In arid central Asia, the geo-ecological environment of the well-vegetated high mountains differs from that of the extensive arid Gobi desert areas, with the forested areas having experienced a different pattern of humidity variations compared to the dryland regions. Therefore, the moisture history of the forest areas reconstructed by tree rings may differ from that of the dryland areas. In the extremely arid area of the western Qilian Mountains and the surrounding dryland areas, where forest is absent, it is unclear how humidity conditions have changed over the past several centuries. Here, we use a pollen record from Tian’E Lake, with a chronology based on ²¹⁰Pb and ¹³⁷Cs, and with an average temporal resolution of ∼2 years, to reconstruct the humidity changes over the past 300 years. The results show that the pollen assemblage is dominated by Artemisia and Amaranthaceae (=Chenopodiaceae), and therefore, the A/C (Artemisia/Chenopodiaceae) ratio can be used to reconstruct changes in humidity conditions. Based on the pollen A/C ratio, two relatively wet periods are identified: ∼1740–1750 and 1840–1980, and two dry intervals: ∼1750–1840 and 1980–2018. This pattern of variation is similar to that reconstructed from nearby humidity records based on tree-ring width adjacent to the Tian’E Lake area and with instrumental records from meteorological stations over the past several decades. However, there are significantly different records between pollen-based and tree-ring based humidity during ∼1760–1830, 1880–1910, and 1920–2018 in the Qilian Mountains on long timescales. We conclude that pollen-based humidity records from dryland areas may differ from those reconstructed from tree-ring widths in forested mountain areas, especially when the temperature was increasing. It was further suggested that there was an antiphased relationship in humidity conditions between westerlies-dominated central Asia and monsoon areas over the past century.

在干旱的中亚，植被茂盛的高山的地质生态环境与干旱的戈壁沙漠地区的地质生态环境不同，与干旱地区相比，森林地区的湿度变化模式不同。因此，由树环重建的森林地区的水分历史可能与干旱地区的水分历史不同。在祁连山西部极度干旱的地区以及周围没有森林的干旱地区，目前尚不清楚过去几个世纪中湿度的变化情况。在这里，我们使用来自天'湖的花粉记录，以²¹⁰ Pb和¹³⁷的年表为基础Cs，平均时间分辨率约为2年，以重建过去300年的湿度变化。结果表明，花粉组合主要由蒿 和A菜科（=藜科），因此，A / C（蒿/藜科）比率可用于重建湿度条件的变化。根据花粉的A / C比，确定了两个相对潮湿的时期：〜1740–1750和1840–1980，两个干燥间隔：〜1750–1840和1980–2018。这种变化模式类似于根据过去几十年中与天'湖地区相邻的年轮宽度从附近的湿度记录重建的数据以及从气象站获得的仪器记录的变化模式。但是，在祁连山的1760年至1830年，1880年至1910年和1920年至2018年期间，基于花粉的湿度和基于树木年轮的湿度之间存在长远的差异。我们得出的结论是，干旱地区基于花粉的湿度记录可能与森林山区的树木年轮宽度所重建的湿度记录有所不同，尤其是在温度升高时。