The relationship between metal contamination, ectomycorrhizal diversity and plant biomass in an urban brownfield

Background/Question/Methods

Metal contamination of soil can be detrimental to plant health and restrict diversity in plant communities. The partial removal of railroad ties from Liberty State Park in New Jersey, along with dumping, polluted the soil and caused a build-up of As, Cr, Cu and Zn. The plant community was able to adapt to the contamination and is now dominated by Betula populifolia and Populus spp. There is currently only limited knowledge of the belowground ectomycorrhizal fungi (EMF) diversity in the park and how it is affecting plant community structure. EMF are able to help plant communities become more metal tolerant by limiting the translocation of metals into plant tissue. This study will examine the relationship between the level of EMF diversity and the total biomass and complexity of plant community structure in metal contaminated sites. Four sites at Liberty State Park were chosen to be sampled based on a metal concentration gradient. The sites range from low contamination of metals to very high. Soil cores were taken at five locations within each site, and the mycorrhizal community of each was examined for species richness and diversity.

Results/Conclusions

Twenty-two species were found in total, varying in relative abundance. The four sites were ranked in regards to moisture content. Two of the sites were categorized as having low moisture, and two were high moisture. The preliminary data collected in this study was analyzed using Principle Component Analysis (PCA) and MANOVA statistics to determine if there is a relationship between metal load and EMF diversity and community composition, moisture and EMF diversity, and EMF diversity and plant biomass. There was a significant relationship found between soil moisture and plant biomass under high metal load conditions. Under low metal load conditions there was no relationship between moisture and plant biomass. There was a significant difference in EMF community structure according to the site along the metal gradient.  The data will be further examined to see if there are any relationships between EMF diversity and moisture. This data will provide further insight into the relationship of plant communities, their symbiotic EMF and metal contamination.