【目的】颐和园是著名的皇家园林及世界文化遗产,监测评价其土壤质量,为提升颐和园管理水平,实现世界文化遗产地及其生态环境的科学保护与管理提供参考。【方法】采集颐和园代表性植被覆盖区域的表层(0~20 cm)土壤样品,检测土壤容重、pH、电导率、有机质、全氮、全磷、全钾、碱解氮、有效磷、速效钾含量和细菌Shannon多样性指数共11项评价指标,进行主成分分析筛选建立最小数据集,利用隶属函数值及权重赋值法进行土壤质量指数(soil quality index,SQI)计算,通过对全数据集及最小数据集的土壤质量指数进行拟合分析,对不同植被覆盖区的土壤肥力质量进行分析和评价。【结果】最终进入最小数据集的指标为全磷含量、电导率、容重和Shannon多样性指数4个指标,全量数据集和最小数据集分别计算的土壤质量指数之间存在显著正相关关系,R²为0.877。颐和园土壤质量指数(SQI)分3个等级,牡丹种植区的土壤质量较好(SQI≥0.80),落叶阔叶林区、宿根花卉区和野生灌草丛区土壤质量属于中等(0.40≤SQI<0.80),践踏草坪区和针阔叶混交林区土壤质量较差(0.20<SQI<0.40)。园区土壤总体呈现中性至碱性(pH为6.83~8.71),有机质含量普遍低(均值在8.83~17.06 g/kg)。速效磷空间分布极不平衡,变异系数为161.55%,76.00%的样点处于极度匮乏状态。【结论】人为干扰对颐和园土壤质量产生显著影响,牡丹种植区因施用有机肥,土壤质量指数高,其他区域土壤质量中等偏下。全园土壤有机质含量除牡丹种植区外普遍含量较低,有效态氮、磷空间分布不平衡,建议通过保留枯枝落叶、合理施用有机肥及磷肥等措施,改善土壤质量。

【Objective】As a famous royal garden and world cultural heritage site, monitoring and evaluating the soil quality of the Summer Palace is of great significance for maintaining and protecting the health and safety of the park ecosystem.【Method】In this study, soil surface (0-20 cm) samples from a representative vegetation coverage area in the Summer Palace were collected, and 11 evaluation indices: soil bulk density, pH, electrical conductivity, the content of the soil organic matter, total nitrogen, total phosphorus, total potassium, alkali-hydrolyzable nitrogen, available phosphorus, available potassium, and bacterial diversity were measured. The minimum data set was established using a principal component analysis, and the soil quality index was calculated using the membership function value and weight assignment method. The soil fertility quality of different vegetation coverage areas was analyzed and evaluated through a linear correlation analysis of the soil quality index of the total and minimum data sets.【Result】Using the principal component analysis method, the indices finally entered the minimum data set were total phosphorus content, electrical conductivity, bulk density, and the Shannon index. There was a significant positive correlation between the soil quality index calculated using the total and minimum data sets, and R² was 0.877. The soil quality of the Summer Palace was divided into three levels: the soil quality of peony planting land was good (SQI≥0.80); the soil quality of deciduous broad-leaved forest, perennial flower land, and wild shrub and grass clusters was medium (0.40≤SQI<0.80); and the soil quality of trampled lawn and mixed conifer-broad-leaved forest was poor (0.20<SQI<0.40). The soil in the park was generally neutral to alkaline (pH 6.83 and 8.71), and the organic matter content was generally low (the average value was between 8.83 and 17.06 g/kg). The spatial distribution of available phosphorus was extremely unbalanced, with a coefficient of variation of 161.55%, and 76.00% of the samples were extremely deficient.【Conclusion】Human disturbance had a significant impact on the soil quality of the Summer Palace. Owing to the application of chemical fertilizers, the soil quality index in the peony planting land was high, and the soil quality in other areas was medium to low. The soil organic matter content in the park was low, and the spatial distribution of alkali-hydrolyzable nitrogen and available phosphorus was unbalanced. It is suggested that soil quality can be improved by retaining litter and applying organic and phosphorus fertilizers.