STUDYING THE EFFECT OF ELEVATED CO2 IN THE OPEN IN A NATURALLY ENRICHED ENVIRONMENT IN CENTRAL ITALY

A gas vents area was recently localized in Central Italy. The gas emitted from the vents is composed by 92% of carbon dioxide and this produces an anomaly in the composition of the atmosphere over an area of about 2 ha. Atmospheric carbon dioxide concentration was measured by means of an infrared gas analyzer and diffusion tubes in several points and for some days within the area. Measurements revealed that the site can be at least divided into three sub-areas having increasing CO2 concentration in the air. A preliminary analysis of natural vegetation in the area was conducted by counting stomatal and epidermal cells number and measuring guard cell size on leaves of several oak trees growing both near and far away from the vents. This analysis suggested that elevated CO2 may have reduced the size of guard cells leaving stomatal density and stomatal index unaltered.