OTTER Project: Forest NPP and Biomass Across Oregon, 1989-1991

Six sites along a 250-km west-east transect in Oregon, USA, provide measurements of forest ecosystem productivity. The dataset includes net primary productivity (NPP), leaf area index (LAI), and biomass estimates, with values varying approximately tenfold across the climatic gradient. Data files are identical to those originally published in 1999, with only documentation updated.

Use Cases

• Modeling carbon sequestration potential based on measured NPP values ranging from 300 to 2,570 g/m2/yr.
• Analyzing the relationship between leaf area index (0.4 to 8.6 m2/m2) and intercepted photosynthetically active radiation (22% to 99.5%).
• Calibrating remote sensing products for biomass estimation using ground measurements from 1,080 to 71,080 g/m2.
• Studying ecosystem gradients across a precipitation and elevation transect in the Pacific Northwest.

Strengths

• Provides specific, quantified measurements for key ecological variables (e.g., NPP, LAI, biomass) at six distinct sites.
• Data has been checked for accuracy and remains consistent with the original 1999 publication.
• Cross-platform presence (Data.gov, NASA Earthdata) indicates established use and validation.

Limitations

• Column names and exact row count are not specified in the provided metadata.
• Data is historical (1989-1991) and may not reflect current forest conditions.
• There is a conflict in the 'last updated' metadata between 1991-12-31 and 2026-04-09, suggesting documentation updates but no new data.

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

Field measurements collected for the Oregon Transect Ecosystem Research (OTTER) Project.

Time Range

1989 to 1991

Freshness

2026-04-09 (documentation update); underlying data from 1999 covering 1989-1991.

Geography

Six sites along a 250-km west-east transect in Oregon, USA, Pacific Northwest.