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青藏高原中部的草甸/草原混合生态群落,对气候变化非常敏感.孢粉记录显示草原发育时期,莎草减少,区域气候是相对干旱的,在时间上对应季风相对弱的时期.依据唐古拉山垭口湖、阿洪错和错那3个淡水湖泊钻孔孢粉分析,定量重建的温度和降水指标,探讨该地区8200 cal a BP以来的植被与气候变化.8200～6500 cal a BP,尤其是8200～7200 cal a BP,植被以草甸/草原混合生态群落为主,显示强季风控制着青藏高原中部;6000～4900,4400～3900以及2800～2400 cal a BP时期区域植被以草原植被为主,应是3次百年尺度的干旱事件;4900～4400 cal a BP期间植被类型由草原向草甸转变;6500～5400和3000～1600 cal a BP出现两次大的变干事件;数值摸拟估计,高原中部接近于现今的环境,最早可能出现在6500cal a BP,自3000cal a BP以后高原中部季风性降水和湿度逐渐减少至现今水平,可能在700～300cal a BP出现一次小冰期变冷事件.
The mixed ecological community of meadow / steppe in the middle of the Qinghai-Tibet Plateau is very sensitive to climate change.The records of sporopollen showed that during the development of grassland, the sedge decreased and the regional climate was relatively arid, corresponding to the time when the monsoon was relatively weak.According to the Tanggula The analysis of sporopollen in the three freshwater lakes in Yakou Lake, Ahong and Helena, and the temperature and precipitation indices of quantitative reconstruction, discusses the vegetation and climate change since the 8200 cal a BP in the area, ranging from 8200 to 6500 cal a BP, especially 8200 ~ 7200 cal a BP. The vegetation was dominated by meadow / grassland mixed ecological communities, which indicated that strong monsoon controlled the central Tibetan Plateau. The regional vegetation in the period of 6000 ~ 4900, 4400 ~ 3900 and 2800 ~ 2400 cal BP was dominated by grassland vegetation , And should be three hundred-year-scale drought events. During the period from 4900 to 4400 cal a BP, the vegetation types changed from grassland to meadow. Two large desiccation events occurred between 6500 and 5400 and 3000 and 1600 cal a BP. Numerical simulation . The central part of the plateau is close to today’s environment, with the earliest possible occurrence at 6500 cal a BP. Since 3000 cal a BP, monsoon precipitation and humidity in the central part of the plateau have gradually decreased to the present level, possibly with a small ice at 700-300 cal BP Cold events.