Diversity and distribution of bryophytes and their relationship with environmental factors in Wuhan

Bryophyte communities and correlated urban environments in Wuhan were investigated from September to November in 2016. A total of 431 bryophyte specimens were collected from 73 plots in 26 sampling sites along seven central urban areas and suburban areas. We recorded 91 bryophyte species,belonging to 35 genera and 20 families,in the study area. According to the importance values,Haplocladium angustifolium and Entodon obtusatus were the dominant species,and were widely distributed in 24 sites. The species richness and Shannon-Wiener index of bryophytes in Qinglongshan national forest park were the highest, suggesting that the bryophyte community was highly complex in this site.According to the Pearson correlation analysis,the environmental factors that affected the diversity of ground bryophytes were soil water content and distance to main roads,with distance to main roads also related to the diversity of epiphytic bryophytes. Canonical correspondence analysis( CCA) was used to evaluate the relationships between the variousbryophyte species and environmental factors in the 26 sample sites. Results indicated that human disturbance,herb coverage,and distance to main roads had significant impacts on the distribution of ground and epiphytic bryophytes in Wuhan. The effects of human disturbance and herb coverage on the distribution of ground bryophytes were the most significant,whereas tree trunk diameter at breast height and distance to main roads in the city had the most significant effects on the distribution of epiphytic bryophytes. This study illustrated that bryophyte diversity and distribution are impacted by human disturbance in Wuhan,and epiphytic bryophytes are more sensitive to automobile exhaust.