Community Structure and Species Diversity Analysis of Rare Plant Disanthus cercidifolius var. Longipes in Qianjiangyuan National Park

Understanding the community structure of the rare plant Disanthus cercidifolius var. longipes can provide a basis for the protection of this species. By taking the community of Disanthus cercidifolius var. longipes in Qianjiangyuan National Park as the research object, the plant species composition, quantitative characteristics, species diversity, vertical and diameter structure of the community were studied by using the standard plot method. The results showed that there were 108 species of vascular plants in the Disanthus cercidifolius var. longipes community, belonging to 47 families and 88 genera. The vertical structure of the community was obvious. The dominant tree species in the tree layer were D. cercidifolius var. longipes and Cunninghamia lanceolata. The dominant species in the shrub layer were Eurya rubiginosa var. attenuata, Itea chinensis var. oblonga, and Symplocos anomala. The dominant species in the herbaceous layer was Woodwardia japonica. The number of phanerophytes was the largest in the life form of plants in the community, accounting for 85.2%. Pantropical families and genera were the most geographical components, accounting for 20.90% and 20.78% of the total number of families and genera, respectively. The Shannon-Wiener diversity index, Simpson dominance index and Pielou evenness index of the plants were all in the order of tree layer > shrub layer > herbaceous layer. The tree height and diameter class structure of the community were inverted “J”-shaped, and the diameter class distribution of the single species of D. cercidifolius var. longipes showed a positive skewed distribution. In summary, the community of D.cercidifolius var. longipes in Qianjiangyuan National Park had a mature and stable structure, and its renewal status was good. The single species of D. cercidifolius var. longipes was in the stage of population succession of the increasing type.