Abstract: In order to understand the effect of grazing intensity on the seed production of Caragana pygmaea,the flower and fruit characteristics of C.pygmaea under different grazing intensities in Inner Mongolia,China were measured,which included the phonological period of sexual reproduction of C.pygmaea,flower number,flower biomass,coefficient of flower variation,sexual reproduction input of flower,pod number,total seed number,etc.Results showed that grazing treatments did not affect significantly the phonological period of sexual reproduction of C.pygmaea; grazing reduced significantly the flower number,flower weight and sexual reproduction input of flower,but it did not influence the coefficient of flower variation significantly.Besides,grazing reduced significantly the number of young pods and the seed number in pods,thus the total seed number of C.pygmaea was decreased.These results indicated that grazing could significantly reduce the seed production of C.pygmaea.In addition,the abortive rate of florescence was the highest under heavy grazing,which indicated that the life stage from florescence to young pods was a bottleneck for seed production of C.pygmaea.Therefore,the grazing intensity during florescence of C.pygmaea should be appropriately decrease.

Key words: grazing, Caragana pygmaea, flower, fruit, seed production