Greenhouse gas emissions and carbon sink potential in Eastern Africa rangeland ecosystems: A review

Many activities from livestock husbandry contribute to emission and concentration of carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) gases to the atmosphere; activities such as grazing, manure and urine deposited or stored on land as well as crop farming practices such as tilling, burning of biomass or crop residues. A better understanding of the extent of emission sources and carbon sequestration potential for Eastern Africa rangelands is vital for developing mitigation strategies. In this article, we review the sources of emission with a focus on land conversion for crop farming, livestock husbandry, wildfire/burning and biotic processes such as soil biota activity in the ecosystem. The trade-offs of using rangeland with an emphasis on enhancing carbon sequestration potential are also addressed. This review revealed that many practices that enhance carbon capture process show promising benefits with sink capacity of −0.004 to 13 Mg C ha−1 year−1. However, given multiple land-use and environmental dynamics in Eastern African rangelands, it is imperative to generate more data across various land management and climatic zones in order to ascertain varied sink capacity. Improving carbon sequestration in rangelands through appropriate land management is a promising cost-effective strategy to mitigate climate change. Through improved farming or grazing management practice and restoring of degraded areas, there are significant benefits to enhance carbon sequestration. As rangeland resources are multi-faceted, engaging trans-disciplinary approaches is necessary to allow analyses of co-benefits of improved management or trade-offs degrading.