再论华南地区末次冰盛期植被类型

ADDITIONAL REMARKS ON VEGETATION TYPES IN SOUTH CHINA DURING THE LAST GLACIAL MAXIMUM (LGM)

根据南海北部17940孔和台湾中部头社孔孢粉序列对比结果,首次提出了华南地区15—40kaBP期间的三个具代表性植物群1)以青栲类为主的亚热带常绿阔叶林为第1植物群,该植物群在MIS2阶段(20—15kaBP),为南海北部周边地区和台湾中部头社盆地周围地带性植被;2)以松属或桤木属为主的木本植物为第2植物群,对应于间冰阶,夏季风盛行,降水充沛,气候暖湿,高海面(高湖面);3)以蒿属或以禾草为主的草本植物为第3植物群,对应于冰阶,冬季风盛行,降水少,气候暖干,低海面(低湖面)。第2、3植物群在末次冰期时段呈交替出现,表现出东亚季风在本区的旋回特征。文中推论了LGM时段大陆架上的植被类型为陆架前缘的浅水区分布着红树林,裸露的陆架前后缘分别生长着草地、灌木丛和常绿阔叶林。最后,本文提出了蒿属峰值与北大西洋Heinrich事件的对比。

A comparative study of pollen floras between two cores. Core 17940 from the northern slope of the South China Sea and a core from the Toushe Basin in central Taiwan Province, reveals that there were three different vegetation types around the two areas during 15-40 kaBP. The first type is characterized with the subtropical evergreen broadleaved forest during MIS2（20-15 kaBP）. The second is the Pinus/ Alnus-dominated woody plant communitites, corresponding to an interstadial summer monsoon dominated warm and humid climate and higher sea/lake level. The third is the Artemisia/Poaceae（Graminae）-dominated herb communities, corresponding to a stadial winter monsoon dominated warm and dry climate and lower sea/lake level. Alternation of the second and the third vegetation patterns implies cycles of the Asian Monsoon. During the LGM, there were several vegetation types on the northern continental shelves in the South China Sea such as mangrove stands distributed in shallow sea in the front, grassland and shrubs at the front bare parts with the evergreen broadleaved forest behind. The peaks of Artemisia could be comparable to Heinrich events（H events）in the North Atlantic.