乌兰布和沙漠钻孔WL10ZK-1孢粉记录的末次冰期以来的植被变化
THE VEGETATION CHENGES IN ULAN BUH DESERT SINCE THE LAST GLACIAL: POLLEN EVIDENCE FROM CORE WL10ZK-1
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摘要: 根据乌兰布和沙漠北部25 m钻孔(WL10ZK-1)岩心的孢粉记录,结合OSL测年结果,初步讨论了乌兰布和沙漠地区的植被变化。结果表明,90 kaBP以前,钻孔岩心为粉砂质泥,孢粉中出现香蒲花粉(最高达12%),并有较高的云杉(最高为22.5%)、禾本科和莎草科花粉,说明当时属于湖泊状态,以草原植被为主;90 kaBP以来,乌兰布和沙漠以藜科,蒿属及柽柳和蒺藜科等旱生/盐生灌木为主,属于典型荒漠植被;8 kaBP前后,孢粉谱中出现较高松属花粉,形成以蒿属花粉为主的草原植被。结合岩心信息,孢粉记录说明,90 kaBP之前和8 kaBP前后,乌兰布和沙漠主要为草原植被,周围山地生长有针叶树,末次冰期则主要为荒漠植被。Abstract: The paleo-vegetation changes of the Ulan Buh Desert since last Glacial are discussed according to the lithology, chronology and pollen analyses of the drill core WL10ZK-1.The high content of Typha pollen (up to 12%), and a quantity of Picea (up to 22.5%), Poaceae and Cyperaceae pollen from the bottom of drill core indicate that there was a lacustrine environment with steppe vegetation in the Ulan Buh Desert before 90 ka. Since 90 ka, xerophytic/halophyte herbs or shrubs such as Chenopodiaceae,Artemisia coupled with Tamaricaceae and Zygophyllaceae dominated the pollen from the middle of the drill core which indicates a desert vegetation environment occurred during the last glacial.During the phase of 8~7 ka, the UBD is dune-pond environment with steppe vegetation characterized by high percentage of Pinus and Artemisia.