School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom.
Tyndall Centre for Climate Change Research, University of East Anglia, Norwich, United Kingdom.
PLoS One. 2021 Jul 21;16(7):e0254879. doi: 10.1371/journal.pone.0254879. eCollection 2021.
Climate change is projected to have significant effects on the distribution of species globally, but research into the implications in parts of Africa has been limited. Using species distribution modelling, this study models climate change-related risks to the terrestrial biodiversity (birds, mammals, reptiles, amphibians and plants) of Kenya's economically-important and ecologically diverse Tana River Basin. Large reductions in species richness are projected with just 2°C warming (relative to preindustrial levels) with birds and plants seeing the greatest impact. Potential climate refugia for biodiversity are identified within the basin, but often overlap with areas already converted to agriculture or set aside for agricultural expansion, and the majority are outside protected areas. Similarly, some protected areas contain no projected refugia at higher levels of global warming, showing they may be insufficient to protect the basin's biodiversity as climate changes. However, risks to biodiversity are much smaller if the Paris Agreement's goal of limiting global warming to 'well below 2°C' warming, rather than 2°C only, is met. The potential for refugia for plants and animals decreases strongly with warming. For example, 82% of the basin remaining climatically suitable for at least 75% of the plants currently present at 1.5°C warming, as compared with 23% at 2°C and 3% at 4.5°C. This research provides the first assessment of the combined effects of development plans and climate change on biodiversity of the Tana River Basin, including identifying potential areas for restoration, and contributes to a greater understanding of biodiversity protection and adaptation options in Kenya.
气候变化预计将对全球物种分布产生重大影响，但对非洲部分地区的影响研究一直有限。本研究利用物种分布模型，对肯尼亚具有经济重要性和生态多样性的塔纳河流域的陆地生物多样性（鸟类、哺乳动物、爬行动物、两栖动物和植物）与气候变化相关的风险进行建模。与工业化前水平相比，仅升温 2°C 就预计会导致物种丰富度大幅减少，鸟类和植物受到的影响最大。在流域内确定了生物多样性的潜在气候避难所，但这些避难所往往与已经转为农业或预留用于农业扩张的地区重叠，而且大多数都在保护区之外。同样，一些保护区在更高水平的全球变暖下没有预测到避难所，这表明随着气候变化，它们可能不足以保护该流域的生物多样性。然而，如果《巴黎协定》的目标是将全球变暖限制在“远低于 2°C”，而不仅仅是 2°C，那么对生物多样性的风险就会小得多。随着变暖，动植物的避难所潜力会强烈下降。例如，与 2°C 相比，在 1.5°C 变暖时，盆地仍有 82%的气候适合目前存在的植物的 75%以上，而在 2°C 时为 23%，在 4.5°C 时为 3%。这项研究首次评估了发展计划和气候变化对塔纳河流域生物多样性的综合影响，包括确定潜在的恢复区域，并有助于更好地了解肯尼亚的生物多样性保护和适应选择。
