ASSESSING BLACK CARBON IN NYC'S URBAN SOILS

Black Carbon (BC) 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. Black carbon is a product of incomplete combustion of biomass materials, as well as fossil fuels. It is hypothesized that there will be higher levels of BC in urban soil. The sources could be atmospheric deposition and human transported material, such as coal. It is important to understand the levels and distribution of BC in urban areas, 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 less disturbed areas have less BC, whereas areas with more human influence contain more BC. Various soil types from across NYC were sampled and measured for BC content. The method used to quantify BC was a modified version of the chemo-thermal oxidation method at 375 ºC (CTO 375). Preliminary results found much higher levels of BC in soils formed in human transported materials, such as coal ash.