Study On Main Green Land's Garden Plant Community Characteristics In Huizhou City Huicheng District

Since the 18th CPC National Congress,General Secretary Xi Jinping has proposed the thought of ecological civilization construction.At the same time,it is proposed that clear streams and green mountains are invaluable assets,and a series of green ecological concepts such as building beautiful China and beautiful garden homes,which have important guiding significance for the construction of China's ecological environment.Urban green space is the "lung" of the city and plays an important role in improving the ecological quality of urban environment building a harmonious living environment,conserving water and soil,increasing biodiversity,and improving air quality.Garden plants is an important part of urban green space.They are producers of urban green space ecosystems and have important impact on maintaining the healthy,stable and harmonious development to urban green space ecosystems.Therefore,there are a series of studies on the community characteristics of garden plants in urban green space which are carried out.There is a great theoretical significance and application value to clarify its species composition,type characteristics,population growth and development laws,and species diversity.There is a sample-plot survey of the garden plants community of three parks and three urban roads in the main green areas of Huicheng District had carried out in this paper.At the same time,in order to clarify the microclimate impact of the main street trees in Lingnan's city on urban roads,the author took Huizhou City as an example to investigate the shading effects of nine common street trees in Huicheng's main roads.The results are as follows:(1)Huizhou urban park green space has abundant plant species and with obvious regional characteristics.The survey results showed that 228 species were recorded in this survey,it belonging to 184 categories and 105 families.Among them,ferns are 5 families,5 categories and 5 species,gymnosperms are 5 families,5 categories and 5 species,and angiosperms are 21 8 species of 95 families and 1 74 categories.Angiosperms accounted for 95.6%of the total number of surveyed plants,while the gymnosperms and ferns totaled less than 5%.The families with more species is the Asteraceae,Leguminosae,Gramineae.Euphorbiaceae and Moraceae and so on 10 families.The genus with more species is the ficus,hibiscus,acacia,duranta,and broussonelia.There are 6 vegetation types in the park green space.These six types are Khaya senegalensis forest(quadrat NO.15).Ficus microcarpa forest(quadrat NO.2),Acacia auriculiformis and Taxodium ascendens forest(quadrat NO.12.1 3),Schima superba and Acacia confuse forest(quadrat NO.14),Aesculus chinensis and Erythrina variegate and Delonix regia forest(quadrat NO.5,16).Ficus microcarpa,Cinnamomum bodinieri and Cinnamomum bodinieri broad-leaved mixed forest(quadrat NO.1 8.20,1 7,10,9,7,1 1,8,6,1 9,1,4.3).The population analysis of park green space indicated that Bauhinia blakeana.Callistemon viminalis and Terminalia neotaliala were a relatively stable population,but the seedlings were cleaned by park-managed workers when they managed the park green space,lacking seedlings with a root stem diameter of 3 cm or less;The Bombax malabaricum population is a declining population;The Ficus microcarpa population is an unregulated population;The individual number of Bischofia javanica and Delonix regia population is relatively small,which is not conducive to the development of the population;The Tabebuia chrysantha is an exotic species introduced in recent years.The survey results showed that this tree is more suitable for the climate characteristics of Huicheng district and the population is a growth type.The park green spaces in Huicheng urban area has a high species richness,and there are 17 quadrats with more than 5 species(including 5 species),accounting for 85%of the total.The calculation results of Shannon-Wiener diversity index(HP)and Simpson diversity index(D)indicated that each quadrat had a basically consistent trend and had a high diversity index value.Comparing in 20 quadrats,the Shannon-Wiener index(HP)of the 2nd.9th,13th,15th,and 18th quadrat is lower than the other quadrat.The main reason is due to the lower number of species in these quadrats.In short,the composition analysis of these families and categories indicated that these plant composition has distinct southern subtropical regional characteristics.The survey uses the floristic classification method of important values and the aggregation grade classification method based on the Euclidean distance of the sample,and the classification results tend to be consistent,while using the statistical software clustering by SPSS analysis is more accurate.The population analysis results showed that a different population has a different growth and development laws.The diversity analysis results showed that the parks in Huicheng district has high species richness and diversity index.The change rule of several diversity index was consistent with each other,this is a stable basics for constructing a stable ecology system.(2)The plant species of the urban street green space in Huicheng urban area is rich,The plant community has obvious regional characteristics.The survey results showed that 174 species were recorded in this survey,belonging to 137 categories and 93 families.Among them,the ferns are 2 families,2 categories and 2 species,the gymnosperms are 1 family,1 category and 1 species,and the angiosperms are 171 species of 90 families and 134 categories.The families with a large number of species are Compositae.Leguminosae,Moraceae,and Apocynaceae,and the category with more species is only Ficus and Cinnamomum.The vegetation types in Huicheng urban street green space is rich.The vegetation types of street plant communities surveyed in Huicheng urban are divided into Jacaranda mimosifolia and Bombax malabaricum forests;Sapindus mukorossi and Elaeocarpus decipiens forests;Delonix regia and Ceiba insignis forests;Dracontomelon duperreanum and Bauhinia blakeana forests;Ficus microcarpa and Delonix regia forests:Washingtonia filifera and Livistona chinensis forests;Jacaranda mimosifolia forests and Khaya senegalensis forests by the month of important value flora classification.It was found that the tree layer of the greenland plant community in Huicheng urban area had rich species richness index and high diversity index through calculating the Shannon-Wiener index(HP),the Simpson index(D),and the Pielou evenness index(Jsw)of the 16 quadrats in the survey street green space,and the average species richness is 7.5,and there is 12 quadrats' the Shannon-Wiener index(HP)is greater than 1.5.The highest index value is 2.480 to quadrat NO.1 In addition,the calculation of the Simpson index(D)indicated that each quadrat has a trend that is basically consistent with the Shannon-Wiener index(HP).Therefore,the distribution of the main dominant families and category indicatedthe characteristics of the southern subtropical nature of the urban street green space plants in Huizhou.The vegetation types are richness,and with more high species diversity for street green land.(3)The street tree experimental results showed that all street trees have a certain shading rate and cooling rate.The Michelia alba tree has the best shading effect.It's shading rate was 95.81 percent The poorer is 61 percent for Roystonea regia and 63 percent for Elaeocarpus apiculatus,and other species are somewhere in between of Michelia alba and Roystonea regia with Elaeocarpus apiculatus.The Ficus microcarpa tree has more higher temperature drop rate,it's cooling rate was 9.83 percent,and it's temperature drop 3.5?.The Elaeocarpus apiculatus has more poorer cooling rate,it's cooling rate only was 1.5 percent,the temperature drop only 0.5?.Combining with the quality of shade and shading effect,the better tree species of shading is the Ficus microcarpa,the poor one is Roystonea regia and Elaeocarpus apiculatus,while the Ormosia pinnata,Khaya senegalensis.Ficus altissima,and Ficus altissima also has good shading effect.In the future,this trees as Ficus microcarpa,Michelia alba,Ormosia pinnata,Khaya senegalensis,Ficus altissima,and Ficus lacor,it will be chosen preferentially as an street trees when it be paid attention to its shade function in the Lingnan's city,but when the landscape characteristic can be paid attention,the trees as Roystonea regia and Elaeocarpus apiculatus can be chosen.