Response Of Leafhopper Community Structure And Biodiversity To Ecological Restoration Of Rocky Desertification

Leafhoppers belong to Hemiptera,Auchenorrhyncha and Cicadellidae,which are widely distributed in six geographical regions of the world.Generally living in trees and grasslands,mostly herbivorous insects,feeding on a variety of plant leaves,but also some species living in the ground or plant roots,is an important part of the ecosystem.The temporal and spatial changes of leafhopper are often influenced by temperature,humidity,vegetation and other external environments.Leafhopper is a kind of insect which is sensitive to the change of environment.Up to now,there are few studies on the temporal and spatial dynamics of leafhopper community and its relationship with the external environment.In this study,three typical rocky desertification(RD)study area(Salaxi of Bijie,Huajiang of Guanling-Zhenfeng and Karst of Shibing)were selected as the research objects.Field investigation and specimen collection were carried out in the study area.In the late stage,the related data such as the number of leafhoppers and molecular sequencing were obtained through laboratory analysis.The community composition,species diversity,community similarity,genetic diversity and the relationship with environmental factors of leafhoppers in large scale(study area)and small scale(sample plots)were preliminarily discussed,and some reasonable environmental monitoring suggestions were put forward.The main findings are as follows:(1)The species composition of leafhoppers under different grades of RD was preliminarily clarified.Temporal and spatial variation law of community species composition was clarified.A total of 74268 leafhopper specimens belonging to 113 genera and 18 subfamilies were collected from the three research areas.Rare subfamilies and rare genera account for a high proportion in the rank elements of the subfamilies and genera of leafhoppers.Dominant subfamilies and common subfamilies,dominant Genera and common genera accounted for less proportion in the rank elements of the subfamilies and genera of leafhoppers.Huajiang study area of Guanling-Zhenfeng(14 subfamilies,73 genera,11593 heads)< Salaxi study area of Bijie(13 subfamilies,80 genera,30468 heads)moderate RD sample plot>slight RD sample plot>potential RD sample plot.The total interpretation rates of the study area are as follows: Huajiang study area of GuanlingZhenfeng>Salaxi study area of Bijie>Karst study area of Shibing.The results showed that the change of temperature and humidity had a great influence on the intensity of RD and Huajiang study area of GuanlingZhenfeng,but had the least influence on the potential RD and Karst study area of Shibing.In terms of spatial variation,the explanatory rate of the first axis and the second axis to the spatial variation of community structure and species diversity of leafhoppers was high.Rock exposure rate and vegetation coverage rate are the main factors.The data of genetic diversity and environmental factors of leafhopper were analyzed.The rock exposure rate,temperature,number of vegetation,humidity and vegetation coverage were the main factors affecting the genetic diversity of leafhoppers in study areas or sample plots.The rock exposure rate,humidity and pressure were positively correlated with ITS-Fst and COI-Fst,negative correlated with haplotype diversity,mean nucleotide difference,nucleotide diversity,number of polymorphic,gene flow.From the scale of sample plot,the average interpretation rate of the first axis between genetic diversity parameters,gene flow and environment were 96.76%,98.93%.From the scale of study area,the interpretation rate of the first axis of the relationship between genetic diversity parameters,gene flow and environment were98.96% and 98.72%.Therefore,the relationship between genetic diversity parameters and environment can be explained more clearly in large scale,and the amount of interpretation between gene flow and environment is similar in both scales.In order to make better use of leafhoppers in response to ecological restoration monitoring of RD,it is suggested that not only the difference of genetic diversity can be used to monitor the restoration effect of RD in a large scale,the species diversity of the leafhopper community can also be monitored or combined.In a small scale,the species diversity of leafhopper community should be used to monitor the restoration effect of RD.