南海永暑礁微型软体动物对晚全新世快速气候变化的响应

近2000年来的地球环境变化日益受到人们的关注,许多替代指标被用来指示快速的气候变化。本文试图通过南海永暑礁泻湖微型软体动物丰度和分异度的研究及其与北半球温度异常的对比,来阐述微型软体动物对快速气候变化的响应。研究表明,软体动物丰度变化的三个高值和三个低值较好地对应于北半球温度异常,显示了微型软体动物丰度对快速气候变化的灵敏反应。尤其重要的是“小冰期”和“中世纪暖期”被证明在南海也发生过。这表明快速的气候变化事件也会影响到热带海区。研究还证实另一次温暖的气候事件发生在大约 850A.D.—680A.D.之间。文中对软体动物分异度与气候变化的关系也作了探讨,并表明软体动物丰度和分异度是指示气候变化的有用指标。

MICROMOLLUSK RESPONSE TO THE LATE HOLOCENE RAPID CLIMATIC VARIABILITY IN THE YONGSHU REEF, SOUTH CHINA SEA

Environmental variability in the last 2000 years has recently received much attetion and has been studied with many proxies. We studied variability in micromollusk abundance and diversity in the Yongshu reef lagoon (South China Sea) in the late Holocene, and their relationship with the temperature record of the Northern Hemi- sphere, in order to document the micromollusk response to climatic variability on shorter timescales. The variability in micromollusk abundance shows three high values and three low values which correspond to the temperature anom-aly of the Northern Hemisphere, documenting that the micromollusk abundance is sensitive to rapid climatic change. Particularly attention is paid to "Little Ice Age" and "Medieval Warm Period" that are demonstrated to occur in the South China Sea. This indicates that these climatic events exerted influence on sea area around tropic zone. Research also finds that there was another event of warm climatic event which occurred in this area between about 850 A. D. and 680 A. D. This paper also discusses relationship between mollusk diversity and rapid climatic change and states that micromollusks are a valuable proxy record in indicating climatic changes.