Diversity Of Bryophytes In The Northern Mountains Of Yanshan

As the ecological barrier of Beijing,the mountains to the north of Yanshan mountain are the main part of the northern forest in China.Bryophytes are higher plants with a simple structure.They are an important part of forest ecosystems and species diversity.They affect the succession of forest communities and play an important role in maintaining biodiversity and maintaining the stability of forest ecosystems.It is of great significance to carry out research on the diversity of bryophytes in the northern part of Yanshan Mountains for the protection and sustainable utilization of bryophytes in this area.In this paper,the outline of the northern mountainous area of Yanshan Mountain is divided into four directions,east,west,north and south,and sampling points are set up in the study area,and then the field collection,specimen sorting and identification,data processing and analysis of bryophytes are carried out.The diversity analysis of the area is as follows:(1)A total of 40 families,106 genera and 274 species of bryophytes(including varieties and subspecies)have been found in the northern mountainous area of Yanshan Mountain,including 13 families,17 genera and27 species of liverworts,and 27 families,89 genera and 247 species of mosses.Through the comparison of families,genera and species,it is concluded that there are 6 dominant families in the study area,namely Pottiaceae,Bryaceae,Brachytheciaceae,Hypnaceae,Amblystegiaceae,and Mniaceae.There are 51 genera,accounting for 48.1% of the total number of genera,and 168 species,accounting for 61.3% of the total number of species.There were 5 dominant genera,namely Bryum,Didymodon,Brachythecium,Hypnum,and Entodon,with a total of 60 species,accounting for 21.90% of the total.(2)Based on the distribution characteristics of mountain bryophytes in the northern part of Yanshan Mountain,9 geographical distribution types were divided,among which the northern temperate zone had the highest component,containing 156 species,accounting for 65.82% of the total species,followed by East Asian components,followed by China-endemic components,indicating that the study area The northern temperate zone is dominant and has East Asian characteristics.Because the northern mountainous area of Yanshan is located at the northern end of China,it has China-specific ingredients and less tropical ingredients.(3)Statistics on the number of moss species in different altitude ranges in the northern mountainous area of Yanshan show that bryophytes are most abundant in the A4(1300-1500 m)range,and the A2(900-1100 m)range is the least species.On the basis of A2,the percentage of the total number of mosses in the rest of the interval to the total number of species almost increased exponentially.(4)Research on bryophyte diversity in different altitude ranges in northern Yanshan Mountains: ? diversity shows that the Shannon diversity index and Margalef richness index in different altitude ranges in northern Yanshan Mountains have the same trend of change,showing first decline,then rise and finally decline.The trend of Simpson dominance index was opposite,but the overall richness of bryophytes in the northern part of Yanshan Mountain was relatively high.The Pielou evenness index indicates that the individual evenness of the region is similar.For ?-diversity research species,the Cody difference index shows that the bryophytes have the fastest rate of change in the two altitude intervals of A1(500-700 m)and A6(1900-2100 m);the Jaccard similarity index A2 and A6 two altitude intervals species change Great replacement.Through cluster analysis,it was concluded that A3 and A5 had the shortest clustering distance and the closest kinship.(5)By studying the composition of bryophytes in different habitats in the northern mountainous area of Yanshan,it is concluded that rock surface > soil >epiphyte > saprophytic.By analyzing their species similarity coefficients,it can be seen that soil and rock surfaces have the most of the same species,and the species similarity coefficient is the highest,followed by epiphytic and saprophytic bryophytes,the similarity index of rock surface and saprophytic bryophytes was the lowest,only 0.360.