Abstract:

en vegetation transects were surveyed along the QinghaiTibet Railway between Xidatan and northern slopes of Tanggula Range on Tibet Plateau.The trends of species richness and vegetation coverage along the latitude were analyzed.Besides,the relationship between the species richness and coverage was analyzed.In the high altitude region of Tibet Plateau,just as other low altitude region,the species richness gradually rose from the northern latitude to southern latitude of the study area.The coverage of plots rose in the same condition.The species number was 5 or 6 in the northern transects,but it was 9 or 10 in the southern transects.The altitude of the study area was 4 400~4 900 m,so high altitude and the altitude difference between transects did not influence the change rule of species richness.Transects were arranged beside the railway,so the topography was gentle,belong to piedmont,plain or valley.All transects located on the gentle topography reduced the influence of altitude and topography on species richness.So it was propitious to sum up the influence of latitude on the species richness.The vegetation coverage gradually rose as the latitude shifting from northern to the southern part.The relationship between the species richness and coverage was positive correlation in three northern transects,but the correlation between the species richness and coverage was low in the southern transects.The reason may be that few species dominated the community in the southern transects.At last,the vegetation ecology study foreground of Tibet Plateau was described in the paper.The distribution pattern of species richness and the environmental cause may be an important study direction in the future.

Key words: QinghaiTibet Railway, transects, species richness, coverage, relationship