Zhongkai University of Agriculture and Engineering,China
Title: Study on Community Structure and Diversity of Three Wild Cycas Plants in Baise, China
Abstract: Cycads are most primary seed plants, and are also rare and conserved plants, in order to provide references of theoretical research, protection and reasonable resource utilization of Cycas plants, and improved the research on diversity of subtropical mountain vegetation, we study the species composition, community structure and plant diversity of three Cycas plant communities in Baise. We used sample plot survey method to investigate three Cycas plant communities which located in different counties in Baise region, China, analysed species composition, community structure characteristics, speciesα-diversity and β-diversity among the three communities. The results showed that there are 38 families, 63 genera and 75 species of vascular plants in the three communities. The proportion of one family and one genus containing only one species in each community were higher. the situations of average height and layer coverage is as followed: Com.Cyclobalanopsis glauca-Cycas guizhouensis-Lophatherum gracile (community 2) > Com.Microcos paniculata-Broussonetia kazinoki-Elatostema involucratum (community 3) > Com.Alangium chinense-Toona ciliata-Lepidagathis incurve (community 1). Except the important value of Cycas guizhouensis is the first position in shrub layer, the dominance of Cycas baiseensis and Cycas xilingensis in their respective communities is not high. The species diversity, richness and evenness of the three communities were community 3 > community 1 > community 2. The similarity coefficients of species among three communities were low, ranging from 0.0400 to 0.1887. The similarity coefficients of families and genera decreased with the increase of distance gradient of each community, showed that the plant diversity is higher because of the difference of geographical environment in the Biase region. The possible factors influencing the population size of Cycas plants in this study were: the circumstance of tree layer’s structure characteristics, whether the Cycas population and its community were disturbed by human activities and so on. Refer to the actual situation of each Cycad plant population and it’s community, it is suggested that in situ conservation strategy should be adopted for Cycas guizhouensis, Cycas baiseensis and Cycas xilingensis shall be same time used in situ conversation and ex-situ conservation strategy.