This data set contains three ASCII files (.txt format). Two files contain above- and below-ground biomass and productivity data for a mixed prairie grassland, one file for an ungrazed treatment and the other for a moderately grazed treatment. The study site (38.87 N, - 99.38 W, Elevation 714 m) is located in the central Great Plains near the city of Hays, Kansas, about 400-km west of Kansas City. The third file contains monthly and annual climate data for the period 1891-1994 obtained from a weather station (38.87 N, -99.38 W, Elevation 613 m) located at the Hays grassland study site.

Dynamics of above-ground living and dead plant biomass were monitored by the harvest technique at roughly 2-week intervals during the growing season of 1970. Total below-ground biomass was sampled at the same intervals by manual coring within the harvested plots to a depth sufficient to include at least 90% of the root mass. 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).

Annual above-ground net primary production (ANPP) was estimated conservatively by summing peak biomass of individual species. These values were 363 g/m2/year for ungrazed and 372 g/m2/year for grazed grassland plots. Annual below-ground net primary production (BNPP) was estimated as the sum of positive increments in total root biomass (including root crowns); 1,062 g/m2/year for ungrazed and 855 g/m2/year for grazed grassland plots.