Fungal community composition of urban riparian soils

Background/Question/Methods

The soils and sediments of urban riparian corridors are unique, holding great potential to prevent downstream eutrophication by remediating nutrients. Fungi in soils and sediments are a crucial aspect of urban riparian ecosystems because they support nutrient uptake by plants via mycorrhizal associations. Our study concentrates on the riparian corridor of the Toms River, which spills into the Barnegat Bay in New Jersey. The soils in this area are often flooded, which can lead to anaerobic conditions. The goal of our study was to see how this affects their fungal community composition. In our study, we sampled soils from four different sites along the Toms River; each site had three zones: riparian, wetland, and upland. We used mini-cores to take soil samples along transects in each zone. Then we extracted DNA from the soil, amplified any fungal DNA using ITS primers, and characterized the fungal communities using terminal restriction fragment length polymorphism (TRFLP). Finally, we compared the fungal communities to previously studied bacterial communities from the same soil cores.

Results/Conclusions

Comparisons with corresponding bacterial communities showed less fungal DNA than bacterial DNA. The anoxic environment created by frequent flooding, together with above ground plant community composition, could explain this. In addition, early results show that fungal communities vary among the four sites, as well as between riparian, wetland, and upland zones. Both riparian and wetland soils were flooded at the time of sampling, but not all sites were equally inundated. This could explain the differences between soil communities in the three zones. Our research provides a preliminary indication of how urban riparian fungal communities correspond with bacterial communities, as well as how flooding influences them. Thus, it could be utilized, along with further research, in remediation plans for urban riparian ecosystems.