Long-term fencing decreases plant diversity and soil organic carbon concentration of the Zoige alpine meadows on the eastern Tibetan plateau

Fencing to prevent livestock grazing has widely been implemented to restore vegetation and soils of degraded alpine meadows on the Zoige Plateau in recent decades, but its efficacy is still unclear. This study was designed to investigate the responses of plant community and soil properties to long-term fencing. We surveyed vegetation structure and production, soil physical and chemical properties in three sites, each having paired adjacent plots (i.e. one was fenced for 11–17 years and the other was allowed for regular grazing). Long-term fencing resulted in species loss at the community level and decreased plant species richness at the plot level. Fencing increased aboveground plant biomass and plant litter accumulation but reduced root biomass, and in particular it dramatically increased the aboveground biomass of grasses at the expense of legumes and sedges. Moreover, fencing decreased soil organic carbon and total N concentrations, and soil bulk density, but increased soil water infiltration rate, soil total P and soluble N concentrations, while soil soluble P concentration remained unchanged. These results indicate that long-term (> 11 years) fencing is not beneficial to plant diversity and soil organic carbon sequestration of the Zoige alpine meadows.