Habitat community characteristics and species diversity of Chimonanthus nitens in Wuxi River Basin, Suichang

Key words: 
• Chimonanthus nitens /
• flora /
• species composition /
• community structure /
• species diversity /
• Suichang /
• Wuxi River Basin

Abstract:   Objective  Chimonanthus nitens is a rare wild plant unique to China both for tea and medicine. The wild resources have been seriously damaged with the development of its medicinal function and the increase of market demand. This study aims to explore the structure characteristics and species diversity of the habitat community of C. nitens population, as well as its suitable living environment, so as to provide a scientific basis for the protection, development and utilization of C. nitens population.   Method  Based on the field survey, the typical community of C. nitens was selected in Wuxi River Basin of Suichang, and five 400 m² plots were set up to investigate and analyze the flora, species composition, community structure and species diversity of the community.   Result  (1) The flora of C. nitens community was dominated by pantropical distributions, disjuncted distribution in East Asia and North America, and northern temperate distribution. The proportions of tropical and temperate genera were 50.70% and 40.85%, respectively, with typical characteristics of mid-subtropical flora. (2) There were 105 species in the 2000 m² sample plots, belonging to 80 genera and 47 families. The families and genera were rich in species and dispersed in composition. The dominant families were Lauraceae, Rosaceae, Fagaceae, Fabaceae and Rubiaceae. (3) The diameter class structure of C. nitens population and habitat community was an inverted “J” type, indicating a growth type. The top 5 tree species with important values of the arbor layer were Cunninghamia lanceolata (11.67%), C. nitens (11.63%), Castanopsis sclerophylla (9.05%), Loropetalum chinense (7.28%) and Lithocarpus glaber (7.08%). The vertical structure of the community was rich. K-means clustering showed that individuals with DBH≥1 cm in the tree layer could be divided into five forest layers according to the tree height. The main location of the community was in the tree layer Ⅰ [1.0, 4.5) m and tree layer Ⅱ [4.5, 7.0) m. (4) The species diversity index varied greatly in different regions. Margalef index, Shannon-Wiener index, Simpson index, Pielou index and Dominance index were 1.98−3.84, 1.56−2.37, 0.72−0.87, 0.69−0.86 and 1.98−3.85, respectively.   Conclusion  The community of wild C. nitens in Wuxi River Basin of Suichang has rich species composition and complex vertical structure. Small and medium diameter trees account for the vast majority, which is an increasing community with high species diversity as a whole. Under the premise of protecting the existing community habitat, it is suggested to carry out experiments imitating wild cultivation to rationally develop and utilize the wild resources of C. nitens. [Ch, 2 fig. 7 tab. 26 ref.]