Black carbon and fine root dynamics in forest ecosystems

Project Overview
Project Abstract: 
Fine roots and pyrogenic organic matter (PyOM, e.g. charcoal and soot) are known to be important sources of carbon (C) inputs to forest soils. My research at the UMBS addresses several unknowns regarding: (1) the main factors that control fine root dynamics; (2) PyOM mean residence time, and transport to lower soil depths. In summer 2010, I established a field study in the DIRT plots to investigate the effects of N deposition and litter manipulation on fine root degradation and vertical transport in soil. In this study, I follow the fate of 13C and 15N from applied 13C/15N- enriched Acer rubrum L. roots into soil C and N pools including CO2 efflux, bulk soil and soil leachate. I will also monitor fine root 13C uptake into microbial groups. Additionally, I investigate PyOM dynamics in forest ecosystems by addressing the following questions: (a) What is the turnover time of PyOM in forest soils? (b) How much PyOM material is transported to lower soil depths? (c) How much of the PyOM aerosol deposited at the UMBS is from vegetation fires and fossil fuels burning? To answer these questions I will use benzene polycarboxylic acids to quantify PyOM-derived C in soil horizons collected in 1980 and 2009 at the UMBS fire chronosequence experimental site. In addition, I have determined the amounts of PyOM-derived C (using a thermo-optical carbon analyzer) in atmospheric fine particulates collected in summer 2009 and 2010 at the UV-B monitoring site. I will use molecular markers techniques to quantify the relative contribution of fossil fuel and biomass combustion to PyOM-derived C aerosols.
Investigator Info
Funding agency: 
NSF-IGERT
Years research project active: 
2009 to 2011