Paludification-driven peatlands development and vegetation variations in Alataw Mountains, Northwest China since the Late Holocene: Insights from multiple indicators

Abstract

Exploring the impacts of environmental changes on the peatlands evolution and vegetation succession can provide valuable insights for studying the development of wetland ecosystems, especially in arid Northwest China. This study conducted analyses of phytoliths, grain size, organic matter, and humification degree in the ARXT peatland within the Alataw Mountains, Xinjiang, and further investigated the formation, development, and vegetation dynamics of the peatland over the past 3100 years by integrating vegetation Rate-of-change (RoCs) analysis and structural equation modeling. The results indicate that the period from 3100 to 2600 cal yr BP was characterized by a shallow lacustrine environment, followed by the gradual onset of paludification and incipient peat accumulation. Between 2600 and 1000 cal yr BP, the system transitioned to a swamp environment, during which peat underwent stable development. Since 1000 cal yr BP, the peatland has been subjected to a generally cold and dry environment, leading to accelerated decomposition of organic matter and unstable peat accumulation. With the onset of lake paludification, herbaceous taxa dominated by Poaceae and Cyperaceae underwent rapid proliferation. Vegetation RoCs increased markedly during the lake paludification phase (3100–2362 cal yr BP), stabilized throughout the peat accumulation period (2362–720 cal yr BP), and rose again after 720 cal yr BP, concomitant with environmental cooling and declining peatland water levels. Driven by the joint influence of temperature and wetland hydrology, paludification emerged as the primary driver of ARXT peatland development and vegetation dynamics. Human pasture activities exerted no significant influence on vegetation changes in ARXT peatland.