Technical Abstract: Accurately estimating root biomass is critically important for understanding how below ground carbon storage is affected by different plant life forms and by fire. We compared a new soil coring technique with traditional quantitative pits for determining root biomass. We conducted the study in an existing Joint Fire Sciences Demonstration Area in the central Great Basin that is representative of a shrub (sagebrush) ecosystem exhibiting tree (pinyon and juniper) encroachment. The Demonstration Area had a prescribed burn implemented four years prior to our study, and we sampled both control and burned plots. The samples were stratified across three microsites (interspace, shrub, and tree) and four soil depths (0-8, 8-23, 23-38, and 38-52 cm) to determine the effects of plant life form and burning on root biomass. We found that total root biomass estimates were similar for quantitative pits and our new soil core. However, cores tended to show a more even distribution of root biomass across all microsites and depths than pits. Overall results indicated that root biomass differs significantly among microsites and soil depths, and that the amount of root biomass at a given depth differs among microsites. Burning reduced root biomass in our study by 13-23 percent, and altered the spatial distribution of root mass.