内蒙古两个不同温度型草原站点植物科属组成及生态类群对比

在内蒙古草原区选择暖温型（阿贵庙）和中温型（黑山头）两个草原站点对基植物的科属组成，区系地理成份，生活型，水分生态类群和C3／C4光合功能群进行对比，植物的科属组成反映出物种多样性随续上度增加而减少的趋势，科属的相似性较大反映出半干旱草原区植被科属组成的共性，而物种组成的相似性较小则反映了两站点植物随温度及水热组成状况的差异呈出现地理替代与区域分异的特征，水分生态类群比较较为接近，反映出半干旱气体的共同作用。但C3／C4光合功能群比较差异较大，反映出C4植物随纬 度增加，气温降低而减少的趋势。

Comparison on Species Composition and Ecological Groups in Two Stations of Different Thermometric Types

In two stations of Warmth-temperature Steppe (Arguimiao Temple) and Moderate-temperature Steppe (Heishantou) ,the contrast research has been carried out on species composition, floristic composition, life type spectrum, water ecological groups and C3/C4 photosynthetic-functional group. Plant species composition shows that the species diversity decrease along with increase of the latitude. The result of similarity comparison demonstrates that families and genus in the stations is more similar respectively and the species is more discrepant .Larger similarity in the families and genus reflects that the general character of the vegetation in semi-arid steppe region, but smaller similarity in species composition indicates the characteristics of geographic replacement and regional differentiation in virtue of difference in temperature and combination of water and heat of the two stations. The water ecological types proportion is very close, reflecting the mutual influences on the two stations in the semi-arid steppe region. However, the proportion of C3/C4 photosynthetic functional groups is very disperity of them. There are only 5 species of C4 plant (4.2%) and the ratio of C3/C4 plant equal to 22.4∶1 in Moderate-temperature Steppe station and 22 species of C4 plant (10.95%) and the ratio of C3/C4 plant equal to 8.136∶1, shows the tendency of C4 plants′ quantity and proportion decreases along with increasing of latitude and decrease of atmospheric temperature.