Biospheric influence on carbon dioxide measurements in Italy

The study concerning carbon dioxide measurements taken during the 1997, 199 8 and 1999 summer campaigns at two different altitude stations and biospher ic conditions are presented. The higher station (Mt. Cimone, 2165m a.s.l.) is characterised by 360 degrees free horizon and is located on a rocky moun tain while the lower (Ninfa lake, 1550m a.s.l.) is located inside the red s pruce and beech forest. The different behaviour of CO2 at the two mountain stations has been registered. It shows the strong effect of nighttime soil emission and vegetation respiration on CO2 mixing ratio increases and of di urnal vegetative activity on CO2 concentration decreases at the lower measu rement site. The baseline character of the higher measurement site has been confirmed by comparison of CO2 diurnal amplitudes recorded at the two stat ions. (C) 2000 Elsevier Science Ltd. All rights reserved.