Holocene vegetational and climatic variation in westerly-dominated areas of Central Asia inferred from the Sayram Lake in northern Xinjiang, China

Holocene climate and vegetation changes inferred from pollen records of Lake Aibi, northern Xinjiang, China: A potential contribution to understanding of Holocene climate pattern in East-central Asia

“…Furthermore, the moisture variations indicated by the A/C ratio was more or less supported by the pollen based-PCA axis 1 and the ratio of Poaceae pollen percentages to Chneopodiaceae pollen percentages ( Fig. 4; Jiang et al, 2013).…”

“…The ratio of the Artemisa pollen percentage to the Chenopodiaceae pollen percentage (A/C) was based on the observation that the percentage of Chenopodiaceae increases with increasing aridity at the expense of the percentage of Artemisia (El- Mosilimany, 1990;Luo et al, 2009;Zhao et al, 2012), and the ratio was widely used in arid and semiarid areas to semi-quantitatively estimate the aridity or moisture level. The A/C ratio was used as proxy of moisture conditions in the following sequences: Lake Sayram (Jiang et al, 2013), Lake Bosten (Huang, 2006;Huang et al, 2009) and Lake Balikun (Tao et al, 2010). However, the A/C ratio is not valid in the lower parts (i.e., swamp conditions) of the Lake Wulungu (Jiang et al, 2007;Liu et al, 2008) and Lake Aibi cores, in which fluvial or/and eolian environments undermined the validity of the ratio as a semiquantitative proxy for moisture.…”

“…Later studies lent support to the proposition that the Holocene climate change in Xinjiang was typified by warmdry and cool-wet modes, the westerlies type (Huang, 2006Chen et al, 2008;Tao et al, 2010;An et al, 2011). A third proposition stated that the Holocene climate change in Xinjiang was influenced both by the Asian monsoon and the westerlies (Jiang et al, 2007(Jiang et al, , 2013Liu et al, 2008).…”

“…During the past two decades, many sequences of Holocene climate change were reconstructed in Xinjiang, including Lake Bosten (Wünemann et al, 2003Huang, 2006Mischke and Wünemann, 2006) in southern Xinjiang, Lake Manas (Sun et al, 1994;Rhodes et al, 1996), Lake Wulungu (Jiang et al, 2007;Liu et al, 2008), Lake Aibi (Li, 1993;Wu et al, 2005;Tudryn et al, 2010), Lake Sayram (Jiang et al, 2013) in northern Xinjiang, Lake Balikun (Han and Dong, 1990;Xue et al, 2008;Tao et al, 2010;Xue and Zhong, 2011;Zhong et al, 2011;An et al, 2012) and Lake Tuolekule in eastern Xinjiang. In addition, an eolian section (Yili Section) Zhao et al, 2013) and a stalagmite sequence (Kesang Cave) (Chen et al, 2012) in Yili Valley of western Xinjiang also contain detailed reconstructions of Holocene climate change.…”

Pollen-inferred Holocene vegetation and climate histories in Taro Co, southwestern Tibetan Plateau

“…Multiple environmental proxies of the Wulungu Lake record indicated a warm and dry condition during 10,000-7,000 cal a BP [46]. At Symram Lake, vegetation was typical desert steppe/steppe, and the climate was warm and dry at 9,600-5,500 cal a BP [47]. Dry conditions in the early Holocene were inferred from the Bosten Lake pollen record [48].…”