Dwarf bamboos often negatively affect tree recruitment,survival,and growth,leading to arrested tree regeneration in forested habitats,and often regarded as an ecological filter for forest regeneration.Studies so far have focused on the effects of dwarf bamboos on the performance of seedlings and saplings,but the influence of dwarf bamboos on forest dynamics may start very early in the forest regeneration process by altering seed rain patterns.In a field experiment we manipulated the density of Fargesia decurvata,a dwarf bamboo native from the understory of subtropical mountain forests in southwest China,to test the prediction that high density bamboo groves have an ecological filter on the density and composition of seed rain,the most dense dwarf bamboo groves have a higher seed limitation,compared to the others density bamboo groves and without bamboo stands.