Diversity of riparian macrofungi along an urban-suburban gradient

Background/Question/Methods

Macrofungi are a diverse and ecologically important community in many habitats, and several species are currently threatened by habitat loss due to development, logging, fires, invasive species and climate change. Few studies have been performed on the relationship between fungal diversity and urbanization. We studied the diversity of macrofungi along the Bronx River, New York City’s only freshwater stream, from its headwaters to its mouth. We predicted that the degree of urbanization at each of 18 sites would affect macrofungal diversity and abundance. Based on studies of other taxa such as plants, macroinvertebrates, birds, and mammals, we expected that highly human-altered habitats would result in decreased diversity but perhaps increased abundance of a few species, compared to less human-altered natural areas.

Results/Conclusions

Preliminary results indicate that the urban to suburban gradient has only modest effects on the abundance and diversity of macrofungi along the Bronx River. Contrary to results among other organisms such as birds and mammals, some of the sites of highest urbanization contained the highest diversity and abundance of specimens. The species most well represented include Calvatia gigantea, Laetiporus sulphureus, Tremella mesenterica and Lycogala epidendrum. These results indicate a relationship between macrofungal diversity and local habitat factors, but not necessarily with the degree of urbanization in particular.