Response of soil water and carbon storage to short-term grazing prohibition in arid and semi-arid grasslands of China

Abstract

Appropriate management practices play an important role in the sustainable use of grassland. Prohibition of grazing is beneficial to restore degraded grasslands and increase carbon stocks. To determine the effects of short-term grazing prohibition upon carbon and water stocks in grassland ecosystems an ecohydrological experimental station was established in Erlitu Ranch, Xilinguole League, Inner Mongolia. The station was used to conduct research on vegetation, moisture and other characteristics diagnostic of grassland health. Changes in green above-ground plant parts, below-ground biomass, soil carbon content, soil water content, pH, and total nitrogen between grassland with and without grazing were assessed by ANOVA, and structural equation modelling was used to investigate the interactions among these various factors. The results revealed that after grazing prohibition, the above-ground and below-ground biomass, soil total nitrogen, pH, and soil water content increased. Soil carbon storage increased by 1.27% in the soil layers above 30 cm and decreased by 13.74% in the deeper layers. Correlation analysis indicated that soil water content was positively correlated with carbon content, and closely related to other factors. Grazing prohibition improves soil physical properties and soil water reserves, which indicates an effective management practice in promoting the recovery of grasslands in arid areas.