Nitrogen perturbation on herbaceous vegetaion

Nitrogen is a key element controlling the species composition, diversity, dynamics and function of many terrestrial, freshwater, and marine ecosystem. Agricultural, combustion of fossil fuel and other human activities have alter the global cycle of nitrogen substantially, generally increasing both availability and mobility of nitrogen over large region of earth. Human are altering the global cycle of nitrogen via combustion of fossil fuel, production of nitrogen fertilizers, cultivation of nitrogen fixing legumes and other actions.To asses' nitrogen deposition effects on biodiversity, it is important to consider not only effect on species richness but also effect on functional richness. Nitrogen is one of the 17th chemical element required for plant growth and reproduction, it is used by the living organisms to produce a number of complex organic molecules like amino acid, protein and nucleic acid. The effect of nitrogen disturbance of herbaceous vegetation is more prominent because most of the herbaceous communities are adapted to low nutrient condition, any increase in nutrient input, especially nitrogen is very likely to cause pronounced changes in community structure.