|ZHANG Fengju,XUE Bin,YAO Shuchun.Organic carbon burial and its driving mechanism in the sediment of Lake Hulun, northeastern Inner Mongolia, since the mid-Holocene. J. Lake Sci.2018,30(1):234-244. DOI:10.18307/2018.0123
|通过对内蒙古高原呼伦湖沉积物样品总有机碳含量（TOC）及其稳定同位素（δ13Corg）、总氮含量（TN）和TOC/TN （C/N）值的测定，结合沉积岩芯AMS14C年代标尺，分析了中全新世以来呼伦湖沉积物有机碳埋藏速率随时间变化的趋势及有机质的来源，并探讨了影响呼伦湖有机碳埋藏的主要因素.结果表明，中全新世以来呼伦湖有机碳埋藏速率平均值约为2.06 g/（m2·a），碳储量约为35.25 Tg C，且总体上呈现增加趋势.呼伦湖沉积物中有机质主要来源于外源输入，但近1000 a以来内源输入逐渐增加并占据优势.呼伦湖有机碳埋藏速率与温度和降水均呈负相关，表明在长时间尺度上，升温及降水量的增加可能对呼伦湖的碳埋藏起到一定的抑制作用.
|关键词: 碳储量 温度 降水 总有机碳 稳定同位素 呼伦湖
|Organic carbon burial and its driving mechanism in the sediment of Lake Hulun, northeastern Inner Mongolia, since the mid-Holocene
ZHANG Fengju1,2, XUE Bin1, YAO Shuchun1
1.State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China;2.University of Chinese Academy of Sciences, Beijing 100049, P. R. China
|A sediment core (HL16) was collected in the central part of Lake Hulun in northeastern Inner Mongolia using a piston core sampler. The total organic carbon (TOC) content and its stable isotope (δ13Corg), total nitrogen (TN) content and the total organic carbon and nitrogen (C/N) ratio of sediments were analyzed to investigate the temporal changes of organic carbon burial and its driving factors, as well as the organic carbon (OC) sources over the mid-Holocene. The OC burial rate presented an overall increasing trend for the last 7400 years, and the average OC burial rate was about 2.06 g/(m2·a), with a total C pool of 35.25 Tg C. Relative contributions of allochthonous and autochthonous OC input were estimated using a binary model, suggesting that OC being buried in Lake Hulun was mainly generated from terrigenous vegetation. The binary model also revealed that autochthonous OC demonstrated an increasing trend in the last 1000 years. The OC burial rate was negatively linked to temperature and precipitation based on Pearson analysis, implying that the increase in temperature and precipitation might lead to the decrease of OC burial in Lake Hulun in the long term scale.
|Key words: Carbon storage temperature precipitation total organic carbon stable isotope Lake Hulun