Stable isotope records of plant cover change and monsoon variation in the past 2200 years: evidence from laminated stalagmites in Beijing, China
Stable isotope records of plant cover change and monsoon variation in the past 2200 years: evidence from laminated stalagmites in Beijing, China
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DOI：
10.1080/03009480310002000
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发表时间：
2003-01-01
期刊：
影响因子：
2.2
通讯作者：
Liu, TS
中科院分区：
文献类型：
--
作者：
Hou, JZ;Tan, M;Liu, TS
对采自北京西南郊石花洞的两个石笋进行了年层计数。结果与热电离质谱法Th-230测年结果一致。石笋稳定碳同位素的变化主要受植被覆盖度变化的影响，植被覆盖度变化在很大程度上反映了气候变化和季风变化。氧同位素主要受降水的影响，降水与夏、冬季风强度有关。因此，碳和氧同位素的组合可以作为植被变化和季风变化的代理。我们的稳定同位素结果表明，较低的碳同位素值的石笋在公元前200年和公元1000年可能意味着密集的植物覆盖和一个插曲，由潮湿的夏季风为主。从公元1000年到公元1450年，主导季风在冬季风和夏季风之间交替。自近似于AD 1450年以来，碳同位素比值和氧同位素比值的显着跳跃已被证明，表明植物覆盖减少和干燥的冬季风可能占主导地位。结果与该地区的历史文献相一致。
Two stalagmites collected from the Shihua cave in the southwestern suburb of Beijing were dated by annual layer counting. The results are consistent with thermal ionization mass spectrometry Th-230 dating. Stable carbon isotope variation of stalagmites is dominated by plant cover change, which largely reflects climate change and monsoon variation. Oxygen isotopes are mainly affected by precipitation, which is related to summer and winter monsoon intensity. The combination of carbon and oxygen isotopes can therefore be a proxy of plant cover change and monsoon variation. Our stable isotope results show that lower carbon isotope values of the stalagmites between 200 BC and AD 1000 probably imply dense plant cover and an episode dominated by humid summer monsoon. From similar to1000 to AD 1450, the dominant monsoon alternated between the winter monsoon and the summer monsoon. Since similar toAD 1450, a significant jump in carbon isotope ratios and increasing oxygen isotope ratios has been demonstrated, indicating less plant cover and the probable dominance of dry winter monsoon. The results are consistent with historical documents of the region.