摘要
程海为富营养化封闭湖泊。通过对程海 CH0 1孔沉积物色素分析 ,定性恢复了近 5 0 0 a来程海湖泊初始生产力演化过程。结果表明 ,近 5 0 0 a来程海湖泊初始生产力总体上呈现由低到高的上升趋势。其中 170 0 AD前后、1790 AD前后是湖泊初始生产力出现变化的界限。另外 ,色素含量变化揭示研究时期内存在 175 0 AD前后、1930
Chenghai Lake,a closed eutrophic lake,is situated in Yunnan Plateau.Here the primary productivity trends of the Chenghai lake for the past 500 years were reconstructed by using sediment pigments from core CH01.Oscillaxanthin (Osc)is a pigment unique to the Oscillatoriaceae and has been found in only one genus apart from Oscillatoria .In contrast,Myxoxanthophyll (Myx) is found in most blue green algal genera and in all six families examined.The Chlorophyll derivatives (CD)and total carotenoids (TC) are frequently used in palaeolimnology to reconstruct past levels of primary productivity.In the Chenghai Lake core,the most obvious stratigraphic change in pigment concentration is the dramatic rise in Oscillaxanthin and Myxoxanthophyll beginning at 15 cm. Moreover,high CD and TC values following high Myx and Osc values above 45 cm,allude to higher production.However,high CD and TC values and relatively lower Myx and Osc and CD/TC,correlate with good preservation. During the last 500 years,Chenghai Lake has undergone major increases in productivity and eutrophication in response to the variations in the lake level from agriculture in the lake's watershed.The results showed that the primary productivity generally increased for the recent 500 years,during which there were two abrupt transitions at about 1700 and 1790AD respectively.In addition,from pigment evidences two warm events were demonstrated at about 1750 and 1930AD respectively.
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2002年第2期95-98,共4页
Marine Geology & Quaternary Geology
基金
国家自然科学基金资助项目 (4 980 3 0 0 1)
中科院知识创新工程重大项目 (KZCX1-10 -0 2 )
