Studies On Flora And Ecology Of Bryophytes In Hangzhou City, Zhejiang Province, China

Hangzhou not only is one of the most important cities in the delta of Yangtz River and the important traffic hinge in southeast of China, but also is well known for its tourism and cultural history. Based on the extensive field specimen collection and ecological quadrat investigation, studies of the bryoflora and ecology of bryophytes in Hangzhou city were undertaken for the first time. The main results are as follows:1. Characteristics of bryophytes diversity in HangzhouBased on the investigation and more than 1200 specimen identification of bryophytes from Hangzhou city, 241 species in 110 genera and 55 families of bryophytes were reported. Of these, 52 species, belonging to 27 genera and 22 families, were liverworts. 189 species, belonging to 83 genera and 33 families, were mosses. Leskeella pusilla (Mitt.) Nog. is new to China. Seven species and three genera are new to Zhejiang province. The characteristics of dominant families and genera in Hangzhou were also discussed.2. Floristic analysis of bryophytes in HangzhouThe bryo-diversity in Hangzhou is rich and its bryoflora could be divided into ten geographical elements. Of those, East Asian, North Temperate and Tropical Asian elements account for 38.24%, 25.49% and 15.69%, respectively. It implied that the bryoflora of Hangzhou had a transitional characteristic from sub-tropic to northern temperate zone. The relationships of bryoflora among Hangzhou and six selected areas, namely Jiuwan Mountain of Guangxi, the eastern Jiufeng Mountain of Fujian, Jinfo Mountain of Sichuan, Shanghai, Kunyu Mountain of Shandong and the eastern Tianshan of Xinjiang were analysed and studied. The species abundance, major families, generic similarity coefficient and geographical elements of these areas were compared. The result of cluster analysis, according to floristic spectrums of the seven areas, showed that the bryoflora of Hangzhou was close to those of Jiuwan Mountain, the eastern Jiufeng Mountain and Jinfo Mountain, all locating in subtropical zone, while the eastern Tianshan was far from the other areas. The comparison results also indicated the transitional characteristic of bryoflora of Hangzhou.3. Ecological study on bryophytes in urban areas of Hangzhou(1) The bryophytes, their frequency and coverage on the ground in twenty-four sites in urban areas of Hangzhou were investigated and sampled. Based on 102 recorded bryophytes species and their importance value, Detrended Correspondence Analysis was used to analyse their distribution patterns. The results showed that the study sites could be divided into two groups. Group one included fourteen sites in the southwest of Xi Lake, with relatively abundant bryophytes species. The other group included ten sites, which were in the parks surrounding Xi Lake and greenlands in urban areas of Hangzhou. It had fewer bryophytes occuring in the sites, and their biodiversity index, such as Shannon-Wiener, Patrick, were lower than those of sites in the former group.(2) Canonical Correspondence Analysis was applied to study the relationships of forty-seven species of bryophytes and the environmental factors in twenty-three sample plots. The results revealed that the influence of human activities and the pH conditions of the soil were the most important factors to determine the distribution of bryophytes on the soil in urban areas of Hangzhou. With more human disturbance, the pH of the soil in urban parks and greenlands were alkali, while the conditions in hill areas, with little human disturbance, turned out to be acidic.(3) Canonical Correspondence Analysis was also applied to study the relationships of seventy-nine species of bryophytes and the environmental factors in nineteen saxicolous plots. The results showed that the influence of human activities was the most important facor influencing the distribution of saxicolous bryophytes for the sample plots within tourism sites and parks in urban areas of Hangzhou, while canopy density, relative humidity and altitude were the major factors for the sample plots within hill areas surrounding the Xi Lake.(4) The niche width of forty-six main bryophytes species in the twenty-four sample sites in urban areas of Hangzhou were calculated. It revealed that most bryophytes species had very narrow niche width. Pseudotaxiphyllum pohliaecarpum was the species with the widest one in this region. The species of Trachycystis microphylla, Haplocladium angustifolium, Plagiomnium acutum and Trichostomum planifolium also had relatively wide niche width. Among them, Haplocladium angustifolium and Trichostomum planifolium were the very common species in parks and greenlands of urban areas of Hangzhou. Others were mainly occured in the hill areas.In addition, based on literature available to us, an annotated checklist of mosses in Zhejiang province was completed. 694 species, 8 subspecies and 27 varieties in 222 genera and 45 families were accepted as valid taxa. The checklist provided the useful information for future biodiversity study in Zhejiang province and China.