Relationship Between Vegetation Structure And Pollinator Diversity In Urban Green Space

Pollinators are an important part of urban biodiversity,and their changes in community number and species composition can directly or indirectly reflect the dynamic balance of urban ecosystem,which plays an important role in maintaining urban biodiversity.With the acceleration of urbanization,pollinators face problems such as the reduction of nectar sources and the damage of habitat and nesting environment,and their diversity is at risk of decline.Based on this,this paper takes Hefei Huancheng Park as the research area,selects7 typical green Spaces with different vegetation structures based on ecological unit mapping classification system,and carries out data survey on vegetation structure,environmental characteristics and pollinators.On the basis of clarifying the vegetation structure of different types of green Spaces,the differences of pollinator community characteristics in green Spaces with different vegetation structures were analyzed by combining the relevant data of vegetation factors and environmental factors.Urban pollinator richness,abundance,Simpson diversity index,Pielou evenness index and density were used as indicators.Pearson correlation analysis,stepwise regression analysis and other methods were used to explore the effects of vegetation structure and environmental characteristics on pollinator communities,and to provide theoretical basis for the planning.This paper provides a theoretical basis for the planning,construction and management of urban green space to strengthen the protection of urban pollinator diversity.The results are as follows:(1)21 pieces of sample were measured trees 733 plants,shrubs,292 plants and shrubs hedgerow 269 m2,53 genera and 110 species,belonging to 37 families used the highest number of ba was followed by Palm,Lagerstroemia indica,Photinia serrulata,Osmanthus,Cinnamomum camphora,Lilac,Ligustrum lucidum,Pittosporum,Pomegranate,Prunus lannesiana,herbal application times higher for the Radix ophiopogoni,Zoysia japonica,White clover.There was no significant difference in plant richness and plant diversity among the seven typical vegetation structures(p=0.999,p=0.150).There were significant differences in nectar source plant richness and flowering abundance(p=0.012,p=0.003).(2)In terms of sample plot selection,the area distribution range of the sample plot is1515-2410m~2,and the perimeter changes between 145-246m.There are no significant differences in the surrounding land type,location environment,human interference and hard pavement coverage of 21 sample plots with 7 vegetation structures.In the analysis of variance of relevant factors of green space environmental characteristics of two different vegetation structures,there are significant differences in the environmental characteristics of some vegetation structure samples.(3)A total of 7898 pollinators in 32 families of 6 orders were recorded in 21 plots of 7vegetation structures.According to the definition of dominant species,Apidae(12.73%),Lycaenidae(10.75%)and Muscidae(10.19%)are the absolute dominant families of urban pollinators.The richness,abundance,diversity and density of pollinators in green space with different vegetation structures have extremely significant differences(P=0),the species evenness of pollinators has no significant difference(P=0.64),and the Jaccard index is between 0.32-0.93.The species of pollinators in green space with different structure types are moderately similar.Among them,the abundance,abundance,diversity and evenness of pollinators in semi open low shrub,semi closed multi double-layer broad-leaved forest and semi open green space dominated by no mowing are higher,while the closed single-layer broad-leaved forest is the lowest.(4)The results showed that urban green Spaces with different vegetation structures and environmental characteristics would have different impacts on the diversity of pollinators,among which semi-open green Spaces without pruning,semi-open shrub and semi-closed multi-double-layer broad-leaved forest were the high-quality habitats for pollinators.The vegetation community factors were classified as tree and shrub coverage,flowering abundance of nectar source plants,shrub richness and herb richness.The environmental characteristics that affected the diversity of pollinators mainly included plot perimeter,percentage of connection between plot perimeter and water area,and location environment.Stepwise regression analysis showed that average tree height and DBH of trees,flowering abundance of nectar source plants,shrub richness,herb richness,plot circumference and plot location were the important factors influencing the community characteristics of pollinators,and the regression equation for predicting the diversity,richness and abundance of pollinators was obtained.Based on the above results,in order to increase the diversity of urban pollinators,urban green Spaces should increase the three types of planting structures:semi-open shrub,semi-open grass and semi-closed multi-double-layer broad-leaved forest.The core habitat of urban green space should be far away from main urban roads as far as possible,and large area of pure forest with single vertical structure should be avoided in plant design.It is suggested to improve the diversity of shrubs and herbs and increase the richness of nectar source plants on the basis of controlling the coverage rate of trees and shrubs.At the same time,the frequent clipping of grassland was appropriately reduced,and the spontaneous growth of native herbs was utilized to meet the habitat needs of different pollinator communities.