Seasonal patterns of root and shoot interactions in an alpine meadow on the Tibetan Plateau  

作　　者：Minghua Song Qiwu Hu Yuqiang Tian Hua Ouyang 

机构地区：[1]Key Laboratory of Ecosystem Network Observation and Modelling,Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,People’s Republic of China

出　　处：《Journal of Plant Ecology》2012年第2期182-190,共9页植物生态学报（英文版）

基　　金：National Natural Science Foundation of China(grant no.30600070);the National Basic Research program of China(grant no.2005CB422005).

摘　　要：Aims Numerous studies have showed that the balance between negative and positive plant–plant interactions shifted along environmental gradients.But little is known how the positive or negative plant–plant interactions varied with temporal fluctuating habitat conditions and plant ontogenetic phases.Methods In a 2-year experiment,the four perennial grasses(Kobresia humilis,Stipa aliena,Elymus nutans and Saussurea superba)were grown under four interaction treatments(no root or shoot interaction,only shoot interaction,only root interaction,root and shoot interaction).Intensity of above-and belowground interactions is proposed to vary with the fluctuation of seasonal climatic conditions and soil available nutrients.Here we report measurements of above-and belowground interactions during entire growing season.Correlation between plant interaction intensity and seasonal soil available N as well as habitat climate conditions was also performed.Important findings Our experiment found that root interactions had negative effect on plant growth for the four species during growing season.However,both negative and positive shoot interactions occurred among the four species.Despite there being shoot facilitative effect for E.nutans and S.superba,the full interaction was negative,suggested that root interaction take more important role on plant growth than that of shoot interaction.The interaction between root and shoot effect varied as a function of species identity and growth phases.The weak correlation of plant interaction intensity to habitat environmental factors suggested that plant ontogenetic characteristics may be primary factors causing temporal variation in plant interaction.

关 键 词：COMPETITION FACILITATION growing season ontogenetic phase habitat environmental conditions 

分 类 号：Q94[生物学—植物学]