Composition Of Garden Plants And Effects Of Soil Conditions On Their Growth In Main Street Squares Of Changchun City

As the material basis of plant growth,soil plays a vital role in the effect of urban greening landscape,and indirectly affects the comfort of urban living,environmental quality and people’s quality of life.As a"National Forest City",Changchun has always attached great importance to the development of urban greening.After long-term development,the soil nutrients of main streets,squares and green spaces will be consumed to varying degrees.With the impact of urban construction,the soil components will also change.It is particularly important to meet the requirements of soil physical and chemical conditions for the growth of garden plants in the future.Taking 24 streets and 6 squares in Changchun as the research object,this paper analyzes and evaluates the plant composition diversity,planting frequency,growth state and soil physical and chemical properties;Through SPSS software,the significance of soil physical and chemical properties in different streets,squares and planting locations is analyzed,and the correlation between species diversity,growth status and physicchemical properties of soil is analyzed.The research results are as follows:（1）Within the survey scope of Changchun City,there are 116 species of landscaping plants,belonging to 28 families and 65 genera,of which woody plants account for 85.6%of the total,a total of 99 species.Among woody plants,there are 15coniferous varieties and 84 broad-leaved varieties,including 68arbors and 31 shrubs.（2）The Shannon-Wiener diversity index（H）shows that the street and square of tree layer>shrub layer>herb layer account for 53.3%,and the Simpson diversity index（D）shows that the street and square of tree layer>shrub layer>herb layer account for46.7%.In terms of Pielou evenness index（E）,the tree layer and shrub layer have better unity.（3）Soil physical properties:57.89%of the roads in Changchun have soil bulk density>1.3 g·cm^-3.The soil bulk density is relatively large and the soil compactness is high;In terms of total soil porosity data,42.11%of soil samples are≤50%,57.89%of soil samples are between 50%～60%,and 51.58%of soil water content>18.13%,indicating that the total soil porosity is large and the soil water holding capacity is strong.（4）Soil chemical properties:the average p H value is 8.28,the average conductivity is 107.95 m S·m^-1,which is at a high level,the average content of available nitrogen is27.01mg·kg^-1,which is at a very low level,the average value of available phosphorus is21.28%,which is at a high level,and the average content of available potassium is117.06 mg·kg^-1,which is at a high level.（5）There was a significant negative correlation between the leaf area of plants and soil p H value in the green space of main streets and squares in Changchun（p<0.05）;There was a significant positive correlation between plant leaf width and soil conductivity（p<0.05）,and a significant negative correlation with soil p H value（P<0.01）;There was a significant positive correlation between plant chlorophyll content and soil p H value（p<0.01）.