Atmospheric deposition sampling across an urban gradient, using passive resin collectors

One of the "Grand Challenges" for environmental biology is to
increase understanding of human perturbations of biogeochemical cycles (NRC
2001).  One route for these perturbations to be affected is through the
transfer of pollutants from the atmosphere to the biosphere.  As part
of the Ecosystem Response to Material Deposition from the Urban Atmosphere (N.
B. Grimm, PD) study, CAP-LTER scientists are investigating the fate of
anthropogenic organic C (oC) and inorganic nitrogen (iN) deposition and their
effects on ecosystem functioning in unmanaged deserts within and near cities. We
hypothesize that biogeochemical cycling will be qualitatively different in urban
environments due to large inputs of biologically available C and N from the
atmosphere. As part of this project, we will deploy filter banks equipped with
size-selective aerosol inlets to collect particulate oC and iN compounds in the
urban atmosphere. In order to estimate fluxes of these nutrients from the
concentration measurements, we plan to deploy weather stations and to analyze
these data to estimate deposition rates.