An experiment was conducted in the Guyana forest in March 1985, during which C2--C6 non methane hydrocarbons (NMHC) were measured in the air, together with CO2 and its associated 13C isotopic composition. Owing to the very high atmospheric stability, strong vertical concentration gradients were observed close to the soil surface. Simple assumptions allow showing that NMHC are mainly destroyed by OH radicals whose concentration seems to be surprisingly high, around 1¿107 radicals cm-3. An indirect photochemical production of these radicals is proposed.

On the other hand, the fluxes of the different NMHC emitted from the litter were found to be small, in the range of 10-7 to 10-6 g of carbon per hour and per m2. ¿ American Geophysical Union 1987