Abstract: Dynamics of Leymus chlviensis steppe community primary production were studied in southern Xilinguole Steppe region during eleven years from 1983 to 1993.Results showed that fluctuations of the community above-ground biomass were remarkable.During eleven years there were three bumper harvest years,seven average years, and one shortfall year.Seasonal increasing curves of the community above - ground biomass conformed to Compertz curves, B_t = B_max·e^-ea-kt.The peakvalues came 125.2 to 162.7 days after herbage turnning green.The main factor that affects fluctuations of the cornmunity above-ground biomass is precipitation.Mathematical models of the relationship between the community above-ground biomass and the accumulated precipitation and cumulative temperature were founded- Some rational suggestions on animal production according to the comrnunity primary production were put forward.

Key words: Leymus chinensis steppe, Community, Above-ground biomass, Precipitation

摘要： 在锡林郭勒盟南部羊草草原对群落初级生产力动态进行11年的定位研究,结果表明:群落地上生物量有着显著的波动,在11年中遇丰年3个、平年7个、欠年1个。群落地上生物量季节积累动态符合Compertz曲线B_t＝B_max·e^-ea-kt,其高峰值出现在返青后的125.2～162.7天。制约群落地上生物量波动的限制因素是水分条件。建立了群落地上生物量与水热因子关系的数学模型。根据这些规律作者对畜牧业生产提出了合理建议。

关键词: 羊草草原, 群落, 地上生物量, 降水量