Profiles of trace gas concentrations from towers at undisturbed forest in the Brazilian Amazon Region
Janaina
Braga
Carmo, CENA/USP, janaina@lbaeco.com.br
(Presenting)
Patrick
Michael
Crill, UNH/USA, patrick.crill@unh.edu
Jadson
Dizencourt
Dias, ESALQ/USP, jadson@lbaeco.com.br
Plínio
Barbosa de
Camargo, CENA/USP, pcamargo@cena.usp.br
Michael
M.
Keller, UNH/USA, michael.keller@unh.edu
We measured N2O, CO2 and CH4 profiles at six heights from ground level to tower-top (up to 62 m) in undisturbed and logged forests using automated and manual sampling systems. Automated systems operated continuously at two sites in the Tapajos National Forest south of Santarem using computer-controlled gas chromatographs to sample analyze three gases at half-hourly frequency. At other LBA sites, we have deployed a new portable profile system to measure profiles of CO2 from sampling tubes in and above the canopy. CO2 was analyzed on-site using a LiCor IRGA. Samples for N2O and CH4 were stored in electro-polished stainless steel flasks and shipped to Santarem for gas chromatographic analysis. We sampled in well mixed conditions during the day and during calm conditions at night when CO2 concentrations were elevated. Results from the automated sampling suggest that at Santarem there is a small, but potentially significant, source of CH4 in the forest even though the soil generally consumes CH4. Results from the manual samplings will be compared to those of the automated system.
Submetido por Janaina Braga do Carmo em 25-MAR-2004