年来中海湖和真道湖碳汇潜力的重建

• 批准号: 22540470
• 负责人: SAMPEI Yoshikazu
• 金额: $ 3.16万
• 依托单位: Shimane University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2010
• 资助国家: 日本
• 起止时间: 2010 至 2012
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-22540470/
• 关键词: 汽水域; 有機物濃度; 有機炭素埋積速度; 二酸化炭素; 硫化水素; カーボンシンク; 中海; 宍道湖; 富栄養湖; 中海・宍道湖; サプロペル

Carbon sink potential of eutrophic lake sediments from lakes Nakaumi and Shinji was studied for recent and several hundred years environments using surface sediments and sediment cores.TOC (total organic carbon) contents of southern and central L. Nakaumi showed high sapropelic about 3.6~4.0% in the 1cm surface sediments. These values are constant from AD1997. TOC contents of all samples from L. Shinji showed also sapropelic and high about 3.5~4.3% except for eastern part. These TOC values in L. Shinji are not changed during the last 5 years. According to the result of C/N ratio (7-9) and py-GC-MS, origin of organic matter in both lakes is supposed to be predominant phyto-plankton. Sediment cores showed low TOC contents about 1% between AD1800 and 1900 in both L. Nakaumi and Shinji and TOC contents drastically increased from 1% to 4% after AD1900. Analysis of AD2003 data by our preliminary research indicates that TOC contents over 3.5% of surface sediments have a good positive correlat … More ion with H2S (ppm), showing an equation: H2S (ppm) = 13.9 * TOC (%) - 52.1 (TOC>3.5%). Atmospheric CO2 concentration on the northeastern Nakaumi was low about 360 ppm in average (April to May, 2013), which could depend on spring blooming of phyto-plankton. Impressive difference of the CO2 concentration between daytime and nighttime was up to 80 ppm. Average OCARs in the surface sediments of L. Nakaumi and Shinji are 7.0 mgC/cm2/y and 4.0 mgC/cm2/y，respectively based on the sedimentation rate reported by Kanai et al., (1998, 2002). As a result, L. Nakaumi and Shinji have a potential carbon sink of about 6,000 tonC/y and 3,200 tonC/y, respectively. Low OCARs of the cored sediments with low TOC about 1% in L. Nakaumi during 50-25 cm (1770-1890) and TOC about 0.7% in L. Shinji during 30-20cm (1830-1890), i.e. Little Ice Age, suggested 2,000 tonC/y and 1,300 tonC/y, respectively. These low values during cool climate are about one - third of the present potential. These brackish lakes are characterized as a quick response carbon sink for climate change. Less

利用表层沉积物和沉积岩心研究了中海湖和真道湖富营养化湖泊沉积物的碳汇潜力，研究了最近和数百年的环境。中海湖南部和中部的TOC（总有机碳）含量表现出较高的腐泥性，约为3.6~4.0%在 1cm 表面沉积物中，这些值自公元 1997 年以来一直是恒定的，L. Shinji 的所有样品的 TOC 含量也显示出腐泥性和高约。根据C/N比(7-9)和py-GC-MS的结果，除东部地区外，这些TOC值在3.5~4.3%之间没有变化。两个湖泊中的有机质被认为是主要的浮游植物，在公元 1800 年至 1900 年期间，L. Nakaumi 和 Shinji 的沉积物核心显示出约 1% 的 TOC 含量，并且 TOC 含量急剧下降。我们对AD2003年数据的初步研究表明，超过3.5%的表层沉积物TOC含量与H2S（ppm）有良好的正相关性，由方程：H2S（ppm） = 13.9 * TOC (%) - 52.1 (TOC>3.5%) 中海东北部的大气二氧化碳浓度较低。平均 360 ppm（2013 年 4 月至 5 月），这可能取决于春季浮游植物的繁盛，L. Nakaumi 和 L. Nakaumi 表面沉积物中二氧化碳浓度的显着差异高达 80 ppm。 Shinji 分别为 7.0 mgC/cm2/y 和 4.0 mgC/cm2/y，基于 Kanai 报告的沉降速率L. Nakaumi 和 Shinji 等人（1998 年，2002 年）的结果是，TOC 较低的沉积物的潜在碳汇分别约为 6,000 吨C/年和 3,200 吨C/年。 L. Nakaumi 在 50-25 cm (1770-1890) 期间，TOC 约为 0.7%。 Shinji 在 30-20 厘米（1830-1890），即小冰河时期，分别建议 2,000 吨C/年和 1,300 吨C/年，这些在凉爽气候期间的低值大约是这些咸水湖泊目前潜力的三分之一。被描述为气候变化的快速反应碳汇。

项目成果

中海における底質表層の全有機炭素濃度の変化

中海底部沉积物表层总有机碳浓度变化

• 发表时间: 2012
• 作者: Amm;O.;R. Fujii;K. Kauristie;A. Aikio;A. Yoshikawa;A. Ieda;and H. Vanhamaki;富樫 均・原山 智・北野 聡;植田勇人・臼杵直・平内健一・三浦亮・YK10-13Leg2乗船研究者一同;三瓶良和
• 通讯作者: 三瓶良和