NPP Grassland Bridger: Above- and Below-Ground Biomass, 1970-1973

From 1970 to 1973, this dataset monitors plant biomass dynamics at a grassland site in the Rocky Mountains, with data collected at roughly two-week intervals during growing seasons. It contains above-ground live biomass, standing dead matter, litter, and below-ground biomass for roots and crowns at two soil depths, under ungrazed and moderately grazed treatments. The data were collected as part of the U.S. Grassland Biome Project of the International Biological Program (IBP) across ten central and western U.S. sites.

Use Cases

• Estimating above-ground net primary production (ANPP) based on peak biomass of individual species.
• Estimating below-ground net primary production (BNPP) based on positive increments in total root biomass.
• Comparing plant biomass dynamics between ungrazed and moderately grazed grassland treatments.
• Analyzing seasonal growth patterns from high-frequency (bi-weekly) harvest data during growing seasons.
• Integrating site-specific biomass data with climate records from a nearby weather station.

Strengths

• Provides high-temporal-resolution data with biomass sampled at roughly two-week intervals during growing seasons.
• Includes paired above- and below-ground biomass measurements for two distinct grazing treatments.
• Part of a coordinated, multi-site study (ten grassland sites) under the U.S. IBP Grassland Biome Project.
• Data files have been checked for accuracy and are identical to those originally published in 1998.

Limitations

• Metadata completeness is low: column names, row counts, and file sizes are not specified in the provided sources.
• Data freshness is a concern: the core data was originally published in 1998, with a documentation update noted for 2026 on one platform but a 1994 last update on another, indicating a conflict or stale primary data.
• Spatial scale is limited to a single study site, though it was part of a larger network.

Provenance

Source

National Aeronautics and Space Administration (NASA), collected under the U.S. Grassland Biome Project of the International Biological Program (IBP).

Collection Method

Biomass data monitored by harvest technique at the Bridger grassland study site.

Time Range

1970-1973

Freshness

2026-04-09 (documentation update on datagov), but data is from 1998 and another platform lists last update as 1994-12-31.

Geography

Bridger grassland study site in the Rocky Mountains (45.78 N, -110.78 W, Elevation 2,340 m); climate data from Big Timber weather station (45.80 N, -110.00 W, Elevation 1,249 m).