Response Of Typical Steppe Vegetation Of Using Manners To Climate Factors In Inner Mongolia

The research was carried out three experiment sites that grazing land，mowing land，enclosed land（enclosed since1996）on the typical steppe of taipusi Inner Mongolia and the landform，physiognomy，original vegetation was consistent.The tendency of climate change， incluing temperature andprecipitation，was analyzed based on the climate date from1979to2009. Grassland productivity wascompared and analyzed based on3different models（Miami model，Thornthwaite Memorial model，Zhou Guang-sheng model）. The objective of the experiment is to research the effects fhe temperatureand precipitation in different periods affected vegetation composition，net primary productivity，speciesdiversity and probe into rational use and scientific management in order to promote the sustainabledevelopment of grassland agriculture.The main results are as follows：1．The annual mean temperature of Taipusi banner increased significantly by0.62℃/10a from1979to2009. In addition，seasonal temperature tended to rise clearly，among of which wintertemperature increased most significantly by0.84℃/10a. But annual precipitation and annualevaporation has decreased5.3mm/10a and72.7mm/10a. Zhou Guang-sheng model has higher precisioncalculating grassland productivity than other models in this paper.2．Species richness of enclosed land varied with the variation of precipitation obviously and variedfrom16to23species. Species richness was higher in wet years and varied from20to23species andlower in dry years and varied from16to18species. Species richness of mowing land varied with thevariation of precipitation obviously and varied from19to25species. Species richness was higher inwet years and varied from21to25species and19species in the dryest year. Species richness of grazingland varied with the variation of temperature obviously and varied from17to23species. The number ofspecies were23species in the coldest year and17species in the hottest year.3．There were remarkable positive correlations between net primary productivity of life-formfunctional groups and community and temperature in July of enclosed land，mowing land and grazingland（P0.05）. The effects that precipitation and precipitation distribution yearly affected the netprimary productivity of life-form functional groups and community were significant. In particular, thegrassland net primary productivity was obviously affected by the precipitation in growth season.4． There were negative correlations of enclosed land and mowing land between Margalef index,Shannon-Weaver index, Pielou index and annual mean temperature；positive correlations betweenMargalef index, Shannon-Weaver index, Pielou index and precipitation in different periods；negativecorrelations between Margalef index, Shannon-Weaver index, Pielou index and aridity index. There waspositive correlation of enclosed land and mowing land between Simpson index and annual meantemperature；negative correlation between Simpson index and precipitation in different periods；positivecorrelation between Simpson index and aridity index. The correlations between Margalef index,Shannon-Weaver index, Pielou index, Simpson index and climate factors of grazing land were small.5．In different using manners，the effects of climate factors on typical steppe vegetation in Inner Mongolia were in general accord. That is，the using manners can’t change the effects of climate factorson typical steppe vegetation with limits. But overgrazing is the main reason of grassland degradation，the cliamte may accelerate the process.