Open AccessAmazon rain forest subcanopy flow and the carbon budget: Santarém LBA‐ECO site
Author(s) -
Tóta Julio,
Fitzjarrald David R.,
Staebler Ralf M.,
Sakai Ricardo K.,
Moraes Osvaldo M. M.,
Acevedo Otávio C.,
Wofsy Steven C.,
Manzi Antonio O.
Publication year - 2008
Publication title -
journal of geophysical research: biogeosciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2007jg000597
Subject(s) - advection , canopy , environmental science , eddy covariance , amazon rainforest , tree canopy , atmospheric sciences , mesoscale meteorology , geology , climatology , geography , ecosystem , ecology , physics , archaeology , biology , thermodynamics
Horizontal and vertical CO 2 fluxes and gradients were made in an Amazon tropical rain forest, the Tapajós National Forest Reserve (FLONA‐Tapajós: 54°58′W, 2°51′S). Two observational campaigns in 2003 and 2004 were conducted to describe subcanopy flows, clarify their relationship to winds above the forest, and estimate how they may transport CO 2 horizontally. It is now recognized that subcanopy transport of respired CO 2 is missed by budgets that rely only on single point eddy covariance measurements, with the error being most important under nocturnal calm conditions. We tested the hypothesis that horizontal mean transport, not previously measured in tropical forests, may account for the missing CO 2 in such conditions. A subcanopy network of wind and CO 2 sensors was installed. Significant horizontal transport of CO 2 was observed in the lowest 10 m of the canopy. Results indicate that CO 2 advection accounted for 73% and 71%, respectively, of the carbon budget for all calm nights evaluated during dry and wet periods. We found that horizontal advection is likely important to the canopy CO 2 budget even for conditions with the above‐canopy friction velocity higher than commonly used thresholds.