Carbon dynamics of rangeland soils are very complex and only limited detailed research has been conducted to assess the role of management and grazing strategies on soil C changes and the potential for enhanced C sequestration. Soil erosion also can impact the soil C pools in rangeland ecosystems, but much of the erosion does not result in loss of C from the landscape but rather a repositioning on the landscape. In an attempt to estimate the effects of management on the C storage potential of the rangeland ecosystems, we have reviewed the literature on the subject and made some assumptions in order to make some qualitative estimates of C sequestration potential and potential avoided losses of C through management. We believe about 19 Tg C yr-1 can be sequestered through management on lands that are in need of improved management and through soil C regeneration in CRP lands. However, we estimate that 44 Tg C yr-1 can be maintained through ensured good management and by preventing CRP lands from being brought back into crop production. The estimated 63 Tg C yr-1 that can be sequestered and/or prevented from being lost from well- managed rangelands and through maintenance of CRP lands may be small in comparison to the estimates of C sequestration by improved production practices on croplands in the U.S.; however, this level of C storage in a natural ecosystem tends to be more stable and less prone to major C losses through erosional losses and shifts in management.
