Is the response of plant root systems to precipitation primarily driven by the rhizosphere soil?  

作　　者：Yanling Liu Yan Yan Jiuyun Chen Xuyang Lu 

机构地区：[1]Key Laboratory of Mountain Surface Processes and Ecological Regulation,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,No.189 Qunxiannan Street,Tianfu New Area,Chengdu 610299,Sichuan,China [2]University of Chinese Academy of Sciences,No.1 East Yanqi Lake Road,Huairou District,Beijing 101408,China

出　　处：《Ecological Processes》2024年第4期328-345,共18页生态过程(英文)

基　　金：funded by Sichuan Science and Technology Program(2023NSFSC0195).

摘　　要：Background Changes in precipitation alter soil moisture,thereby afecting the aboveground and belowground ecological processes.However,it remains unclear whether plant root systems alter these efects through rhizospheric processes.In this study,a precipitation control experiment was conducted in the alpine grassland of northern Tibet to simulate precipitation changes with a 50%decrease and 50%increase in precipitation.Nutrient and microbial biomass,root traits,and survival strategies in the rhizosphere and bulk soils of the dominant plant,Stipa purpurea,were analyzed for alterations under precipitation changes.Results Increased precipitation(IP)signifcantly decreased the rhizosphere soil total phosphorus and bulk soil ammonium nitrogen and increased the rhizosphere soil total potassium.Decreasing precipitation(DP)signifcantly increased the rhizosphere soil total potassium and decreased the bulk soil total potassium.DP signifcantly reduced microbial biomass carbon,nitrogen and phosphorus in rhizosphere soil,while IP signifcantly increased the bulk soil MBC:MBP,soil C:P imbalance,and soil N:P imbalance.Along the PC1 axis,where the contribution of the traits was relatively large,it was possible to defne the root economic spectrum.The root system of Stipa purpurea from the DP treatment was distributed on the conservative side of the economic spectrum,whereas that from the control and IP treatments were clustered on the acquisition side.Conclusions Increasing and decreasing precipitation mainly afected the contents of total phosphorus and total potassium in rhizosphere soil and the contents of ammonium nitrogen and total potassium in bulk soil of Stipa purpurea.The microbial biomass carbon,nitrogen and phosphorus were mainly afected by a decrease in precipitation.Decreasing precipitation signifcantly reduced microbial biomass carbon,nitrogen and phosphorus,but the rhizosphere MBC:MBN,MBC:MBP and MBN:MBP remained stable under the change of precipitation.Increasing precipitation exacerbated the C:P imbalance and N:P imba

关 键 词：Semi-arid alpine steppe Water variability Soil nutrient MICROORGANISM Rhizosphere and bulk soil Root functional trait 

分 类 号：Q948[生物学—植物学]