关键词: 短花针茅草原, 植物区系, 种子植物, 内蒙古

Abstract: The flora characteristics of Stipa breviflora steppe in Inner Mongolia at different levels of family, genera and species were studied. ①The total of 161 species, belongs to 31 families and 96 genera of Spermatophyte, was counted. Most of them concentrated on several main families, which demonstrated floristic dominances obviously; ②The ratio of genera to species, 1/1.68, of the steppe was smaller than that of Inner Mongolia, China and of the world, represented the low level differentiation of species; ③The flora showed the composition of temperate zone remarkably, although there was a certain relationship with the flora of tropic zone. The transitional characteristics of the flora was clear; ④The flora was dominated by young components, while ancient ones played a companionate role; ⑤According to the statistics of life forms, perennial herbs dominated the steppe, which showed the features of plant species composition of steppe communities. However, there were a lot of shrubs and semi-shrubs due to the sandy soil covered many areas in this region; ⑥Compared with non-xerophytes that accounted for a large proportion, the xerophytes were still dominances. The transition in terms of ecological types of water was obvious, too; ⑦This steppe is fragile at present. It is necessary to strengthen the protection and to promote the rational utilization so as to implement sustainable development.

Key words: Stipa breviflora steppe, flora, Spermatophyte, Inner Mongolia