How human beings adapt to the extreme environment on the Tibetan plateau (TP) has been a major scientific issue of concern to scientists. Here, fecal stanols in the Xiada Co sediment core on the western TP were used to reconstruct local human and ruminant populations over the past 4700 years. Climate data based on brGDGTs and XRF data in the same sediment core, along with archaeological evidence from the TP, were compiled to investigate the relationship between human and nature. Our analysis suggests that the change in human and ruminant populations in the Xiada Co basin was likely influenced by regional climate change, lake level, and social factors. From 4700 to 2900 cal yr BP, the populations were relatively high due to the warm and humid climate. During 3400–2900 cal yr BP, the basin experienced the highest population density. This could be attributed to the combination of a relatively warm and humid climate, the introduction of cold and dry-tolerant crops like barley, and the introduction of livestock such as sheep and cattle. Between 2900 and 2450 cal yr BP, the increased lake levels and frequent level changes likely caused significant population declines. From ~1000 to 300 cal yr BP, temperature appeared to have a stronger influence on human and ruminant population change compared. Notably, around 300 cal yr BP, the basin experienced the smallest human and ruminant populations due to the extremely cold and dry climate, as well as frequent conflicts between Guge and Ladakh. Furthermore, the significant rise in the levels of ruminant fecal stanols suggests a shift in the primary domesticated ruminant species after ~1250 cal yr BP, with sheep/goat becoming the dominant livestock. This study confirms the use of fecal stanols as a valuable tool for reconstructing ancient human activities on the western TP.
 

Tibetan Plateau; Fecal stanols; Human population; Climate change