ASSESSING BLACK CARBON IN NYC’S URBAN SOILS

Black carbon (BC) is a product of incomplete combustion of biomass materials, as well as fossil fuels. It is hypothesized that there will be higher levels of Black carbon in urban soil. The sources could be atmospheric deposition, or human transported material, such as coal. It is important to understand the levels and distributions of BC in urban area because BC is potentially a large reservoir of global carbon which has not been understood well in the context of climate change. Black carbon remains in the soil longer than other types of carbon, resulting in net stable storage of carbon in the soil. It is expected that areas less disturbed have less BC, whereas areas with more human influences contain more. Black carbon is one of the dynamic soil properties being studied as part of a collaborative project between the USDA and Brooklyn College. The project focuses on the microbial diversity of NYC urban soils and their relation to dynamic soil properties. Various soil types from across NYC were sampled and measured for BC content. Black carbon was assessed along the soil profiles of Fortress and Siwanoy, as well as taken from the soil series LaGuardia, Mosholu, Rikers and Secaucus. The parent materials to these soil series are coal ash and construction debris, and found in areas of human transported and disturbed materials. Samples from the Mosholu and Rikers soil series formed in coal ash. Samples from the LaGuardia and Secaucus soil series formed in construction debris. Samples were also taken from soil series Charlton, Deerfield, Haledon(Van Cortland Park, Bronx), and Todthill (Corporate Park woods, Staten Island). The method used to quantify BC was a modified version of the chemo-thermal oxidation method at 375 ºC (CTO 375). The preliminary results show that there is more black carbon found in some soils formed in human-altered and tran-sported materials such, as coal ash.

Keywords: Black Carbon, urban soil, soil series, climate change