| Urban biodiversity is currently the focus and core of related disciplines.In order to explore the spatial distribution of plant diversity in urban green space,this paper takes the urban area of the Xuzhou bypass highway as the research object.Firstly,according to the landscape gradient characteristics of the study area,15 samples are divided and four directions are intercepted in the northwest,northeast,southeast and southwest,and82 samples are set up.A typical plot method was applied to investigate the community of each plot.Species richness index(S),Shannon-Wiener index(H')and Pielou index(E)was used to measure the species diversity of plant communities,and the spatial distribution characteristics of urban green space species diversity were analyzed by using Moran's I index and semi variant function.Based on the Landsat TM remote sensing image data of the study area in 2015,using Erdas and GIS software,the research area was divided into seven landscape types: building land,woodland,farmland,water area,road,grassland and unused land,and using Fragstats software to analyze the landscape characteristics of the study area.The spatial analysis function of GIS is applied,and the corresponding buffer is tailored to each plot.And 19 landscape indices were extracted by Fragstats software.Using Spearman rank correlation analysis and RDA analysis of Canoco software,we studied plant diversity's response to landscape patterns.The results of the study show that:(1)There are 338 species of plant community in Xuzhou urban green plant community,belonging to 86 families and 251 genera.Among them,45 families,80 genera and 88 species of artificial plants,79 families,233 genera and 304 species of wild species,and the diversity of species composition at different levels of the plant communities,the larger plant species in the trees and shrubs,and the diversity of the urban green plants.The research should focus on the herb layer and the wild species of herbaceous layer.The proportion of evergreen trees in urban green space in Xuzhou issmall,evergreen shrubs and evergreen herbs have a large proportion of planting.The species of urban green space are mainly deciduous and evergreen,and the urban green plant flora and geographical components are complex,and the flora is temperate.The dominant area is consistent with the geographical location and climatic conditions of the warm temperate zone in the study area.(2)The richness of the community,herbaceous layer and herbaceous layer of wild plants increased along the city center,and the Shannon-Wiener index fluctuated along the city center to the suburbs,while the Shannon-Wiener index of the herbaceous and herbaceous species increased,near the downtown area,the community and the herbaceous field.The changes in the Shannon-Wiener index of the plants were smaller,the greater the fluctuation in the suburban direction,the decrease of the Pielou index in the community,and the increase of the Pielou index of the wild species in the herb layer and the herb layer;the plant diversity of the community,herbaceous and herbaceous species was related to the whole Bureau space,and there was spatial aggregation.The accumulation is not strong;the plant communities of urban green plant richness in space are mainly distributed in the east of the city.The Shannon-Wiener index and Pielou index of urban green space are mainly distributed in the southern side of the city,and the space of plant diversity in the eastern region is in space.The variation of the variation is greater than that in the western region,and the spatial variability of the richness shows that the direction of the northwest to the southeast is greater than the northeast and the south-west,and the spatial variation of the plant uniformity in the southeast is greater than that of the other three regions.(3)The total area of the study area is 52765.54 hectares and the total number of patches is 139962.The complexity of the landscape boundary is general,it is disturbed by the outside,the degree of agglomeration is high,the connectivity is high,the fragmentation of patches is small,the degree of fragmentation is high,the land use type is rich and rich,and the patch gathering process from the city center to the suburb is very rich.The degree of degree is reduced,the degree of patch dispersion is increased,the area of the buildings is fluctuating,the landscape fragmentation in the southwest part is the most obvious,the adjacent area of the northwest region and the patch type is larger,the accumulation degree of the northeast area is higher,the land use type is the most abundant in the northwest area,the grassland area in the northwest area is thelargest and the different regional buildings are built.The area of land is basically the same,and the urban development is more balanced.(4)The higher the degree of fragmentation of buildings,the urban green space plants will be richer;the larger the grassland area,the higher the degree of aggregation,the higher the fragmentation degree of grassland,and the number of urban green plant species will be lower;the lower the degree of fragmentation of farmland land types,the species of urban green space is more abundant;the smaller the proportion of urban land,the level of urban plant diversity is higher;The effect of RDA sorting between urban green plant diversity and landscape pattern index is better.Increasing the area of green patches and increasing the degree of aggregation between green spaces are beneficial to improve the diversity of wild herbaceous plants,and should give priority to the protection of urban green space with larger area,large patch area of green space or green space.The protection benefit of green space is the highest when the distance is closer. |
PDF Full Text Request