Study On Species Diversity And Phylogenetic Diversity Of Typical Shrub Plant Communities In Henan Province

Shrubs are important in terrestrial ecosystems.The study on the biodiversity of shrub plant community and its relationship with environmental factors is the basis for vegetation development and sustainable use of shrub resources.It is an important part of vegetation ecology and also has important theoretical significance and practical reference value.In this paper,the mountain shrub plant communities in Henan Province were investigated.We studied the basic information of plant communities and environmental factors in the field,combining soil determination and data analysis.We summarized the main types of the shrub community to find out the relationship between these two biodiversity and environmental factors,for the purpose of enriching the background data of the shrub community in the area,hence providing reference and basis for the biodiversity conservation,shrub development and sustainable use of plant resources.We used four species diversity indices to measure the species diversity of shrub plant community and two indices to measure the phylogenetic diversity of shrub plant communities.We analyzed species diversity of typical shrub plant communities by one-way analysis of variance and used CCA(Canonical Correspondence Analysis)method to sort the communities and environmental factors.We also analyzed the correlations between species diversity,phynogenetic diversity,and environmental factors using Pearson correlation analysis.To analyze the linear trends of phylogenetic diversity to environmental factors,linear regression was used.The main conclusions of the study are as follows:We recorded 317 species by investigating 153 shrub plots and 459 herbaceous plots from 51 plots of shrub communities in our study area.These species belonged to 87 families and 217 genera,including 138 shrub species(45 families,94 genera)and 179 herb species(42 families,123 genera).Totally,23 community types were recorded,including Vitex negundo var.heterophylla shrub,Rhus chinensis shrub,Rhododendron concinnum shrub,Gleditsia microphylla shrub,Carpinus turczaninowii shrub,Cotinus coggygria shrub,Quercus acutissima shrub,Pistacia chinensis shrub,Spiraea pubescens shrub,Forsythia suspensa shrub,Ziziphus jujuba var.spinosa shrub,Leptopus chinensis shrub,Campylotropis macrocarpa shrub,Quercus baronii shrub,Rubus coreanus shrub,Celastrus orbiculatus shrub,Salix matsudana shrub,Lespedeza buergeri shrub,Broussonetia papyrifera shrub,Berchemia floribunda shrub,Juglans mandshurica shrub,Castanea mollissima shrub,Ailanthus altissima shrub.We calculated species richness,Shannon-Wiener diversity index,Simpson diversity index and Pielou evenness index to test the biodiversity of different community types.As for the species richness,it was Rhus chinensis-Imperata cylindrica shrub the highest in the shrub layer,and the Vitex negundo var.heterophylla-Bothriochloa ischaemum shrub the lowest.When it came to the herbaceous layer,it was Rubus coreanus-Dendranthema indicum shrub and Rhododendron concinnum-Cirsium leo shrub the highest,and Quercus acutissima-Themeda japonica shrub the lowest.As for the Shannon-Wiener index H' and Simpson index D,it was Rhododendron concinnum-Laportea bulbifera shrub the highest in the shrub layer,and the Vitex negundo var.heterophylla-Bothriochloa ischaemum shrub the lowest.When it came to the herbaceous layer,it was Rhododendron concinnum-Cirsium leo shrub the highest,and Quercus acutissima-Themeda japonica shrub the lowest.As for the Pielou evenness index J,it was Vitex negundo var.heterophylla-Setaria viridis shrub the highest in the shrub layer,and the Vitex negundo var.heterophylla-Bothriochloa ischaemum shrub the lowest.When it came to the herbaceous layer,it was Gleditsia microphylla-Ceratostigma plumbaginoides shrub the highest,and Quercus acutissima-Themeda japonica shrub the lowest.We sorted the relationships between shrub layer species and herb layer species and environmental factors of shrub communities with CCA.In shrub layer,the cumulative proportion of species distribution changes explained by the constrained axes was 16.7%,and 10.04%by the first two axes.When it came to herb layer,14.92%and 8.98%,respectively.There were five environmental factors affecting the species diversity and species distribution based on the first two axes.That was,elevation,annual average temperature,soil pH,annual average precipitation and soil total nitrogen in shrub layer,and soil pH,elevation,annual average precipitation,soil total nitrogen and annual average temperature in herb layer.Among the indices we used to characterize the phylogenetic diversity of,NRI(Net Relatedness Index)reflected the clustering degree of species better,and NTI(Nearest Taxon Index)reflected the degree of local dispersion better in the community.Both the shrub layer and the herb layer were phylogenetically clustered in typical shrub communities in Henan Province.The degree of clustering of the shrub layer decreased significantly with the slope increasing.The degree of clustering of herb layer increased with the elevation,and the soil organic matter and total nitrogen content decreased significantly,with the increase of annual average temperature and soil pH.With the increase of altitude and the decrease of soil organic matter and total nitrogen content,the degree of phylogenetic clustering of herb layer decreased.And with the increase of annual average temperature and soil pH,the degree of phylogenetic clustering of herb layer increased.The relationships between species diversity and phylogenetic diversity and environmental factors were complicated and influenced by multiple factors.We should consider multiple diverdity indexes in the resource conservation,development and utilization of shrub plant resources.Our results can provide a data support and theoretical basis for biodiversity conservation and construction of ecological civilization for local government.