How Much of US Dryland's Carbon Stocks Is Being Appropriated By Commercial Grazing Livestock?

Friday, 19 December 2014: 5:30 PM
Robert A Washington-Allen1, Jack McNelis1, Joseph R Roberts1, Zachariah T Seiden1, Ranjani W Kulawardhana2, Matthew C Reeves3 and John E. Mitchell4, (1)University of Tennessee, Knoxville, TN, United States, (2)Texas A & M University, College Station, TX, United States, (3)US Forest Service Missoula, Forestry Sciences Laboratory, Missoula, MT, United States, (4)US Forest Service Fort Collins, Fort Collins, CO, United States
Drylands provide an estimated $1 trillion in ecosystem goods and services to some 36% of the global population. However, the degree of Dryland degradation is unknown with estimates ranging from 10 to 80%. To address this issue we studied the question of how much of above-ground NPP (ANPP) is being appropriated by the US's commercial livestock herd. We compared satellite-derived estimates of US rangeland above-ground NPP (ANPP) in the National Park System (NPS) to grazed US rangelands outside the parks from 2000 to 2012. This provided a test of the hypotheses that NPS ANPP > Rangeland ANPP and NP NPP < Rangeland NPP at low to moderate levels of grazing due to grazing optimization. We found that federally managed wilderness areas had greater productivity than the surrounding rangelands with an estimated mean removal of 58% of NPP by livestock and probably fire, and other land management practices over the 13-year period.