Effect of grazing exclusion on carbon storage on grazing lands: A Review

Grazing exclusion is increasingly practiced in most grassland ecosystems of the world and is the key management aspect to restore degraded grasslands. This review is initiated to explore the contribution of grazing exclusion in increasing ecosystem carbon sequestration. This review includes research findings from almost all types of terrestrial grassland ecosystems in the world. It produces conclusion from recently conducted research findings regarding the importance of grazing exclusion on biomass and soil carbon stock. It focuses on impact of grazing on carbon sequestration, effect of grazing exclusion on aboveground, belowground and soil carbon storage. Accordingly, grazing exclusion is an effective ecosystem restoration approach to sequester and store carbon in the living biomass and soil profiles. It is important for climate change mitigation. It has a key role mainly in highly degraded and moisture stress grazing lands. It also reduces the loss of carbon from ecosystem to atmosphere via grazing. Grazing exclusion increases biomass productivity of living vegetation. It is critical to increase aboveground carbon storage. Exclusion of highly degraded areas and application of appropriate grazing is relevant to sequester more carbon in to root and microbial biomass. Grazing exclusion also increase soil carbon sequestration through moisture reserve, increasing soil cover and reducing wind erosion. Moderate grazing is also appropriate after complete restoration to increase rate of carbon sequestration from outside. Therefore, efforts have to be applied to expand exclosures in degraded ecosystem considering benefits of local community. Study findings regarding the influence of grazing exclusion on the remaining open grazing lands are meagerly found which is not sufficient for conclusion.