The early Holocene optimum inferred from a high-resolution pollen record of Huguangyan Maar Lake in southern China  

作　　者：WANG ShuYun LUE HouYuan LIU JiaQi Joerg F. W. NEGENDANK 

机构地区：[1]Institute of Geology and GeophysicS, Chinese Academy of Sciences, Beijing 100029, China [2]GeoForschungsZentrum (GFZ), Section 3.3, Telegrafenberg, Potsdam D-14473, Germany

出　　处：《Chinese Science Bulletin》2007年第20期2829-2836,共8页

基　　金：Supported by the National Natural Science Foundation of China for Distinguished Youth Scholar (Grant No. 40325002);the Key Research Project of the Knowledge Innovation Program of CAS (Grant Nos. KZCX3-SW-145 and KZCX2-YW-117);the National Basic Research Program of China (Grant No. 2005CB422002-2);the National Natural Science Foundation of China (Grant No. 40331011)

摘　　要：A high-resolution pollen record of the past 13000 a from Huguangyan Maar Lake reveals the vegetation and environment changes in southern China during the Holocene. It shows that (i) pollen percentage of trees and shrubs reached 56% during the early Holocene (11600―7800 cal a BP), of which the pollen percentage of tropical trees reached a maximum at 9500―8000 cal a BP, reflecting a hot and wet envi- ronment; (ii) during the mid-Holocene (7800―4200 cal a BP), the pollen percentage of montane conif- erous trees and herbs increased, while the percentage of tropical-subtropical trees decreased, indi- cating lower temperature and humidity; (iii) in the late Holocene spanning from 4200 to 350 cal a BP, the pollen percentage of herbs and montane conifer increased significantly, indicating a marked decrease of temperature and humidity. Our pollen data reveal that the time period 9500―8000 cal a BP in south- ern China represents a climatic optimum for the Holocene characterized by hot and wet conditions. This is consistent with the Holocene optimum found in lower latitude regions globally. We speculate that strong insolation might cause the northward migration of the ITCZ and subtropical summer mon- soon front, which resulted in an early Holocene optimum in the Huguangyan area. The dry tendency and climate fluctuations of the middle and late Holocene could be associated with a decrease in solar insolation and frequent ENSO event.A high-resolution pollen record of the past 13000 a from Huguangyan Maar Lake reveals the vegetation and environment changes in southern China during the Holocene. It shows that （i） pollen percentage of trees and shrubs reached 56% during the early Holocene （11600-7800 cal a BP）, of which the pollen percentage of tropical trees reached a maximum at 9500-8000 cal a BP, reflecting a hot and wet environment; （ii） during the mid-Holocene （7800-4200 cal a BP）, the pollen percentage of montane coniferous trees and herbs increased, while the percentage of tropical-subtropical trees decreased, indicating lower temperature and humidity; （iii） in the late Holocene spanning from 4200 to 350 cal a BP, the pollen percentage of herbs and montane conifer increased significantly, indicating a marked decrease of temperature and humidity. Our pollen data reveal that the time period 9500-8000 cal a BP in southern China represents a climatic optimum for the Holocene characterized by hot and wet conditions. This is consistent with the Holocene optimum found in lower latitude regions globally. We speculate that strong insolation might cause the northward migration of the ITCZ and subtropical summer monsoon front, which resulted in an early Holocene optimum in the Huguangyan area. The dry tendency and climate fluctuations of the middle and late Holocene could be associated with a decrease in solar insolation and frequent ENSO event.

关 键 词：全新世时期 最适度 花粉分析 中国南部 

分 类 号：Q1-0[生物学—普通生物学]