Abstract: Changes in rainfall distribution and the increasing frequency of extreme precipitation events are key characteristics of global climate change. This study aims to explore the effects of these rainfall variations on soil pH levels in grassland ecosystems across China. A comprehensive analysis was conducted on 159 studies that investigated the effects of increased and decreased precipitation on soil pH in Chinese grassland ecosystems. The study integrates these findings to examine how soil pH responds to precipitation manipulation and identifies the key influencing factors. Increased precipitation led to significant rises in soil pH, with increases of 0.9% and 2.3% in regions receiving less than 200 mm and between 200-400 mm of annual rainfall, respectively, and by 6.7% in areas with an average annual temperature below 0℃. Additionally, soil pH increased by 4.1%, 4.9%, and 1.3% in weakly acidic, neutral, and weakly alkaline grasslands, respectively, but decreased by 2.7% in alkaline grasslands. In typical and desert grasslands, soil pH increased by 1.8% and 0.9%, respectively. In contrast, reduced precipitation decreased soil pH by 0.4% and 0.7% in areas with annual rainfall below 200 mm and between 200~400 mm, respectively. Furthermore, soil pH declined by 0.7% in weakly alkaline grasslands, by 1.5% in meadow grasslands, but increased by 0.9% in typical grasslands.Increased precipitation notably raised soil pH by enhancing vegetation cover, reducing species richness and below-ground biomass, and indirectly altering soil carbon （C） and nitrogen （N） content. Conversely, reduced precipitation significantly lowered soil pH, mainly by affecting soil C, N, and phosphorus （P） content. These findings provide a scientific basis for managing soil nutrients in grassland ecosystems in arid and semi-arid regions in the context of global precipitation pattern changes.

Key words: Extreme precipitation, Precipitation decrease treatments, Nutrient management, Precipitation increase treatments

摘要： 降雨分配的变化以及极端降雨事件的频发是全球气候变化的重要特征,为了探究降雨变化对中国草地土壤pH值的影响,本文通过检索159篇关于增雨和减雨处理对中国草地生态系统土壤pH值影响的文章,运用整合分析,探究了土壤pH值对增雨和减雨处理的响应及其影响因素。结果表明：增雨处理在年降雨小于200 mm和200~400 mm地区土壤pH值提高0.9%和2.3%,年均温低于0℃地区土壤pH值提高6.7%；弱酸性、中性、弱碱性草地上土壤pH值提高4.1%,4.9%和1.3%,碱性草地降低2.7%；典型、荒漠草原上土壤pH值提高1.8%和0.9%。减雨处理在年降雨量低于200 mm和200~400 mm地区土壤pH值降低0.4%和0.7%；弱碱性草地土壤pH值降低0.7%,草甸草原土壤pH值降低1.5%,典型草原土壤pH值提高0.9%。增雨处理通过增加植被盖度,减少物种丰富度和地下生物量,提高草地土壤pH值；减雨处理通过对土壤碳氮磷含量的影响降低草地土壤pH值。本研究结果可为全球降雨格局变化背景下草地土壤养分管理提供科学依据。

关键词: 极端降雨, 减雨处理, 养分管理, 增雨处理