Effects of elevated CO2 and N addition on growth and N2 fixation of a legume subshrub (Caragana microphylla Lam.) in temperate grassland in China.

ABSTRACT: It is well demonstrated that the responses of plants to elevated atmospheric CO(2) concentration are species-specific and dependent on environmental conditions. We investigated the responses of a subshrub legume species, Caragana microphylla Lam., to elevated CO(2) and nitrogen (N) addition using open-top chambers in a semiarid temperate grassland in northern China for three years. Measured variables include leaf photosynthetic rate, shoot biomass, root biomass, symbiotic nitrogenase activity, and leaf N content. Symbiotic nitrogenase activity was determined by the C(2)H(2) reduction method. Elevated CO(2) enhanced photosynthesis and shoot biomass by 83% and 25%, respectively, and the enhancement of shoot biomass was significant only at a high N concentration. In addition, the photosynthet

SUBMITTER: Zhang L 

PROVIDER: S-EPMC3202592 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature