Abstract: The objectives of the present study were to discuss the status and utilization of resources and the mutual relationship of dominant plant population, to reveal the stability of phytocoenosium and ecological adaptability of plant population under the specific environment, to accumulate theory data for further research on Alsophila spinulosa competion with other species, meanwhile, to provide reference of the protection, utilization and related research for China Danxia world natural heritage. Based on the sample investigation of A.spinulosa community of Danxia Landform in North Area, Guizhou, with the method of quantitative analysis, the niche breadths proportional similarity and overlaps of main dominant species were measured using a series of indices proposed. The results showed that the niche breadth values of Brassaiopsis glomerulata, Maesa japonica and A.spinulosa are the biggest, Shannon Wiener indices were 7.607 6, 7.344 9 and 6.910 5, Levins indices were 0.531 4, 0.593 1 and 0.651 5, respectively, which showed that they are all widely distributed within the community, having strong ability to adapt to the environment; Cinnamomum wilsonii and Mallotus repandus niche proportional similarity value was 0.998 6, it was the biggest in all species pairs; Ficuslaceratifolie Levl and Beilschmiedia delicata niche overlap values were the biggest, the index was 0.336 5. Normally, if the niche breadth of the species pairs is wider, the interspecific niche proportional similarity value is higher, niche overlap is also bigger, but niche overlap and niche proportional similarity of some species does not necessarily high. It was closely related to ecological and biological characteristics of species. From the view of the distribution pattern of niche overlap and proportional similarity, there were generally niche overlaps among main populations, but the niche overlaps were mostly at low level, indicated that the interspecific competition generated by utilizing same resources or occupying specific resources was not intense, and the environmental resources could be sufficiently shared by different populations. The Alsophila spinulosa forest communities of Danxia Landform in North Guizhou were at relatively stable stage.

Key words: Alsophila spinulosa community, niche breadth, niche proportional similarity, niche overlap, Danxia landform, North area of Guizhou