Studies On Species Diversity And Distribution Pattern Of Bryophytes In Wuxi City, Jiangsu Province

The city of Wuxi is located in the south of Jiangsu Province, and lies in the heartland of Yangtze delta. Wuxi, as the second biggest city, plays an important role in economics and society in Jiangsu Province. The research on bryophytes of Wuxi City is not only an important part of bryophyte diversity in Jiangsu Province but also important for the knowledge of cryptogam diversity and ecology on cryptogam biological indicator in Yangtze delta.Based on the field investigation,collection,indoor identification, 37 families 82 genera 166 species of bryophytes have been recognized, including 11 families 14 genera 22 species of liverworts and 26 families 68 genera 144 species of mosses. Five species of bryophytes are rep(?)ted new to Jiangsu Province, namely, Leiocolea bantriensis (Hook.) Steph., Brachythecium glareosum (Bruch ex Spruc.) B. S. G., Plagiothecium succulentum (Wils.) Lindb., Vesicularia reticulata (Dozy et Molk.) Broth., Pogonatum cirratum (Sw.) Brid,. 16 species of medical bryophytes are recorded and discussed in detail.According to the criteria of flora analysis of Chinese seed plants proposed by Wu Zheng-yi, eight types geographic elements are recognized. The Holarctic element, including Eurasia and North America element, East Asia and North America element and Eurasia element, is the most important, with 74 species corresponding to 44.58% of the total. Following the East Asia element, including the Chinese endemic element, the Sino-Japan element, the Sino-Himalaya element, consists of 49 species, accounting to 29.52% of the total. The old tropical element consists of 18 species, about 10.84% of the total.The results of comparison of floristic components with other areas in China by cluster analysis showed that the bryoflora of Wuxi City is the transition from temperate zone to subtropical zone, which confirms the Chen Pangchieh's (1958) treatment about the Chinese bryophyte floristic area division.According to the habitats and ecological environments, the bryophyte communities in Wuxi City can be divided into four types, including hydrophytia,petrophytia, geophytia and epixylophytia. Among them, petrophytia and geophytia are most widely distributed, and only few hydrophytia are found. This shows the complex of habitats in this area.Based on sampling data of the species and coverage content, the family,genera and species diversity of each site was analyzed. The results showed the composite of family,genera and species in each site is related with the habitats. Cluster analysis demonstrates that the bryophyte sites in Wuxi City can be divided into three groups, and the composite of species and coverage content in each group manifest the bryophyte distribution pattern in Wuxi City. CCA was used to analyze the correlation...