NITROGEN COMPOUND EMISSION FROM BIOMASS BURNING IN TROPICAL AFRICAN SAVANNA FOS DECAFE-1991 EXPERIMENT (LAMTO, IVORY-COAST)/

Gaseous nitrogen compounds (NOx, NOy, NH3, N2O) were measured at groun d level in smoke plumes of prescribed savanna fires in Lamto, in the s outhern Ivory Coast, during the FOS/DECAFE experiment in January 1991. During the flaming phase, the linear regression between delta[NOx] an d delta[CO2] (differences in concentration between smoke plumes and at mosheric background) results volumic emission ratio delta[NOx]/delta[C O2] = 1.37 x 10(-3) with only slight differences between heading and b acking fires. Nearly 90% of the nitrogen oxides are emitted as NO. Ave rage emission ratios of other compounds are: 1.91, 0.047, and 0.145 x 10(-3) for NOy, NH3 and N2O, respectively. The emission ratios obtaine d during this field experiment are compred with corresponding values m easured during former experiments with the same plant species in combu stion chambers. An accurate determination of both the biomass actually burned and of the plant nitrogen content, allows an assessment of emi ssion fluxes of N-compounds from Guinean savanna bums. Preliminary res ults dealing with the influence of fire on biogenic emissions from soi ls are also reported.