Variation in carbon,nitrogen and phosphorus partitioning between above-and belowground biomass along a precipitation gradient at Tibetan Plateau

作     者：HONG Jiang-tao WANG Xiao-dan WU Jian-bo 

作者机构：Institute of Mountain Hazards and EnvironmentAcademy of Sciences of SciencesChengdu 610041China University of Chinese Academy of SciencesBeijing 100049China 

出 版 物：《Journal of Mountain Science》 (山地科学学报（英文）)

年 卷 期：2016年第13卷第4期

页      面：661-671页

核心收录：

学科分类：090503[农学-草业科学] 0909[农学-草学] 07[理学] 0905[农学-畜牧学] 09[农学] 0903[农学-农业资源与环境] 0713[理学-生态学] 

基　　金：supported by the Western Action Plan Project of the Chinese Academy of Sciences(Grant No.KZCX2-XB3-08) the Strategic Pilot Science and Technology Projects of the Chinese Academy of Sciences(Grant No.XDB03030505) the National Key Technology Research and Design Program of China(Grant No.2010BAE00739-03) 

主　　题：Biomass allocation Nutrient concentration Qinghai Tibetan Plateau Alpine steppe Stipa purpurea 

摘      要：Precipitation is a potential factor that significantly affects plant nutrient pools by influencing biomass sizes and nutrient concentrations. However, few studies have explicitly dissected carbon(C), nitrogen(N) and phosphorus(P) pools between above- and belowground biomass at the community level along a precipitation gradient. We conducted a transect(approx. 1300 km long) study of Stipa purpurea community in alpine steppe on the Tibet Plateau of China to test the variation of N pool of aboveground biomass/N pool of belowground biomass(AB/BB N) and P pool of aboveground biomass/P pool of belowground biomass(AB/BB P) along a precipitation gradient. The proportion of aboveground biomass decreased significantly from mesic to drier sites. Along the belt transect, the plant N concentration was relatively stable; thus, AB/BB N increased with moisture due to the major influences by above- and belowground biomass allocation. However, P concentration of aboveground biomass decreased significantly with increasing precipitation and AB/BB P did not vary with aridity because of the offset effect of the P concentration and biomass allocation. Precipitation gradients do decouple the N and P pool of a S. purpurea community along a precipitation gradient in alpine steppe. The decreasing of N:P in aboveground biomass in drier regions may indicate much stronger N limitation in more arid area.