Understanding ectomycorrhizal-tree response to urbanization

Dr. Adriana Corrales, Director of SPUN's Underground Explorers program, is lead author of this research article, which looks at ectomycorrhizal (ECM) populations associated with trees in Bogotá, Colombia.

The study explores the community composition of root-associated fungi of Quercus humboldtii (Fagaceae), a tropical ectomycorrhizal tree species.

Urban landscapes are expanding worldwide, which means that the diversity and structure of ectomycorrhizal communities in urban settings could be affected.In this case, the Andean oak is planted as an urban tree in Bogotá. The authors explain that root-associated fungal communities of this tree differ between those growing in natural and urban settings.

This is important research because it provides insights as to how mycorrhizal fungi and host tree  relationships change  under urbanization pressures.

In this case, the authors found that:

1. Urban trees are important as reservoirs of underground fungal diversity.
2. Urban conditions favor fungal species adapted to more disturbed ecosystems.

Ectomycorrhizal fungi form trading relationships with trees. Trees in most boreal and temperate forests depend on these ectomycorrhizal [hyperlink definition] associations.The way the relationships change under different environmental conditions can tell us how both partners are adapting over time, in this case  largely due to threats such as human encroachment and urbanisation.

Few studies have focused on the structure of fungal communities in urban ecosystems, despite their importance to tree and ecosystem health. Specifically, Quercus forms associations with ECM fungi that contribute to the provide the trees with key nutrients and underpin soil biogeochemical processes. Additionally, urban landscapes are expanding, and increasingly provide habitat for wild species as  more encroachment takes place.

In conclusion, the authors report significant differences in the community composition of fungi present in the roots of rural and urban trees, with rural communities being dominated by Russula and Lactarius and urban communities by Scleroderma, Hydnangium, and Trechispora. These findings suggest a high impact of urban disturbances on ectomycorrhizal fungal communities.