Effects Of Simulated Warming And Nitrogen Application On The Quantity Characteristic Of Leymus Chinensis Population

Global warming and nitrogen deposition are the crucial problems that people face nowadays. We used infrared ray heat instrument to simulate the effects of global warming and nitrogen deposition on the Population of Leymus chinensis Grassland.This study indicated that the effects of nitrogen on height and density of L. chinensis community were significant. L. chinensis becomes increasingly important. At the same time, higher temperature could be advantageous condition on enhancement of the importance value of L. chinensis in the period of sufficient rainfall. We summarized that nitrogen with rainfall and temperature with rainfall had cooperative effects on the importance value of L. chinensis.In all observational period, the effects of nitrogen on aboveground biomass of L. chinensis population was significant. The effects of warming on underground biomass of L. chinensis population was significant. But at the time of higher temperature, the effect of warming would decrease, and the effect of nitrogen would be increasingly important.The phenophase marks of L. chinensis increased with the treatment of warming and nitrogen increased from 21 May to 17, June. But it decreased from 24, June to 10, August. It means that phenophase of L. chinensis delayed in this period. At the same time, nitrogen and temperature had no cooperative effects on the phenophase of L. chinensis.