| The epiphytic bryophyte is an important part of bryophytes and well known as good indicator to environments due to its special substance and sensitivity to microhabitats. The Yangtze River Delta is one of ten metropolitan areas in the world. There is no special research focusing on biodiversity and ecology of epiphytic bryophytes in Yangtze River Delta. Based on field investigation and sampling, by means of analysis methods of biodiversity and quantitative ecology, the biodiversity and ecology of epiphytic bryophytes in Yangtze River Delta were systematically studied. The main results are as follows:1. Based on the field investigation and identification of about 3000 specimen collected from 67 sample sites, 27 families, 63 genera and 118 species of epiphytic bryophytes were recorded in Yangtze River Delta. Among them, 17 species belonging 6 families, and 10 genera are liverwort, 101 species belonging to 21 families, and 53 genera are mosses. The analysis results showed that the distribution of epiphytic bryophytes was effected by the tree species and habitats. The main epiphytic species include Schwetschkea courtoisii, Haplocladium microphyllum and Entodon obtusatus etc.2. The species biodiversity and distribution of epiphytic bryophytes of ten main cities in the area were analyzed byβ-diversity index and polar ordination method. The results indicated that ten main cities could be divided into three main city groups: Group1 includes six cities, namely, Shanghai, Nanjing, Hangzhou, Suzhou, Wuxi and Zhengjiang with high bryophytes biodiversity; Group2 include Yangzhou, Yixing and Nantong, three relatively small cities with less bryophytes biodiversity; Group3 consists of Changzhou with poor bryophyte biodiversity. The results were corresponded to similarity urban structure and regional climate condition in three groups.3. Based on sampling of species and coverage of epiphytes at 18 sites in Shanghai city, a total of 43 species in 31 genera of 16 families were identified, and ecology of the epiphytic bryophytes in Shanghai city was studied with different ecological analysis methods. (1) The relationships between epiphytic bryophytes and habitat factors were analyzed by means of DCA, Spearman rank correlation, CCA. The results showed that host specificity of epiphyte bryophytes to the tree species was not significant. On the contrary, the height and direction on tree trunk where the bryophytes grow had an important effect on species and community structure.(2) Analysis of distribution pattern of epiphytic bryophytes in Shanghai city with TWINSPAN and DCA methods indicated that 18 sample sites could be divided into 4 groups. The division was well correlated to the environments.(3) The niche breadth and the niche overlap of epiphytic bryophytes in the city were calculated. The results showed that the most epiphytic bryophyte species with niche breadth less than 0.1, accounted for 67.44% of the total had rather narrow niche breadth.(4) The interspecific association of the dominant epiphytic bryophyte species was analyzed by using variance ratio test, Jaccard association index, Pearson's correlation coefficient and Spearman rank correlation. The results indicated that the significant association between species of epiphytic bryophyte in Shanghai was few. The overall association index (VR) tended to negative with the increase of air pollution and habitat disturbance,.4. The epiphytic bryophytes of 17 sites in Nanjing city were sampled. 40 species in 29 genera of 16 families of epiphytic bryophytes were recorded. The results of ecological studies showed 17 sample sites could be divided into 4 groups for reflecting the distribution pattern of epiphytic bryophytes. The niche breadth of the most epiphytic bryophytes in Nanjing was also narrow, with 85% of the total species have the breadth less than 0.1. Compared with Shanghai, The specific composition of the epiphytic bryophytes in Nanjing is similar with that in Shanghai, but Nanjing has more hygrophilous species.
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