Study On Bryophyte Diversity In Guizhou Xishui National Nature Reserve

Guizhou Xishui National Nature Reserve is one of the most important nature reserves in the priority areas of biodiversity conservation in the Ta-lou Mountains on the Guizhou Plateau and Wuling Mountains in China.The main protection objects are the forest ecosystem and wild animals and plants of the middle subtropical evergreen broad-leaved forest.The distribution of primary vegetation in the reserve is concentrated and the area is large,which is very rare in the same latitude on the earth.It is one of the most representative typical regions in the study of subtropical evergreen broad-leaved forest ecosystem in China and even in the world.Through field investigation and specimen collection of bryophytes,A total of 3429 bryophyte specimens were obtained in Xishui National Nature Reserve,Guizhou.After specimen identification and data statistical processing,bryophyte species diversity,floristic geographical composition,life form composition,habitat diversity and epiphytic bryophyte diversity of forest trees with different vegetation were analyzed.The main results are as follows:(1)There are 591 species(including subspecies and varieties)of bryophytes belonging to 177 genera and 71 families in Xishui National Nature Reserve of Guizhou Province,including 424 species of bryophytes belonging to 134 genera and 41 families,165 species of bryophytes belonging to 41 genera and 26 families,and 2 species of bryophytes belonging to 2 family and 2 genera.The general families,genera and species of bryophytes in the reserve accounted for 70.00%,48.79% and 36.48% of the total bryophytes in Guizhou Province,respectively.There are 16 families in dominant families,16 genera in dominant genera.(2)The floristic of bryophytes in Xishui National Nature Reserve in Guizhou are complex and diverse.The floristic of bryophytes in Xishui National Nature Reserve can be divided into 18 types,mainly in the North Temperate,followed by East Asian,Pantropical ranks third,Macroscopically,it reflects the characteristics of the confluence of Temperate and Tropical in Xishui Nature Reserve.(3)The life forms of bryophytes in Xishui National Nature Reserve in Guizhou can be divided into 9 types: Turfs,Cushions,Rough mats,Smooth mats,Wefts,Pendants,Fans,Dendroids and Leaf shape.The life form Turfs of bryophytes in Xishui Nature Reserve accounted for the highest proportion,followed by Rough mats,and the third was Smooth mats,while Cushions,Pendants and Dendroids species were no more than10 species.(4)According to the substrate,the habitat types of bryophytes in Xishui National Nature Reserve of Guizhou Province are divided into five types: on dead plants,Epilithic,Epigaeus,Epixylous and Epiphytic.The species richness of bryophytes in each habitat type is as follows:epilithic(619 species),epigaeus(466 species),epixylous(271 species),on dead plants(134 species)and epiphytic(8 species).(5)Affected by vegetation types,the types of epiphytic bryophytes of different vegetation types are significantly different.Among the four different vegetation types,the species richness of epiphytic bryophytes in coniferous broad-leaved mixed forest is the highest.The Simpsion index and Margalef index showed the same trend of change,both of which were Polyspora axillaris-Phoebe zhennan forest,Evergreen broadleaved forest,Mixed coniferous broad Leaved forest,Choerospondias axillaris forest.The Jaccard index was the lowest with Choerospondias axillaris forest,and the shared species was the least.The Jaccard index between Evergreen broad-leaved forest and Mixed coniferous broad Leaved forest was the highest,and the shared species was the most.