Abstract:In order to explore the population status of Rhododendron xishuiense, an endemic plant in Xishui National Nature Reserve, Guizhou, reveal the dynamics and endangered causes of its population and strengthen its protection, the distribution of R. xishuiense was investigated along 13 transects in the reserve. The population structure of R. xishuiense distribution community was analyzed by using four diversity indexes and Raunkiear life form, the population age structure was obtained by replacing time with space. Thus, the static life table was compiled, and the survival curve and four survival function curves were drawn to analyze the dynamic characteristics of R. xishuiense population. The results showed that there were 65 species of vascular plants in 27 families, 42 genera, in which 62 species of seed plants in 24 families, 39 genera and 3 species of ferns in 3 families and 3 genera. The number of phanerophyte was the largest with 56 species in total, accounting for 86.15% to all species, followed by chamaephyte, hemicryptophyte, and geophyte. All of diversity indexes of the community was in the order of tree layer > shrub layer > herb layer, indicating that tree layer had an absolute dominant position. The age structure of the population was pyramidal, and the number of seedlings in population was large in whole population; the population survival curve was Deevey II type, and the number of individuals decreased along age, the population survival rate continued to decline, especially in the middle and late period of rapid decline, population decline. Therefore, with its narrow distribution range and high diversity, the number of seedlings showed an increasing pattern, but due to the suffering of intense competition, the R. xishuiense had a very small population of species. It was suggested to take appropriate measures to promote the growth of seedlings and young trees, so that middle-aged individuals can be effectively supplemented, so as to ensure the sustainable growth of the population.
