Urban Parks Face Climate Risk Due to Soil Biodiversity Loss

Urban parks and residential green spaces may be at greater risk from climate change due to unexpected vulnerabilities in soil biodiversity. A recent study led by an international team of researchers, including Scott Chang, a professor at the University of Alberta, reveals that soil in urban areas is not only more diverse but also more homogenous than that found in natural forests and agricultural lands. The research was published in the journal Nature Cities.

The study analyzed over 200 soil samples from 13 cities across China, each representing different climate regions. Researchers compared microbial communities across four land-use types: forests, farmlands, urban parks, and residential green spaces. The findings indicate that urban parks and residential areas had significantly richer microbial diversity than nearby forests or farmlands. Specifically, the number of species of bacteria, fungi, and protists—tiny organisms living in the soil—was found to be around 14 to 17 percent higher in urban parks and 15 to 20 percent higher in residential areas compared to forest samples.

This increased richness in urban soil biodiversity is attributed to higher soil pH levels, likely resulting from urban management practices such as liming and fertilization. These practices create more favorable conditions for a variety of microbial life. Despite this localized diversity, the study highlighted a concerning trend: urban soil communities across cities exhibited approximately 13 percent more homogeneity compared to adjacent forest soils.

The loss of ecological uniqueness in urban soils could potentially undermine their resilience to environmental stressors, such as extreme weather events. Chang emphasizes the implications of these findings, stating, “There is a risk for those otherwise locally diverse microbial communities to respond to large-scale environmental changes all in a similar way, and as a result, ecosystem resilience could be lowered.”

As urbanization continues to expand, the study raises important questions about the long-term sustainability of urban ecosystems. The findings suggest that efforts to manage urban green spaces must consider not only the diversity of species present but also their ecological uniqueness. A deeper understanding of how urban environments impact microbial communities can guide future urban planning and management strategies to enhance ecological resilience in the face of climate change.