Grassland changes under grazing stress in Horqin sandy grassland in Inner Mongolia, China

A grazing trial was conducted from 1992 to 1996 in the Horqin sandy grassland area, located in north-eastern China. The trial had four grazing intensity treatments: no grazing (0 sheep ha −1 ), light grazing (2 sheep ha −1 ), moderate grazing (4 sheep ha −1 ) and overgrazing (6 sheep ha −1 ) plots. The overgrazing reduced plant diversity by 87%, vegetation cover by 82%, canopy height by 94%, standing crop biomass by 98%, and root biomass by 92% compared with ungrazed grassland in the fifth year. The proportion of poor quality herbages increased to 86%. Non-grazing assisted recovery of deteriorated vegetation. Though moderate and light grazing also reduced biomass, these treatments did not lead to serious damage to the community species structure. The plant diversity, vegetation cover, and standing biomass in the lightly grazed plots increased over grazing time. The trial showed that a grazing intensity of 2-3 sheep equivalents per hectare was sustainable in the Horqin sandy grassland in Inner Mongolia, China.