Study On Distribution Pattern Of Huperzia Serrata Populations In Western Hunan

Huperzia serrata populations distributed in a wide area, but mainly distributed in the south-east and center-south of China. Lots of Huperzia serrata plants growing in pure forests at both sides of the ridges between altitude 300 and 1700 meters. In areas of western Hunan, such as Mt.Baiyun National Nature Reserve in Baojing, Mt.Huping National Nature Reserve in Changde and Mt.Badagong National Nature Reserve in Sangzhi, Huperzia serrata populations were sporadic distributed. In this article, Mt.Baiyun, Mt.Badagong and Guzhang were selected as the sample areas. The population distribution pattern of Huperzia serrata in these three sample areas were studied. The results illustrated the spatial pattern characters and the dynamic changing progress of Huperzia serrata populations in different habitats of western Hunan. Then, the biological and environmental factors, which acted as the key factors affecting the population distribution pattern of Huperzia serrata, were analysed and the reasons leading to the population distribution pattern of Huperzia serrata were discussed.The population distribution pattern of Huperzia serrata in different communities of western Hunan were studied by using the following measures: variance/mean ratio, index of Morisita, negative binomial parameter, index of Cassie, clump intensity, mean crowding, index of patchiness, index of Green and the test for fit to the Poisson and Negative binomial and Neyman distribution of contagious distribution. The results indicated that Huperzia serrata population showed clumped distribution and Neyman distribution. The formation of this pattern mainly resulted from its biological characteristics of reproduction, the special condition of environment and its endophytic fungi.In different habitats, the population distribution pattern of Huperzia serrata were different. Pattern scale and pattern intensity were unrelated. In different communities, the pattern scale of Huperzia serrata populations were nearly same, but the pattern intensity were different, which showed that the pattern intensity of Huperzia serrata populations significantly affected by the environment of different plots. At the same time, the pattern texture of Huperzia serrata populations were nearly same in different communities, which indicated that the size of patches were distinctly affected by the microenvironment of Huperzia serrata plants and the size of gaps were closely related to the environmental heterogeneity.In order to investigate patterns of phenotypic trait variation in natural populations of Huperzia serrata, we measured nine morphological traits in fifteen Huperzia serrata populations in areas of western Hunan. The results showed that inter/intro population variation occurred remarkably among most morphological characters, such as length of upper leaf, width of upper leaf, length-width ratio of upper leaf, diameter of stem, length of bottom leaf, length-width ratio of bottom leaf, plant height and internode length. Based on the morphological characters, cluster analysis showed that 15 populations of Huperzia serrata had been divided into 3 parts. Principal component analysis showed that five characters including length of upper leaf, length-width ratio of upper leaf, diameter of stem, plant height and internode length were mainly factors which accounted for morphological variation of Huperzia serrata.In this study, the Huperzia serrata population were clumped distributed and the population distribution patterns accorded Neyman distribution. The differences in pattern scale were not significant, the pattern texture were similar, and the pattern intensity were different. Meanwhile, the variation occurred remarkably among these characters, such as length of upper leaf, width of upper leaf, length-width ratio of upper leaf, diameter of stem, length of bottom leaf, length-width ratio of bottom leaf, plant height and internode length. In summary, all that mentioned above should be taken into account while cultivating the plants of Huperzia serrata in the future.