Acta Geographica Sinica ›› 2023, Vol. 78 ›› Issue (11): 2781-2796.doi: 10.11821/dlxb202311009

• Surface Process • Previous Articles     Next Articles

Spatial distributions of topsoil DNA concentrations and their impact factors in the Buha River catchment, Qinghai Lake

ZHOU Kehan1,2(), WANG Xiaqing2(), LIU Fenggui1, ZHOU Qiang1, WAN Dejun3, LYU Feiya2, HUANG Ping'an2   

  1. 1. School of Geographic Science, Qinghai Normal University, Xining 810016, China
    2. College of Geography and Tourism, Hunan University of Arts and Science, Changde 415000, Hunan, China
    3. School of Geographical Science, Nantong University, Nantong 226019, Jiangsu, China
  • Received:2023-01-17 Revised:2023-10-16 Online:2023-11-25 Published:2023-11-29
  • Contact: WANG Xiaqing E-mail:charlottezhou256@163.com;wangxq@huas.edu.cn
  • Supported by:
    National Natural Science Foundation of China(42167062);National Natural Science Foundation of China(42207511);The Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0603);Natural Science Foundation of Qianhai Province(2022-ZJ-920);PhD Research Startup Foundation of Hunan University of Arts and Science(21BSQD33);Fund of Geography Subject([2022]351)

Abstract:

Sedimentary DNA has been widely used in the studies of climate change, ecological function, and environmental archaeology, because it can provide biological dynamic information with temporal dimension in geographical environment. However, the surface processes and impact factors of sedimentary DNA within the catchments are still not fully understood, which limits the accuracy of sedimentary DNA data interpretation. In this study, topsoil DNA concentrations at the Buha River catchment in northwest Qinghai Lake, which was suitable for DNA preservation, were firstly measured based on domestic new sedimentary DNA laboratory. Meanwhile, soil physical and chemical compositions, including grain size, elements, loss on ignition and TOC, were determined. Subsequently, the abiotic factors which had impact on spatial distribution of topsoil DNA concentration were analyzed by combing the status related with climate, vegetation cover, and land use at the Buha River catchment. The results showed that the average concentration of topsoil DNA at the whole catchment was 0.91 μg/g, with the higher values in the middle reaches of the Buha River and its tributary Jilmon River, while the lower ones in the lower reaches near the Qinghai Lake. In addition, topsoil DNA concentrations at the catchment were positively correlated with the contents of clay and organic matter, but negatively correlated with sand content and the intensity of weathering and leaching. Besides, high vegetation cover and frequent grazing activities contributed to the enrichment of the topsoil DNA, while strong weathering and leaching under warm and wet environment, river transportation and crop cultivation reduced the concentration of the topsoil DNA. All the above results provide a scientific basis for an understanding of the deposition processes of sedimentary DNA and their impact factors in the Buha River catchment, which are helpful for revealing sedimentary DNA compositions and evolution processes of ecological environment and human-environment relationship in regions west of the Qinghai Lake.

Key words: sedimentary DNA, nucleic acid concentration, impact factors, Buha River catchment, Qinghai Lake