Bridger Site (Montana, USA)

Productivity of a mountain grassland was monitored at the Bridger study site during 1970 and 1972. 
Dynamics of above-ground plant biomass were monitored at roughly 2-week intervals during the 
growing season. Data on above-ground live biomass, standing dead matter and litter are available, 
for two replications of a grazed and an "ungrazed" (relatively undisturbed) treatment. 
Above-ground net primary production (ANPP) was estimated conservatively, by summing peak
biomass of individual species, and below-ground production (BNPP) estimated as the sum of 
positive increments in total root plus crown biomass. 

Data were collected as part of a coordinated study over 1-3 years at ten grassland sites of 
the central and western United States, under the US Grassland Biome Project of the 
International Biological Program (IBP). 

The Bridger study site (45.78 N 110.78 W) is situated at the US Forest Service Bangtail Ridge 
Ranger Station in the Rocky Mountains, 22 km north east of the city of Bozeman, Montana. 
The ungrazed treatment area had been protected from grazing since 1930. The high mountain 
meadow is surrounded by forests dominated by Abies lasiocarpa and Pinus contorta. 

Contact: Dr. W.K. Lauenroth
Natural Resource Ecology Laboratory
Colorado State University
Fort Collins, Colorado 80523
USA
Telephone: +1 (970) 491-7581
Fax: +1 (970) 491-1965
Email: billl@cnr.colostate.edu

Alternative Contact: Prof. Tad W. Weaver
Department of Biology
Montana State University
P.O. Box 173460
Bozeman, MT 59717-3460
USA
Telephone: +1 (406) 994-3270/ 4548
Fax +1 (406) 994-6029
Email: tweaver@montana.edu