城市表层土壤对生态健康影响研究述评

Review for the effects of urban topsoil on the ecological health

人地关系是新时代地理学综合研究的核心,而快速发展的城市化促进了人地矛盾的集中体现。同时,土壤圈是地球关键带中最活跃的圈层,在城市环境中成为人-地联系活跃的生态环节。城市表层土壤在区域小尺度水平人-地联系中具有重要意义,但对其生态界面意义还未有专门的论述。虽然现在已有较多的学者研究报道了城市化进程中土壤性质变化、重金属和有机污染等问题,但对其中的源-汇正负反馈效应仍然认识不足。为了城市的可持续发展,各种生态健康评价研究蓬勃开展。其中,土壤动物特有的生物学属性和环境敏感性,使之成为城市环境变化和生态健康风险评价优良的综合性指示因子,然而相关的研究比较缺乏。因此,本文就城市表层土壤对生态健康影响的研究进行了述评。城市表层土壤既是生物的聚居地,又与城市大气、水体存在密切的互作交流关系,对城市人类活动具有积极的正负反馈作用,成为城市人-地联系的关键生态界面。城市化背景下土壤表层生物、理化性质的变化不仅对土壤健康造成威胁,同时也增加了人居健康风险。最后,本文对相关研究进行了展望,提出未来应加强城市表层土壤的生态界面效应研究,在研究方法上要建立长期、多尺度的城市土壤研究计划,以及推进区域城市表层土壤动物生物学、生态学研究等。

Human-land relationship is one of the core fields for the integrated geographical studies in the new era. The rapid urbanization has promoted the outbreak of human-land conflicts. Pedosphere, the most active part in the earth’s critical zones, is the key ecological factor for the active man-land relationships in urban environments. Urban topsoil plays a key role in man-land relationships at regional scale, however, few previous studies discussed its ecological roles. Many studies have reported soil property changes, heavy metal and organic pollutions during urbanization, but the positive or negative feedback effects in the sink-source procession remains unclear. Meanwhile, despite numerous assessments about the urban ecosystem heath, few studies have been done about the responses of soil fauna as an important indicator for urban environmental change and ecological health risks considering its diversity and sensitivity to environmental changes. This study discussed the impacts of urban topsoil on ecological health. Urban topsoil, as a crucial ecological habitat and a crucial interplay with the atmosphere and the water, can make active positive or negative responses to urban anthropogenic activities. Thus, it is a critical interface for man-land interaction in the urban ecosystems. The changes in organisms as well as physical and chemical properties during urbanization, can diversely impact the health of soil and increase the health risks of human beings. Some perspectives on future studies were also proposed in this study, including more concerns on the interface effects of the urban topsoil, long-term, multiscale and systematic research programs, and biological and ecological studies on urban topsoil animals.