We propose observations and analyses to
infer transports of CO2, water vapor, and energy from the natural and the
disturbed regions of Amazonia. We ask support to continue ongoing direct
surface climate and flux measurements at several sites in LBA-ECO. Fluxes
will also be estimated using the boundary layer budget approach. A major
focus will be to determine how carbon fluxes are influenced by natural and
human-induced landscape inhomogeneities. Scales of inhomogeneities
addressed range from the river-land contrast, the pasture-forest contrast, and
the gap-closed canopy contrast inside the forest. Special attention will
go to understanding how changes in agricultural practices in the Amazon alter
carbon exchanges in cleared areas. One new initiative aims to improve
understanding of the respiration rate in forests by studying subcanopy flows.
A second new initiative to quantify canopy structure to relate this structure to
the forest flux tower observations is proposed. This proposal addresses
LBA-ECO Science Questions CD–Q1 CD–Q3b, and LC–Q1.
Our objectives are:
1) To observe
local wind circulations (river and land breezes, drainage flows) and assess
their influence on boundary layer development. To infer surface heat,
water vapor, and CO2 fluxes from temporal changes in their canopy and
boundary layer concentrations .
2) To relate
light availability to the ecosystem to cloudiness, and to determine the
resulting effect on net ecosystem carbon exchange (NEE).
3) To quantify how land use change from pasture to
cultivation alters the carbon budget in one cleared area, and develop
parameterizations of exchange processes for modeling.
4) To quantify the vertical and horizontal structure of
the forest canopy near flux towers in the Tapajos National Forest.
5) To relate canopy structure n to turbulent
canopy-atmosphere exchange in regions of closed-canopy primary forest, near
natural gaps, and in the cut-over mosaic of a selectively logged site.
6) To reduce uncertainties in long-term tower flux
observations of the respiration rate )through better understanding the effect of
subcanopy drainage flows at two LBA-ECO Study Areas.