Effect of Climate Change on the Stipa krylovii Grassland Vegetation of Hulun Buir

In order to understand the effect of climate change on Stipa krylovii grassland vegetation and its characteristics,the temperature and vegetation of Hulun Buir Stipa krylovii grassland in Argun River Basin during 2002-2006 were investigated and analyzed.Results showed that the average temperature of this area had a fluctuating decline with the advance of time.The important value of Stipa krylovii,Leymus chinensis,Suaeda glauca,Potentilla bifurca decreased with the yearly decrease of winter maximum temperature,whereas that of Cleistogenes aquarrosa increased.The plant height,cluster number,coverage and important value of Cleistogenes aquarrosa had negative correlations with winter maximum temperature significantly.The effect of precipitation on predominant species was not obvious.There was no significant relationship between winter maximum temperature and diversity indices(Simpson index and Shannon-Wiener index) and evenness index.Therefore,there was no significant impact on the structure and function of Stipa krylovii grassland community during these five years,although a few plants were sensitive to the change of winter maximum temperature.