孢粉、炭屑揭示的黔西高原MIS3b期间古植被、古气候演变  

MIS3b vegetation and climate changes based on pollen and charcoal on Qianxi Plateau

作　　者：赵增友[1] 袁道先[1,2] 石胜强[1] 罗伦德[1] 

机构地区：[1]西南大学地理科学学院,重庆400715 [2]中国地质科学院岩溶地质研究所,桂林541004

出　　处：《生态学报》2012年第15期4811-4818,共8页Acta Ecologica Sinica

基　　金：国土资源部;广西壮族自治区岩溶动力学重点实验室开放课题基金项目(KDL2008-15);国家自然基金(41072141);西南大学科技创新项目(ky2011004);西南大学青年基金项目(swu208001)

摘　　要：将孢粉与炭屑结合应用于贵州盘县坪地晚更新世剖面,对比高分辨率的NGRIPδ18O、石笋记录分析,用以揭示黔西高原MIS3b期古植被、古气候演变。结果显示:45.16—44.44 ka BP期间,孢粉缺失,炭屑少,说明此时植被稀少,气候寒冷,可能指示H5事件。44.44—44.04 ka BP期间,以禾本科、百合科为主的草本及喜冷湿的蕨类占优势,乔、灌木稀少。炭屑浓度低,但末期出现峰值,说明气候开始由冷湿向温干过渡。44.04—42.5 ka BP期间,禾本科草类继续增加,成为草原植物的主要成分;乔木种类增加,但含量不高。炭屑浓度高,峰值频繁出现,指示气侯温干。42.5—41.29 ka BP期间,草原萎缩,森林面积扩展。针叶、常绿及落叶阔叶林迅速扩展。炭屑浓度总体偏低稳定,指示该时期气候温凉湿润。总之,MIS3b整体较冷,干湿交替出现。Climate and vegetation changes during marine isotope stage 3b （MIS3b） are a major focus of Quaternary research. The vegetation on the western Guizhou plateau, part of the Yungui Plateau in China, is highly sensitive to climate changes and thus represents a potential environmental archive. We obtained a 13-m-long sediment sequence from Pan County of Guizhou Province and analyzed the range corresponding to 45-41 ka（ 10-12.85 m）. Pollen date, charcoal concentration, and four accelerator mass spectroscopy （AMS） 14C dates （only three are available） were obtained. We used the three AMS14C dates （without calibration） to establish an age model and compared pollen and charcoal data with oxygen isotope records from ice cores from North Greenland and the Tibetan plateau and with a stalagmi （12.85--12.50 m, 45. 16--44.44 ka） had sparse charcoal concentration. This period may correspond to te from Hulu Cave, China. The results indicated that pollen zone A vegetation and a cold climate, as reflected by the low pollen and the H5 event. Pollen zone B （ 12.50-12.2 m, 44.44-44.04 ka） was characterized by pollen of Gramineae, Cupressaceae, Liliaceae, and Davalliaceae and acted as a transient period. Herbs and ferns were dominant in this zone, indicating that the temperature was warmer than in zone A, but still cold. The charcoal concentration in zone B was low, but a peak implied fire activity （fire suggests dry conditions）. Pollen of thesetaxa, especially Gramineae, herbs, and ferns, increased significantly in abundance in zone C （ 12.20-11.15 m, 44.04- 42.5 ka）. Pollen of trees and shrubs, including Pinus, Quercus, Abies, Ulmus, Salix, Corylus, and Betula, were increasing in abundance, but their percentages were still low. Frequent peaks of micro-charcoal concentration indicated regional fire activity. Hence, the climate was warmer and drier in zone C than in zone B. The composition of the ecosystem changed substantially in pollen zone D （11.15--10.45 m, 42.5--41.29 ka）. Trees and shrubs c

关 键 词：黔西高原 孢粉 炭屑 古气候 古植被 

分 类 号：Q914[天文地球—古生物学与地层学]