Abstract：
The Tibetan Plateau (TP) is one of the most challenging areas for human long-term settlement due to its extreme living environment. Understanding the relationship between human activities and environmental changes in this extreme environment is important and can provide a historical reference for adapting to future climate change. In this study, we took the Angren Basin in the southern TP as a case study to elucidate the relationship since Little Ice Age (LIA). Using fecal stanol in feces, lake and river surface sediments, surface soils, and sediment core, we found that specific indices S1 and S2 from the composition of coprostanol, epicoprostanol, 5β-ethylcoprostanol and 5β-ethylepicoprostanol can reflect changes in human population and herbivores, respectively. Through the comparison between environmental changes determined by grain size, elements, sedimentation rate, and other climate records, the relationship between human activities and environmental changes was interpreted. Our results indicate that: (i) during 1480-1820 CE, the fecal stanols in lake sediments mainly originated from livestock, and the human population was low. In contrast, during 1820-2021 CE, the proportion and flux of S1 have been continuously increasing, indicating significant population growth. (ii) During the middle LIA, the cold-dry climate inhibited the development of agriculture and farming. However, the increased precipitation during the late LIA promoted that development, resulting in an increase in human population and livestock in a short term. (iii) Since 1951, people have reclaimed wasteland and developed husbandry, leading to increased soil erosion. (iv) Over the past 40 years, with a warm-humid climate and good policy support, human activities, such as agriculture and husbandry, have rapidly increased, but soil erosion has declined in the recent 20 years due to good soil-water conservation efforts. This study sheds light on the relationship between human activities and environmental changes and provides insights into future climate change responses.
摘要：
青藏高原（TP）由于其极端的居住环境，是人类长期定居最具挑战性的地区之一。了解这种极端环境中人类活动与环境变化的关系具有重要意义，可以为适应未来气候变化提供历史参考。在这项研究中,我们以TP南部的安格伦盆地为例，阐明了自小冰河时代（LIA）以来的关系。在粪便中使用粪便甾烷醇，湖泊和河流表面沉积物，表层土壤，和沉积物核心，我们发现，具体指标S1和S2的成分，表前列腺素,5β-乙基前列腺素和5β-乙基吡啶前列腺素可以反映人口和草食动物的变化，分别。通过比较由晶粒尺寸决定的环境变化，元素,沉降速率,和其他气候记录，解释了人类活动与环境变化之间的关系。我们的结果表明：(I)公元1480-1820年，湖泊沉积物中的粪便甾烷主要来自牲畜，人口很少。相比之下,在1820-2021年的CE，S1的比例和通量一直在不断增加，表明人口显著增长。(ii)在LIA中间，寒冷干燥的气候抑制了农业和农业的发展。然而,LIA后期降水的增加促进了这种发展，导致人口和牲畜在短期内增加。(三)1951年以来,人们开荒,发展畜牧业,导致土壤侵蚀增加。（四）过去40年，在温暖潮湿的气候和良好的政策支持下，人类活动,如农业和畜牧业，迅速增加，但是由于良好的水土保持努力，土壤侵蚀在最近20年有所下降。这项研究揭示了人类活动与环境变化之间的关系，并为未来的气候变化响应提供了见解。
