A modular system for research on the influence of elevated atmospheric carbon dioxide on ecosystems.
The free-air fumigation of plants (either single or society) with trace gases (e.g. carbon dioxide) is a very important tool for experimental botany. This specially applies if greenhouses are not suitable for research because the experimental results have to be extrapolated to environmental situations.
Free-air fumigation systems have to keep up a specified concentration of trace gases against the external influence of wind and rain, sometimes this may be for a period of several years. The probed biological system may be altered irreversibly and though invalidate the measured results if there are variations in the concentration of gas, either region- or time-dependent. All those factors increase the requirements towards free-air fumigation systems.