Effect of manipulating animal stocking rate on the carbon storage capacity in a degraded desert steppe

Abstract

Managing the stocking rate is considered one of the most important practices influencing carbon storage on rangeland. The effects of four stocking rates consisting of a non-grazed control (CK), light (0.15 sheep ha−1 month−1), moderate (0.30 sheep ha−1 month−1) and heavy (0.45 sheep ha−1 month−1) were evaluated for impacts on carbon storage taking place on the Desert Steppe of Inner Mongolia, China. Carbon storage was measure in aboveground vegetation, roots and soil in August of 2009, 2011 and 2013. Both aboveground biomass (AGB) and below-ground biomass (BGB) increased significantly as stocking rate decreased. Stocking rate also had a significant effect on both the aboveground and below-ground carbon storage in plant biomass, but had no effect on the soil carbon. Compared to the heavy stocking rate typically practiced by local herders, lower stocking rates increased the total above- and below-ground biomass carbon storage by ≥ 7%. Over the 3 year study, compared to the moderate stocking rate, the rate of carbon sequestration with a light stocking rate was 0.7 Mg C ha−1 year−1. Thus, reducing stocking rate has the potential to increase C sequestration and storage, as well as maintaining animal numbers at a more sustainable level suitable for the Desert Steppe ecosystem.