Plant Diversity And Its Influencing Factors In Wetlands Along The Yellow River In Henan Province

In recent years,the wetland along the Yellow River has been disturbed by human activities,and the protection of wetland plant diversity is facing great challenges.The study on the plant diversity and its influencing factors in wetlands along the Yellow River in Henan Province can help us understand the restoration and succession process of wetland community and understand the function of wetland ecosystem,which is of great significance for the protection and utilization of wetland biodiversity.In this paper,plants in the Yellow River wetland sample plot in Henan Province were taken as the main research object to comprehensively analyze the spatial distribution pattern and driving factors of wetland plant communities.Specific research results are as follows:(1)In order to explore the distribution pattern of plant community species diversity in the Yellow River wetland in Henan province,this study divided the wetland plant geographical flora,calculated the wetland plant diversity index in different regions,and compared the similarity degree of wetland communities in different regions by using Kruskal-Wallis test and Betadisper analysis.And explore the spatial distribution characteristics of wetland plants.The results showed that there were 182 species belonging to 136 genera and 46 families in the Yellow River wetland.The floristic composition is mainly tropical type and temperate type except world distribution type.The plant diversity of the Yellow River wetland decreased from west to east,and there were differences in plant community composition(F =104.26,P < 0.001).(2)In order to explore the distribution pattern of phylogenetic diversity of plant communities and the construction mechanism of wetland plant communities in the Yellow River wetland of Henan Province,this study calculated the net phylogenetic affinity index(NRI)and nearest relative index(NTI)of wetland plants in different regions of the sample plot based on the phylogenetic tree of wetland plants.Kruskal-Wallis test and t test were used to explore the distribution pattern of plant community pedigree diversity and to predict the construction mechanism of wetland plant community.The results showed that the α lineage structure of plant communities in the middle and lower reaches of the Yellow River in Henan Province was clustered and distributed,and habitat filtration had a significant effect on the construction of plant communities.However,the trend of β lineage structure aggregation and divergence existed simultaneously,and there were both habitat filtering and competitive exclusion in the process of wetland community construction.(3)In order to explore the relationship between dominant herb species in the Yellow River wetland of Henan province,19 herbs with an important value greater than 1.00% were selected to calculate the niche correlation index,and the variance ratio method(VR),Chi-square test and association coefficient(AC)were used to evaluate the degree of interspecific association of dominant herb species in the wetland.The results showed that there were significant niche differences among dominant herbaceous species in the Yellow River Wetland of Henan Province,and the overall association showed significant positive association,and the overall plant community structure showed relatively stable positive succession.The association between dominant species was weak,the interspecific structure was loose,the species independence was strong,and some communities were in unstable succession stage.(4)In order to understand the diversity and distribution of invasive plants in the Yellow River Wetland of Henan Province,this study clarified the distribution of invasive plants through vegetation investigation and identification of invasive plants,and used linear regression to explore the correlation between invasive plants and native plants.The results showed that there were 34 invasive plant species belonging to 13 families and 28 genera in the Yellow River wetland.The life types of invasive plants were dominated by annual herbs,with 23 species(accounting for 67.65% of the total species).At the scale of this study(> 25 m~2),the higher the richness of native plants,the higher the richness of invasive plants.(5)In order to explore the main driving factors of plant diversity in the Henan Yellow River Wetland,this study used redundancy analysis(RDA),Pearson correlation analysis and variance decomposition to evaluate the interpretation rates of natural environment and human disturbance on wetland species diversity and their direct and indirect relationships based on seven dynamic monitoring plots in the Henan Yellow River Wetland nature reserves.The results showed that elevation,precipitation,evaporation and longitude were the main factors affecting species distribution in the Yellow River wetland.In addition to terrain and climate,human activities is also an important factor affecting plant species diversity in the Yellow River.In conclusion,based on the Yellow River wetland plant community sample plot in Henan province,we studied the species diversity,phylogenetic diversity,niche and interspecific association of wetland plants,the composition and distribution of invasive plants,and the influence of environment on wetland plants.The results of this study can provide specific suggestions for the protection of wetland plant diversity and ecosystem restoration,and provide theoretical support for plant introduction and ecological environment protection of the Yellow River wetland in Henan province.