You are here:
APPLICATION OF STABLE ISOTOPE TECHNIQUES TO AIR POLLUTION RESEARCH
Citation:
Gregg, J W., D M. Olszyk, AND E. A. Hobbie. APPLICATION OF STABLE ISOTOPE TECHNIQUES TO AIR POLLUTION RESEARCH. Presented at 5th International Symposium on responses of Plant Metabolism to Air Pollution and Global Change, Pulawy, Poland, November 1-4, 2001.
Description:
Stable isotope techniques provide a robust, yet under-utilized tool for examining pollutant effects on plant growth and ecosystem function. Here, we survey a range of mixing model, physiological and system level applications for documenting pollutant effects. Mixing model examples include determining pollutant sources via d108Pb, d34S, and d15NO2 signatures. Physiological examples include documentation of variation in: leaf internal [CO2] (Ci) due to differences in water-use-efficiency; d13Cair , due to ambient [CO2]; the ratio of PEP carboxylase : Rubisco activity due to ozone exposure; and d18O due to stomatal conductance. System-level examples review the array of applications employed in the US EPA ?closed' chamber, elevated [CO2] mesocosms. These applications include: use of d13C and d15N to assess foliar and root C and N turnover; use of d13Ccorn to correct for d13Cair for comparisons of Ci and PEP carboxylase : Rubisco activity in C3 vegetation; and use of a dual isotope (d13CO2 and dC18O2), three-ended mixing model to determine the relative proportion of root : SOM : litter respiration for soil CO2 efflux. The goal of this overview is to incite discussion of potential future applications.