Carbon sequestration and soil restoration potential of grazing lands under exclosure management in a semi-arid environment of northern Ethiopia

Exclosures are used to regenerate native vegetation as a way to reduce soil erosion, increase rain water infiltration and provide fodder and woody biomass in degraded grazing lands. Therefore, this study assessed the impact of grazing exclosure on vegetation biomass, carbon sequestration and soil nutrients under five and ten years of grazing exclosures and freely grazed areas in Tigray, northern Ethiopia. Vegetation biomass, carbon stocks and soil nutrients increased with increasing grazing exclusion. However, open grazing lands and five years of grazing exclosure did not differ in aboveground biomass, above-and-belowground carbon stocks. Moreover, ten years of grazing exclosure had a higher (P<0.01) grass, herb and litter carbon stocks compared to five years exclosure and open grazing lands. The total carbon stock was higher for ten years exclosure (75.65 t C ha-1) than the five years exclosure (55.06 t C ha-1) and in open grazing areas (51.98 t C ha-1). Grazing lands closed for ten ...

放牧禁牧区（grazing exclosure）被用于恢复原生植被，以降低土壤侵蚀、提升雨水入渗效率，并为退化放牧地提供饲草与木质生物质。据此，本研究针对埃塞俄比亚北部提格雷地区的5年禁牧区、10年禁牧区及自由放牧区，评估了放牧禁牧区对植被生物量、碳固存及土壤养分的影响。结果显示，植被生物量、碳库与土壤养分随禁牧时长增加而升高。不过，自由放牧区与5年禁牧区在地上生物量、地上及地下碳库方面无显著差异。此外，10年禁牧区的禾草、杂类草与枯落物碳库显著高于5年禁牧区与自由放牧区（P<0.01）。10年禁牧区总碳库为75.65 t C ha⁻¹，高于5年禁牧区的55.06 t C ha⁻¹与自由放牧区的51.98 t C ha⁻¹。封禁达10年的放牧地……