Response of Soil pH to Precipitation Alterations across Chinese Grassland:A Meta-Analysis
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°C.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%,respec-tively.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 pro-vide a scientific basis for managing soil nutrients in grassland ecosystems in arid and semi-arid regions in the con-text of global precipitation pattern changes.
万方数据
维普
