关键词: 留茬高度, 地上生物量, 群落稳定性, 克氏针茅草原

Abstract: According to the vertical distribution of summer birds,Yangtian mountainous district of Qingzhou,Shandong province may be divided into three belts. 51 species of birds are recorded.The species and population of them increase from lower to higher mountainous range. They are closely related with vegetation and influenced by human activities.The birds may be grouped into three types,i.e.,narrow vertical distribution,subvertical distribution and wide vertical distribu-tion. These three types of distribution are both transitional and substitutional,and the former is the major one,The community of birds in each vertical distribution belt is relatively stable. They are more evenly distributed in low mountainous coniferous-deciduous forest.

Key words: stubble height, aboveground biomass, community stability, Stipa krylovii steppe.