中文摘要：

以内蒙古锡林郭勒草原羊草草原群落18年的动态监测数据及降水量数据为基础,在对草原植物进行能量功能群划分的基础上,分析了年降水量、生长季降水量（5-8月）对草原群落生物量、能量功能群组成的影响。结果表明：群落生物量构成中高能群所占比例最大;低能群最小,群落生物量的年际波动与高、中能群生物量变动趋势一致,而与低能群不相关;群落生物量和高能群生物量均与年降水量显著相关;中、低能群生物量则没有受到年降水量的显著影响。研究结果可为进一步揭示全球变化背景下,干旱半干旱区草原植物群落的动态变化规律,特别是群落能量变化规律提供有效参考。

英文摘要：

Based on 18 years of dynamic monitoring data of Leymus chinensis steppe community in Xilingol Grassland and precipitation data,and grouping grassland plants into energy functional groups,the effects of the annual precipitation,growth season precipitation（ May to August） to community aboveground biomass and energy functional group composition were analyzed in this study. The results showed that： the biomass proportion of high- energy group plants was the highest in community composition,low- energy group plants was the lowest,interannual fluctuation of the community biomass followed the same trends as those of high- energy group and medium- energy group,and not related with low- energy groups. The biomass of the community and high- energy group were significantly correlated with the annual precipitation. Middle and low energy groups were not significant correlated with the annual precipitation. The results can provide an effective reference to further reveal the dynamic changes of grassland plant communi-ties,especially the energy change law of community,in arid and semi arid regions in the context of global change.