Until a few years ago, it was assumed that the relationship between plants and the Earth's climate was relatively minor. Toward that end, scientists collected a wide variety of data from 1993 to 1996, measuring levels of heat and solar radiation, carbon dioxide, water and trace gases. The team's principle responsibility has been to provide calibration and quality control for measurements of thermal and solar radiation, particularly for the part of the light spectrum that drives photosynthesis.
Photosynthesis is the fundamental process whereby plants convert sunlight into chemical energy.
Plants soak up sunlight and use it to synthesize a variety of organic compounds used to drive the plant's metabolism. In the process, plants give off oxygen and water, a process akin to breathing. Called transpiration, this excretion process plays an essential role in balancing atmospheric gases and moisture, and thus in the dynamics of global climate. Hauling equipment up to Manitoba and Saskatchewan in 1994 and '95, the FSU team placed measuring devices called radiometers on towers in the forest canopy to determine exactly how much light was reaching the tops of the trees where most photosynthesis occurs. These devices were placed alongside those of other researchers as one way of checking how accurately the instruments were measuring ambient radiation levels.