A cal. 20-year-resolution pollen record from Gonghai Lake presented the detailed process of mountain vegetation succession and East Asian Summer Monsoon (EASM) changes since the last deglaciation in Shanxi Province, North China. Modern vegetation distribution and lake surface pollen assemblages suggested that the fossil pollen mainly came from local and surrounding vegetation in Gonghai Lake, which reflected the elevational changes of plant communities in study area. From 14,700 to 11,100 cal. yr BP, open forests and mountain meadows dominated by shrubs and herbaceous species in surrounding area, suggesting a weak EASM with less precipitation. In the period between 11,100 and 7300 cal. yr BP, bushwoods and grasses were gradually replaced by mixed broadleaf-conifer forest, first developed by pioneer species of Betula and Populus and then replaced by Picea, Pinus, and Quercus, implying an enhanced EASM and increased temperature and precipitation. During the period of 7300–5000 cal. yr BP, warm-fitted trees became expanded and widespread, indicating a climax community of mixed broadleaf-conifer forest and warm and humid climate with higher temperature and sufficient precipitation and the strongest period of EASM. From 5000 to 1600 cal. yr BP, Pinus pollen increased, but Quercus pollen decreased, showing the breakup of the climax community and the recession of the EASM. Since 1600 cal. yr BP, under the threats of land reclamation and deforestation, forest cover sharply decreased, and mountain grass lands were developed. The EASM changes inferred from pollen record of Gonghai Lake were asynchronous to the oxygen isotope records of stalagmites from southern China. We suggest that the existence of remnant Northern Hemisphere ice sheets and relative low sea levels might hampered the northward penetration of the EASM in early Holocene, which caused the maximum monsoon precipitation to reach northern China until mid-Holocene.

In this paper, we consider the relationship between pollen assemblages, vegetation and climate in some desert and desert-steppe areas in northern China using both surface soil samples and pollen trap samples. Discriminant analysis shows that samples originating from different climatic or geographical regions can be separated reliably on the basis of pollen assemblage regardless of sample type. DCCA analysis indicates that surface soil pollen assemblages show significant correlations with climate parameters. DCCA Axis 1 is negatively correlated with the mean temperature in the warmest month (MT_wa; r = −0.58), whilst axis 2 is positively correlated with mean annual precipitation (P_ann; r = −0.73). Artemisia-to-Chenopodiaceae ratios are generally lower in desert areas than in desert-steppe areas. Pollen productivity relative to Chenopodiaceae ( R_{Chenopodiaceae}) was estimated using least-squares linear regression of pollen influx data against vegetation data and ERV model analysis of percentage pollen data against vegetation data. Rank order of R_{Chenopodiaceae} is consistent regardless of data set or analysis method. Artemisia has R_{Chenopodiaceae} values greater than 3, whilst R_{Chenopodiaceae} Nitraria is around 0.1 and R_{Chenopodiaceae} Poaceae is below 0.1. Our results provide useful information for quantitative reconstructions of paleovegation and paleoclimate in arid or semi-arid Asia.

The northeastern Qinghai‐Tibet Plateau is strongly influenced by the East Asian summer monsoon (EASM), the Indian summer monsoon (ISM) and the westerlies. However, how these various circulation systems interacted in the region during the Holocene, and the nature of the associated environmental impacts, are unclear and even controversial. Here we present a high‐resolution pollen record from Caodalian Lake since 7.9 ka (1 ka = 1,000 cal yr BP), which is used to reconstruct the regional vegetation history and climatic changes. In addition, we use a novel procedure for pollen‐based quantitative paleoclimatic reconstruction to characterize the evolution of precipitation at Caodalian Lake and nearby Qinghai Lake. The results suggest that mean annual precipitation (P_ann) is the most significant factor controlling the fossil pollen record at both sites, and the P_ann reconstructions are well correlated with each other (r = 0.72, p < 0.001). A synthesis of the P_ann records from the two sites indicates that the precipitation in the region began to increase before 10 ka, reached a maximum during 10–5 ka, and gradually decreased thereafter. We propose that the pattern of precipitation evolution in the Qinghai Lake basin resulted from the combined effects of the ISM and EASM, with a precipitation maximum of 10–7 ka for the ISM and 7–5 ka for the EASM; both systems contributed to the regional precipitation maximum during 10–5 ka. Our well‐dated and unambiguous P_ann record also provides the opportunity to reconcile paleoenvironmental reconstructions derived from different paleoenvironmental proxies from the Qinghai Lake basin.