| Urban bryophyte is an important part of urban green space ecosystem.It is an indicator species that can directly reflect the quality of urban air and environment.The changes of community quantity and species composition can directly or indirectly map the dynamic balance of urban ecosystem.Studying its species diversity in urban green space is of great significance for protecting bryophyte germplasm resources and exploring its application in urban greening construction.This paper hopes to explore the diversity and distribution characteristics of bryophytes in different types of urban green space,reveal the growth and distribution law of bryophytes in urban green space,as well as their structure,function and status in green space ecosystem,and explore the response of bryophytes to urbanization environment,so as to lay a foundation for the protection of urban bryophyte germplasm resources,And further promote the protection and restoration of urban biodiversity.Taking the urban green space around Hefei Ring Park as the research area,referring to the setting method of urban biodiversity observation area by Cubu urban biodiversity research team,taking into account the spatial distribution of urban green space and the distribution characteristics of bryophytes in Hefei,this study selects three different types of9 typical green spaces around the first ring,including 142 sample plots of 200m2,for bryophyte diversity investigation.This paper analyzes the species diversity and distribution characteristics of bryophytes in different types of urban green space,takes the Patrick richness index,Shannon diversity index and Pielou evenness index of bryophytes as indicators,and uses correlation analysis and regression analysis to explore the impact of environmental factors of different types of urban green space on the growth and distribution characteristics of bryophytes in green space.The results show that:(1)A total of 41 species of terrestrial bryophytes belonging to 31 genera and 20 families were observed in 142 plots and 710 standard plots in 9 urban green spaces,including 2 species of liverworts belonging to 2 families and 2 genera,and 39 species of mosses belonging to 29 genera and 18 families.According to the definition of dominant species,Pottiaceae,Dicranaceae,Brachytheciaceae,Bryaceae are the dominant species in the sample plot.The geographical composition of the flora shows that there are 13 geographical components in the sample plot,mainly in the north temperate zone and East Asia,with obvious temperate and tropical distribution.The overall bryophyte life forms are not rich,and most bryophyte life forms tend to drought tolerant,among them,there are 23 cluster types,12 intertwined types,2 tile types,1 inclined type and 1 tree type,reflecting the adaptability of bryophytes to urban environment.The evenness index of bryophytes in the sample plot is between 0.50-0.65,the distribution of bryophyte coverage is relatively uniform,and the similarity index is between 0.09-0.73.The similarity is low,which is related to the great difference of environmental factor indexes such as soil humidity,canopy density and human disturbance intensity.(2)511 arbors,249 shrubs and 177.5m2 grass cover were measured in 142 sample plots.The species of arbors,shrubs and grasses belong to 64 species,59 genera and 35 families.There are 24 species of single family and single genus plants and 55 species of single genus and single species plants in the sample plot,showing the characteristics that single family,single genus and single species plants are the main tree species.The vegetation community structure of all kinds of land is mostly arbor grass and arbor shrub grass structure.Except that Jixi new village of foreign trade province is a broad-leaved mixed forest,other green spaces are coniferous and broad-leaved mixed forest.The study found that the composition of arbor,shrub and grass plants in various land is different.The reason is that the type of green space and its functional demand are the dominant factors affecting the richness proportion of vegetation types in various land.(3)It is found that bryophytes such as Plagiomnium T.Kop.and Entodon cladorrhizans(Hedw.)C.Muell.are mainly distributed in humid environment;Haplocladium microphyllum(Hedw.)Broth.and Haplocladium angustifolium(Hampe et Müll.Hal.)Broth.grow in open environment;Brachythecium fasciculirameum Müll.Hal.and Meteorium papillarioides Nog.have strong drought resistance and are mostly found in arid areas;Dicranum scoparium Hedw.and Scopelophila cataractae(Mitt.)Broth.do not like direct sunlight,and are mostly distributed in areas with large canopy density and light scattering;Brachymenium exile(Dozy et Molk.)Bosch et Sande Lac.and Bryum argenteum Hedw.have strong resistance to the interference of urban environment,and are mostly distributed in areas with high degree of human interference and frequent access.In general,different bryophytes have different niches and have their own adaptive advantages.Different urban green spaces provide suitable growth environment and resources for bryophytes.In different types of green spaces,different soil humidity,canopy density(light),human disturbance and other environmental factors make the bryophytes observed in the site different.(4)Through the in-depth analysis and research on the influencing factors,it is found that the tree species structure,canopy density,soil index and human disturbance degree have a high correlation with the richness and diversity of bryophytes.The regression analysis results show that the effects of soil humidity,canopy density and human disturbance degree on the richness and diversity of bryophytes have reached a significant level,The results show that among the multiple influencing factors,these three influencing factors are the main factors that significantly affect the distribution of bryophytes,and the influence on the uniformity of bryophyte Pielou is that in addition to the measured environmental factors in the sample plot,other environmental factors still play an important role.The equation of bryophyte richness and Bryophyte diversity is obtained by stepwise regression:a:Y(BR)=-1.604*(HD)+0.25*(SM)+3.969BR: moss richness(species);HD:degree of human interference;SM:soil moisture(%)b:Y(BD)=-0.206*(HD)+0.024*(SM)+0.553*(CD)+1.164BD:Bryophyte diversity;HD:degree of human interference;SM:soil moisture(%);CD:Canopy density(%)... |
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