Delta13C values of grasses as a novel indicator of pollution by fossil-fuel-derived greenhouse gas CO2 in urban areas.
A novel fossil fuel pollution indicator based on the 13C/12C isotopic composition of plants has been designed. This bioindicator is a promising tool for future mapping of the sequestration of fossil fuel CO2 into urban vegetation. Theoretically, plants growing in fossil-fuel-CO2-contaminated areas, such as major cities, industrial centers, and highway borders, should assimilate a mixture of global atmospheric CO2 of delta13C value of -8.02 per thousand and of fossil fuel CO2 of average delta13C value of -27.28 per thousand. This isotopic difference should, thus, be recorded in plant carbon. Indeed, this study reveals that grasses growing near a major highway in Paris, France, have strikingly depleted delta13C values, averaging at -35.08 per thousand, versus rural grasses that show an average delta13C value of -30.59 per thousand. A simple mixing model was used to calculate the contributions of fossil-fuel-derived CO2 to the plant tissue. Calculation based on contaminated and noncontaminated isotopic end members shows that urban grasses assimilate up to 29.1% of fossil-fuel-CO2-derived carbon in their tissues. The 13C isotopic composition of grasses thus represents a promising new tool for the study of the impact of fossil fuel CO2 in major cities.
Lichtfouse
Eric
E
Microbiologie et Géochimie des Sols, Centre des Sciences de la Terre, INRA-Université de Bourgogne, 6 Boulevard Gabriel, 21000 Dijon, France. Eric.Lichtfouse@u-bourgogne.fr
Lichtfouse
Michel
M
Jaffrézic
Anne
A
D002245:Carbon Dioxide / Q000032:analysis*; D002247:Carbon Isotopes / Q000032:analysis; D002947:Cities; D004784:Environmental Monitoring; D005579:Fossil Fuels; D017752:Greenhouse Effect; D007221:Industry; D008962:Models, Theoretical; D006109:Poaceae / Q000737:chemistry; D001335:Vehicle Emissions / Q000032:analysis
D002247:Carbon Isotopes; D005579:Fossil Fuels; D001335:Vehicle Emissions; D002245:Carbon Dioxide