Shifts in bacterial communities drive ecosystem multifunctionality under changed precipitation amount and timing in a semiarid grassland

Precipitation amount and timing profoundlyaffect soil microbial communities and ecosystem functions. However,whether alterations in microbial community and its seasonal dynamics affect soilecosystem multifunctionality (EMF) under changed precipitation in different periods of growing season remain incompletely understood.We conducted a manipulation experiment in a semiarid steppe by simulating a 60% increase and decrease in precipitation during the early (April-June), late (July-September), and entire (April-September) growing seasons to explore the effects of changed precipitation amount and timing on microbial communities, and consequent impacts on EMF in June and September.降水量及其发生时机深刻影响土壤微生物群落与生态系统功能。然而，在生长季不同时期改变降水的条件下，微生物群落及其季节动态变化是否会影响土壤生态系统多功能性（soil ecosystem multifunctionality，EMF），目前仍未得到充分阐明。本研究在半干旱草原开展控制实验，通过模拟生长季早期（4-6月）、晚期（7-9月）及全生长季（4-9月）降水量增减60%的处理，探究降水量与发生时机改变对微生物群落的影响，以及由此对6月和9月土壤生态系统多功能性（EMF）产生的后续效应。