Amazon Forest Carbon Flux Study from Biometric and Eddy Covariance Measurements

Brazil's Tapajós National Forest in Pará was studied to determine its net ecosystem production using two independent methods from 1984 to 2001. Biometric inventories and eddy covariance measurements of CO2 exchange were conducted, providing a dual-method assessment of whether the old-growth forest acted as a carbon source or sink. The dataset, associated with the LBA-ECO project and ORNL_CLOUD, presents a detailed analysis of carbon flux sensitivity to measurement conditions.

Use Cases

• Comparing long-term biometric carbon stock changes (1984-2000) with high-frequency eddy covariance flux data (2000-2001).
• Analyzing the sensitivity of annual carbon flux estimates to the treatment of calm nights using the u* filter parameter.
• Studying the relationship between nocturnal net ecosystem exchange (NEE) and friction velocity (u*).
• Evaluating differences in carbon flux calculations from open-path versus closed-path gas analyzer measurements.
• Assessing the carbon balance of an Amazonian old-growth forest to determine its role as a source or sink.

Strengths

• Employs two independent measurement approaches—biometric inventory and micrometeorological eddy covariance—for cross-validation.
• Provides a 17-year temporal perspective on forest carbon dynamics (1984-2000 for biometrics, plus 2000 2001 for eddy covariance).
• Detailed analysis quantifies a >4 Mg C·ha⁻¹·yr⁻¹ change in annual flux estimate based on calm night treatment, highlighting a key methodological consideration.

Limitations

• Specific column names and dataset size (row count, file size) are not provided by any source platform.
• Conflicting last updated dates exist between sources (2004 vs. 2026), creating uncertainty about metadata freshness.
• The annual carbon balance from eddy covariance is noted as less certain for tropical forests than for temperate ones due to high sensitivity to calm nights.

Provenance

Source

ORNL_CLOUD / LBA-ECO project.

Collection Method

Biometric forest inventories and eddy covariance measurements using open- and closed-path gas analyzers.

Time Range

1984 to 2001.

Freshness

2026-03-13 01:18:08.466520

Geography

Tapajós National Forest, Pará, Brazil (km 83 Tower Site).