Study On Species Diversity And Optimization Strateay Of Trees In Zhengzhou Park

In this paper,the trees of 10 representative parks in the green space of Zhengzhou as the research object.The time-sensitive Digital orthophoto map by UAV(unmanned aerial vehicle)were used to set grid of 50*50m along the south,north directions of each park.Lays out 684 survey plots in the park area,and basically finds out the current status and spatial distribution characteristics of the trees in Zhengzhou city parks.On this basis,in prder to further reveal the characteristics and driving factors of trees diversity in urban park,at the sametime,study on the species composition,important value,diversity index,and the relationship between each diversity index and diversity factores.The investigation and the analysis results are as follows:1.The survey statistics show that there are 131 arbor species(variety)in the survey plots of Zhengzhou city park,belonging to 49 families and 87genera,including 33 evergreen tree species,98 deciduous tree species,98 native tree species,and 33 non-native tree species.It is mainly composed by common genera in the north,such as Rosaceae,Oleaceae,Leguminosae,Sapindaceae,Pinaceae,Ulmaceae and so on.At present,the average DBH of the trees in the park is 17.76cm.It is mainly concentrated at 10-15cm,and there is still a large space for growth.Among the 10 parks studies,the highest planting density was Lvgu park,which was 0.075,and the lowest was People’s park,which was only 0.017.2.There are abundant tree species in the park of Zhengzhou city,and there are certain differences in species richness between different habitat types.The overall performance is:Woodland(WL)>Roadside(RS)>Square edge(SE)>Between road and park boundary(R-PB)>Between road and building(R-B)>Between road and water(R-W)>Park boundary(PB)>Between road and square(R-S).In terms of spatial pattern,woodland and roadside are the habitat types with the largest number of samples,and they also contain the largest number of species,with 100 and 83 species,respectively.The tree species of Rosaceae are higher than those of other families in various habitats in the park.The spacies of Oleaceae,Pinaceae,Magnoliaceae,Cupressaceae,Leguminosae,are distributed in all habitats.The tree planting density between road and park boundary(R-PB)was the highest,at 0.054,and the planting density at the square edge(SE)was the lowest,at 0.018.3.The Margalef richness index of the 10 parks surveyed has an average value of 7.20,of which the highest value is 10.40 and the lowest value is 2.81;the Shannon-Wiener diversity index has an average value of 3.11,of which the highest value is 3.61 and the lowest value is 2.23;Simpson index The mean value is 0.94,with the highest value being 0.96 and the lowest value being 0.87;the average value of Pielou evenness index is 0.81,among which the highest value is 0.9 and the lowest value is 0.62.The average value of the Shannon-Wiener diversity index for 8 different habitats is 3.20,roadside(RS)the highest index value is 3.65,the lowest between road and square(R-S)index value is 2.39;the average value of Simpson Diversity Index is 0.93,and between road and building(R-B)is 0.95,between road and square(R-S)the minimum value is 0.89;The average value of Pielou’s uniformity index is 0.69.The maximum value between road and building(R-B)is 0.86,and the minimum value between road and square(R-S)is 0.48.In all habitats,the diversity of woodland(WL)and roadside(RS)is relatively high,and the diversity index between road and square(R-S)is relatively low.4.Regression analysis between the diversity index and driving factors of each park shows that:with the construction of urban parks,the diversity index of park trees in Zhengzhou city shows a decreasing trend year by year,of which Margalef richness index The trend of decreasing time gradient is the most obvious,R2 is 0.6569;as the urban gradient gradually increases from the inside out,each biodiversity index shows a decreasing trend,of which the Margalef richness index is most closely related to the urban gradient,R2 is 0.7501;The diversity index of comprehensive parks,street green spaces,special parks,and country parks shows a decreasing trend;with the increase of the park area,the Margalef richness index,Shannon-Wiener diversity index,Pielou evenness index in the park The values are gradually increasing.5.Put forward suggestions for enriching the species diversity of greenery trees in the park:(1)Strengthen popular science education for urban biodiversity protection and enhance people’s awareness of species diversity protection.(2)Make full use of the rich plant resources in Henan Province,enrich the urban landscape,beautify the urban environment,and at the same time play a role in protecting the diversity of native tree species.(3)Actively introduce exotic arbor species to enrich the species diversity of tree species in Zhengzhou Park and at the same time create a rich plant landscape.(4)Optimize the park plant configuration.In the process of plant configuration in the park,overcoming the shortcomings of blindness and randomness,in-depth discussion and thinking from the perspective of enriching urban plants and protecting urban biodiversity,urban biodiversity protection will be greatly improved.(5)Construct park green space with a certain scale and distribution area to provide a guarantee for the formation of stable plant communities.