Institute of Meteorology and Climate Research, Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology (KIT), Garmisch-Partenkirchen, Germany.
Mazingira Centre, International Livestock Research Institute (ILRI), Nairobi, Kenya.
Sci Rep. 2021 Nov 11;11(1):22094. doi: 10.1038/s41598-021-01706-4.
We applied the process-based model, LandscapeDNDC, to estimate feed availability in the Sahelian and Sudanian agro-ecological zones of West Africa as a basis for calculating the regional Livestock Carrying Capacity (LCC). Comparison of the energy supply (S) from feed resources, including natural pasture, browse, and crop residues, with energy demand (D) of the livestock population for the period 1981-2020 allowed us to assess regional surpluses (S > D) or deficits (S < D) in feed availability. We show that in the last 40 years a large-scale shift from surplus to deficit has occurred. While during 1981-1990 only 27% of the area exceeded the LCC, it was 72% for the period 2011-2020. This was caused by a reduction in the total feed supply of ~ 8% and an increase in feed demand of ~ 37% per-decade, driven by climate change and increased livestock population, respectively. Overall, the S/D decreased from ~ 2.6 (surplus) in 1981 to ~ 0.5 (deficit) in 2019, with a north-south gradient of increasing S/D. As climate change continues and feed availability may likely further shrink, pastoralists either need to source external feed or significantly reduce livestock numbers to avoid overgrazing, land degradation, and any further conflicts for resources.
我们应用基于过程的模型 LandscapeDNDC 来估计西非萨赫勒和苏丹草原农业生态区的饲料供应情况，以此作为计算区域牲畜承载能力 (LCC) 的基础。将饲料资源（包括天然牧场、灌木和农作物残茬）提供的能量供应 (S) 与牲畜种群在 1981-2020 年期间的能量需求 (D) 进行比较，使我们能够评估饲料供应的区域盈余 (S>D) 或赤字 (S<D)。我们表明，在过去的 40 年中，已经发生了从盈余到赤字的大规模转变。虽然在 1981-1990 年期间，只有 27%的地区超过了 LCC，但在 2011-2020 年期间，这一比例达到了 72%。这是由于气候变化和牲畜数量增加分别导致总饲料供应量减少了约 8%，以及饲料需求每十年增加了约 37%。总体而言，S/D 从 1981 年的2.6（盈余）下降到 2019 年的0.5（赤字），呈南北梯度增加。随着气候变化的持续和饲料供应可能进一步减少，牧民要么需要寻找外部饲料，要么大幅减少牲畜数量，以避免过度放牧、土地退化和进一步的资源冲突。
