上海市人工林土壤理化性质与群落特征的相关性

人工林是城市具生命绿色基础设施的重要组成部分，土壤是人工林健康可持续发展的基础。在上海市域范围内选取5种主要人工林群落类型样地34个，分层采集0~100 cm土壤剖面样品，对人工林土壤理化性质与植物群落特征的相关性进行了研究。结果表明:①上海市人工林土壤容重偏高（1.07~1.67 g·cm-3），土壤pH 5.7~8.3，土壤电导率（EC）为0.03~0.40 mS·cm-1，碱解氮（5.4~183.4 mg·kg-1），有效磷（1.4~80.5 mg·kg-1）和有机质（3.33~42.88 g·kg-1）相对匮乏；土壤pH值、碱解氮和有机质随土层加深表现出一定的变化规律，并在不同土层间差异显著；土壤容重、有效磷和EC在各土层间无显著变化规律。②有机质分别与土壤容重、pH值、碱解氮和有效磷在0~30 cm土层显著相关（P＜0.05）；碱解氮和pH值在0~30 cm显著相关（P＜0.05）。③0~10 cm土层，群落郁闭度与土壤EC显著负相关（P＜0.05），碱解氮和有机质与样地乔木平均胸径和草本层盖度显著正相关（P＜0.05）。受城市化和人类活动影响，在对人工林进行管理时，应考虑城市人工林的复杂性与差异性，针对不同类型林地制定相应的个性化管理措施，促进人工林长效健康可持续发展。

Soil physical and chemical properties and effects of plant community characteristics in forest plantations of Shanghai City

Forest plantations are an important component of urban green infrastructure with soil being fundamental for healthy and sustainable development of forest plantations. To understand the soil physical and chemical properties and their connection to plant community characteristics, thirty four 25 m×25 m plots from five main forest plantations types in Shanghai were selected. Each soil sample was a mixture of three sub-samples taken from each layers in 1 m×1 m×1 m soil profile, and plant community characteristics were surveyed at the same time. One-way analysis of variance was applied to test the differences of soil properties (SPSS ver. 23). Pearson's correlation analysis was performed to assess the relationships between soil properties and community characteristics with software R, ver. 3.2.0. Results showed that (1) soil bulk density was between 1.07-1.67 g·cm-3. Most of the soils were alkaline to weakly acidic (soil pH range of 5.7-8.3). The soil electric conductivity range of 0.03-0.40 mS·cm-1, and available N range of 5.4-183.4 mg·kg-1, available P range of 1.4-80.5 mg·kg-1, and organic matter range of 3.33-42.88 g·kg-1. Soil pH, available N, and organic matter presented regular dynamics and significant differences between different soil layers (P < 0.05). Soil bulk density, available P, and electric conductivity had no large change between different soil layers. (2) At 0-30 cm soil depth, organic matter was significant related to soil bulk density, soil pH, available N, and available P (P < 0.05). Available N and pH were also significant related (P < 0.05). (3) At 0-10 cm soil layers, tree canopy density had significant negative relationship with soil electric conductivity (P < 0.05); available N significant had positive relationship with diameter at breast high and herbaceous layer cover (P < 0.01); organic matter had significant positive relationship with diameter at breast high (P < 0.05) and herbaceous layer cover (P < 0.01). In conclusion, with rapid urbanization and intensive human activities, the complexity and disparity of forest plantations types should be considered when making specific management measures, rather than simply being based on previous study results, thereby promoting a healthy and sustainable development of forest plantations.