Track 2-05: Carbon Sequestration and Cycling
Description
Grazing lands in North China are often excessively grazed and widely degraded, while hay-making lands appear to be in relatively good condition due to grazing exclusion, but they are facing a continuous loss of nutrients in the harvested biomass. In semiarid grasslands, plant productivity and community composition are significantly altered by grazing and haying. Grazing mostly leads to negative effects on aboveground productivity, however root biomass seems to increase with moderate grazing (Gao et al. 2009; Derner et al. 2006), although responses can vary. Aboveground biomass removal can increase C3 grass dominance and productivity (Hofer and Bragg 1981). Grazing exclusion is a valuable mechanism of sequestering soil C (He 2008). However, grazing can change C allocation patterns and affect the amount of C entering the soil. Here we examine the potential effects of common management practices (exclusion with fencing, grazing and hay-making) on semiarid grasslands above- and below-ground C pools. The primary objective of this study was to evaluate the potential of grazing exclusion and annual last-summer haying in previous grazing lands on the storage of C in semiarid grasslands of northern China.
Included in
Influence of Grassland Management on Carbon Allocation in a Semiarid Temperate Steppe
Grazing lands in North China are often excessively grazed and widely degraded, while hay-making lands appear to be in relatively good condition due to grazing exclusion, but they are facing a continuous loss of nutrients in the harvested biomass. In semiarid grasslands, plant productivity and community composition are significantly altered by grazing and haying. Grazing mostly leads to negative effects on aboveground productivity, however root biomass seems to increase with moderate grazing (Gao et al. 2009; Derner et al. 2006), although responses can vary. Aboveground biomass removal can increase C3 grass dominance and productivity (Hofer and Bragg 1981). Grazing exclusion is a valuable mechanism of sequestering soil C (He 2008). However, grazing can change C allocation patterns and affect the amount of C entering the soil. Here we examine the potential effects of common management practices (exclusion with fencing, grazing and hay-making) on semiarid grasslands above- and below-ground C pools. The primary objective of this study was to evaluate the potential of grazing exclusion and annual last-summer haying in previous grazing lands on the storage of C in semiarid grasslands of northern China.
