Using Icelandic CO2 springs to understand the long-term effects of elevated atmospheric CO2

Abstract

SUMMARY The CO 2 -emitting mineral springs of Iceland have been surveyed and assessed for their use in understanding the potential effects of elevated atmospheric CO 2 on northern ecosystems. One spring near Olafsvik is described in detail here. This CO 2 spring emits CO 2 in such a way that the surrounding vegetation is exposed to mean CO 2 concentrations which are consistent with those predicted for the next century. Results from carbon isotope analyses show that Nardus stricta plants growing near this CO 2 spring are exposed to mean CO 2 concentrations of approximately 880, 650 and 430 ppm, depending on their location relative to the CO 2 vent. Maps and tables are provided to show how the concentration of CO 2 measured in the vegetation varies over time on calm and windy days. A list of the species growing around the Olafsvik CO 2 spring is included and the research potential of CO 2 springs is discussed at length. The use of natural CO 2 springs as surrogates for elevated CO 2 experiments appears highly promising. INTRODUCTION The concentration of carbon dioxide in the atmosphere is increasing due to the burning of fossil fuels and deforestation. How plants evolve in response to elevated CO 2 and global climate change will ultimately affect many of the important responses of the biosphere including primary productivity, trace gas flux, and vegetation boundaries.