Soil Microbial Diversity in Urban Environments: Preliminary Results from New York City Soils.

It is increasingly important to characterize and understand the composition and dynamics of urban soils as the U.S. population progressively concentrates in these areas. A key component of these soils are the microbial communities that are integral players in mechanisms of soil change and the rate at which these changes take place. Soil microbial communities respond to alterations in physical and chemical processes that soils continually encounter as a result of both natural and anthropogenic events. In this ongoing project, we are collecting coupled dynamic soil properties (DSP) and microbial community metagenomic data from 48 sites in New York City (NYC). We are determining bacterial and fungal diversity and relative species abundance, examining how these species change over time, and how they correlate with the surrounding environment. Sampled sites consist of both native and human-altered soils and are being excavated in warm and cold seasons. Soil samples are taken from each horizon and total DNA is extracted. Metagenomic data are obtained by Illumina sequencing of DNA samples, targeting the 16S rRNA gene V4 variable region for bacteria and ITS for fungi. Here we present preliminary data related to the microbial communities present in Staten Island Greenbelt and Inwood Hill Parks. Our results show a higher microbial diversity on superficial soil layers, with proteobacteria as the dominant component, and decreasing diversity as depth increases, with bacteroidetes becoming more dominant. Microbial diversity seems to be comparable across sampling sites on the surface, but the more variation is seen with increased depth. These initial findings will allow us to make comparisons to existing soil microbial community datasets from other environments to determine how urban soils differ from agricultural soils or soils minimally disturbed by human activity.