Study On Species Diversity And Functional Diversity Of A Natural Secondary Forest In Qingling Mountain, China

In recent years,the proportion of functional diversity research has increased year by year.In this paper,based on the field distribution and comprehensive investigation,according to the concentration and typicality of the natural secondary forest distribution in the Qinling Mountain,40 plots were selected along the elevation as the research object.By selecting the four functional traits of plant seed diffusion,pollination,plant height,photosynthesis,nitrogen fixation,growth,growth cycle,leaf shape,root system,flowering duration,flowering stage and fruit ripening stage,Convex hull hyper-volume FRic,Functional evenness FEve,Functional dispersion FDis,Quadratic entropy RaoQ,four functional diversity indices,combined with species diversity indices,to study the relationship between species diversity and functional diversity of Qinling Mountain.The classification and ranking of research plots were carried out to analyze the correlation and degree of species diversity and functional diversity of different community types,which provided a theoretical basis for the biodiversity conservation and sustainable use of natural secondary forest communities in Qinling Mountain.1.There are 347 species of 235 genera belonging to 79 families of natural secondary forest plants,including 6 species,8 genera and 8 species of pteridophyta;1 family,5 genera and 5 species of gymnosperms and the rest are angiosperms.Monocotyledons have 7families,37 genera and 49 species,and dicotyledons include 65 families,185 genera and 285 species.2.The trend simulations between elevation and species diversity indices show obvious trend of single peak curve,that is,the species diversity indices are larger in the middle elevation area than in the high elevation area and low elevation area,there are biggest between 1600 m and 2000 m.Convex hull hyper-volume and functional evenness are affected by the elevation have same trend with species diversity indices.Functional dispersion and Quadratic entropy are significantly positively correlated with the elevation.3.Functional dispersion FDis and Quadratic entropy RaoQ are extremely significantly positively correlated.The four functional diversity indices can be divided into three categories: Convex hull hyper-volume FRic reflects functional richness factor,functional evenness FEve reflects functional evenness factor;functional dispersion FDis and Quadratic entropy RaoQ reflect functional dispersion factor.4.Species richness,species diversity and functional richness were extremely significantly positively correlated,and species dominance and functional richness were significantly positively correlated.In addition,there is a extremely significant positive correlation between species richness,dominance and diversity.Species evenness with species dominance and species diversity are significantly positively correlated,and positively correlated with species richness.5.The 40 survey plots were divided into 8 communities by Two-way indicator species analysis.Different communities had clear scope and boundaries in Canonical correspondence analysis,which verified the correctness of the classification results.6.The species diversity in different communities is different.The characteristics of herb layer > shrub layer > tree layer are obvious in Betula platyphylla,Betula albosinensis,Abies fargesii and Picea asperata.Pinus tabuliformis,Quercus variabilis,Pinus armandii and Quercus aliena var.acuteserrata communities showed the distribution of shrub layer > herb layer > tree layer.7.From the whole communities analysis,the species richness and species diversity of Pinus armandii community is the highest,and its functional richness and functional evenness is the highest.The functional dispersion of Pinus tabulaeformis community is the largest.The difference of species dominance and species evenness among different communities are small;In terms of ? diversity,the differences between the communities of Pinus tabuliformis,Quercus variabilis,Pinus armandii and Quercus aliena var.acuteserrata which growing in relatively low elevation areas are small.The differences between the communities of Betula albosinensis,Abies fargesii and Picea asperata which growing in relatively high elevation areas are small.