Abstract: With the application of nitrogen fertilizer(urea 112.5kg.ha^-1), the aboveground biomass of community increases 66.15％ as an average of 5 years. The aboveground biomass of Aneurolepidium chinense, Stipa grandis and Salsola collina increases 71.34％, 44.86％ and 269.44％ respectively. The density of community increases 63 plants.m^-2. The density, height and individual plant weight increase 90 shoots.m^-2, 8.48cm and 0.0275g respectively. Grasses and Chenopodiaceae Plants are more susceptible to the application of nitrogen fertilizer.

Key words: Sagitta crassa, temperature, salinity, oxygen consumption rate, specific oxygen consumption rate, asphyxiation point