湖泊科学2019，Vol.31Issue(1)：282-292,11.DOI:10.18307/2019.0126
近百年来洱海沉积物有机碳埋藏时空变化
Spatio-temporal patterns of organic carbon burial in the sediment of Lake Erhai in China during the past 100 years
摘要
Abstract
Organic carbon (OC) burial in lake sediments plays important roles in the terrestrial carbon cycle and global carbon balance. Lake Erhai is the second largest freshwater lake in the Yunnan-Guizhou Plateau. There have been many studies on the changes in the lake ecological environment and pollution of trace metals and nutrients, but limited knowledge is available on the spatiotemporal patterns in OC burial in sediment. Based on the analysis of OC content in core EH2012 and other 13 sedimentary cores in Lake Erhai, the characteristics in temporal and spatial variations of OC burial in recent 100 years were studied, and their relationships with the climatic, anthropogenic and ecological factors were discussed. The C/N molar ratio indicated that the sedimentary OC in Lake Erhai were mainly autochthonous in source, and they displayed similar vertical trends in the cores from different lake areas. In core EH2012, for example, the OC content displayed three stages variations. The OC content were low before 1970 AD, followed by a gradual increase between 1970 and 2000 AD, then increased sharply after 2000 AD and reached the maxima in recent years. The organic carbon accumulation rate (OCAR) increased gradually over the past 100 years as shown in core EH2012, and ranged from 7. 9 to 87. 2 g/ (m2·a), with an average value (OCAR) of 24.1 g/ (m2·a). The OCAR variations in cores EH2012 were positively correlated with the OC content and regional temperature, suggesting that the enhancing lake primary productivity driven by both nutrients levels and temperature should be one of major factors responsible for rising OCAR. Using the 1982 chronology mark established by initial time of Cd pollution in the cores, the OCAR since 1982 AD showed large diversity in different lake areas, ranging from 17.1 to 44.7 g/ (m2·a), and it averaged 31.4 g/ (m2·a) for the whole lake based on the Kriging interpolation. The spatial variation in OCAR is positively correlated with the phosphorus accumulation rate, which also suggests the driving mechanism of nutrient levels on the OC burial.关键词
洱海/沉积物/有机碳埋藏/时空变化/驱动机制Key words
Lake Erhai/sediment/organic carbon burial/spatio-temporal variations/driving mechanism引用本文复制引用
刘会基,刘恩峰,于真真,张恩楼,林琪,王荣,沈吉..近百年来洱海沉积物有机碳埋藏时空变化[J].湖泊科学,2019,31(1):282-292,11.基金项目
国家科技基础性工作专项(2014FY110400) （2014FY110400）
国家自然科学基金项目(41672354,41271214)联合资助 （41672354,41271214）
