上海城市绿地土壤pH分布特征及影响因素

Distribution characteristics and influencing factors of soil pH in Shanghai urban green space

基于上海市中心城区典型绿地土壤571个采样数据,分析了3种类型绿地土壤pH的分布特征,并结合土壤理化性质、地上植被类型和绿地建成年限对绿地土壤pH的影响因素进行了探讨。结果表明:上海城市绿地土壤pH平均值为8.20,属碱性土壤,广场绿地土壤pH显著高于公园绿地土壤和道路附属绿地土壤,且不同行政区域土壤pH具有显著差异。在土壤剖面中,随着土壤深度的增加,土壤pH逐渐增加,表层0—20 cm土壤pH显著低于40—90 cm土壤。上海绿地土壤pH与土壤电导率、有机质含量、水解性氮含量、有效磷含量和速效钾含量均呈负相关,表明绿地土壤肥力越高,土壤pH越低。土壤质地对上海城市绿地土壤pH分布无显著影响,但土壤pH与土壤容重呈显著正相关,与土壤非毛管孔隙度呈显著负相关。地上植被类型显著影响绿地土壤pH,草被群落土壤pH显著高于乔灌群落。随着绿地建成年限的延长,土壤pH有降低趋势,但与新建绿地相比,绿地建成30年后土壤pH才会表现出显著差异。本研究可为上海城市绿地土壤养护管理措施的优化以及助力上海城市绿地土壤质量提升提供指导。

Based on 571 sampling data of typical green space soils in the central urban area of Shanghai,the distribution characteristics of soil pH in 3 types of green space were analyzed,and the factors affecting soil pH in green space were discussed in combination with soil physicochemical properties,aboveground vegetation types,and green space construction years.The results showed that the average pH value of urban green space soil in Shanghai was 8.20,belonging to alkaline soil.The pH value of square green space soil was significantly higher than that of park green space soil and road auxiliary green space soil,and there were significant differences in soil pH among different administrative districts.In the soil profile,with the increase of soil depth,the soil pH gradually increased,and the pH of 0—20 cm soil in the surface layer was significantly lower than that of 40—90 cm soil.Green space soil pH was negatively correlated with soil conductivity,organic matter content,hydrolysable nitrogen content,available phosphorus content,and available potassium content,indicating that the higher the fertility of green space soil,the lower the soil pH.Soil texture had no significant impact on soil pH distribution in Shanghai urban green space,but soil pH was significantly positively correlated with soil bulk density,and significantly negatively correlated with soil non capillary porosity.The type of aboveground vegetation significantly affected the soil pH of green space,and the soil pH of the grass cover community was significantly higher than that of the tree shrub community.With the extension of the green space construction period,the soil pH had a downward trend,but compared to the newly built green space,the soil pH only showed significant difference after 30 years of green space construction.This study could provide certain guidance for the optimization of soil conservation and management measures for urban green spaces in Shanghai,and help to improve the soil quality of urban green spaces in Shanghai.