Research On The Diversity Of Spontaneous Plant And Its Influencing Factors In Jiangyangfan Ecological Park

With the acceleration of the construction of urban park green space,the phenomenon of landscape modeling and plant homogenization has intensified.The ecological value of natural vegetation in cities is increasingly prominent The public’s acceptance of spontaneous plants has also gradually increased.It is necessary to explore the growth and distribution law of spontaneous plants,apply them to the construction of natural landscape in parks and increase biodiversity.In order to grasp the key factors affecting the growth and distribution of spontaneous plants,this study took Jiangyangfan Ecological Park as the main research object.The composition characteristics and influencing factors of spontaneous plants were studied in detail around temporal and spatial changes.The main conclusions were as follows.(1)The wetland area of Jiangyangfan Ecological Park was investigated for nearly one year.99 species of spontaneous plants were recorded in autumn and winter,100 species in spring and 117 species in summer.In each season,there were no obvious differences in dominant families,species sources,life forms and dominant species of spontaneous plants.Phragmites australis,Hydrocotyle verticillata and Salix rosthornii were the dominant species in each season.The relative importance of Lemna minor in autumn and winter was obviously higher than other herbs.The diversity index was the highest in summer.The highest in autumn and winter for woody plants,and in spring for herbaceous plants.(2)When studying the composition,diversity and distribution pattern of spontaneous plants in different habitat scales.4 types of habitats and 6 types of microhabitats were divided.There were significant differences in species diversity and evenness of spontaneous plants in different habitats and microhabitats(p<0.01).One of the reasons for this phenomenon was the fruit type and seed dispersal mode of spontaneous plants.Herbaceous plants were all clustered.Shrubs and arbors were evenly distributed.When analyzing the influence of environmental factors on the diversity and distribution of spontaneous plants,it was found that water depth and slope direction were the key factors to determine the diversity and distribution pattern of plants in two habitat scales.(3)Jiangyangfan Ecological Park in Hangzhou was compared with the 3 parks in the neighboring Yuhuang Shannan Fund Town Scenic Area.The effects of different park environmental characteristics on the spontaneous plants were discussed.11 species of spontaneous plants were recorded in each park,among which Hydrocotyle sibthorpioides,Alternanthera philoxeroides and Oxalis corniculata were high-frequency species.Perennial herbs account for the highest proportion in the four parks.Native plants account for a large proportion in each park and were all similar.From high to low,the order of the diversity of spontaneous plants was: Jiangyangfan Ecological Park>White Pagoda Park>Eight Diagrams Field Relic Park>Haiyue Waterscape Park.Among the16 park characteristic factors,8 factors had significant impacts on the spontaneous diversity.Among the overall characteristic factors of parks,the park perimeter,actual accessible area,park area and total green area were positively correlated with the diversity of spontaneous plants;Among the characteristic factors of environmental factors,the green space rate and Shannon-Wiener diversity index of cultivated plants were positively correlated,while the number of water bodies,water space rate and green space fragmentation were negatively correlated.Based on multi-season and multi-object field investigation and records,this study analyzed the species diversity and habitat heterogeneity of spontaneous plants,and revealed their growth and distribution laws and their adaptability to the environment.It is expected that spontaneous plants will be reasonably applied to the construction of natural landscape in parks to increase biodiversity.It provided a useful reference for building a sustainable and low-maintenance urban natural landscape and contributed to the improvement and restoration of the urban ecological environment.