Addressing risks to biodiversity arising from a changing climate: The need for ecosystem restoration in the Tana River Basin, Kenya

RESEARCH ARTICLE Addressing risks to biodiversity arising from a changing climate: The need for ecosystem restoration in the Tana River Basin, Kenya Rhosanna L. M. JenkinsID1*, Rachel F. Warren1,2, Jeff T. PriceID1,2 1 School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom, 2 Tyndall Centre for Climate Change Research, University of East Anglia, Norwich, United Kingdom * Rhosanna.Jenkins@uea.ac.uk Abstract 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 distribu- tion 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 great- est 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 pro- tect 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 bio- diversity protection and adaptation options in Kenya. Introduction Climate and land use change have been and will continue to be the two most significant threats to global biodiversity [1, 2]. The substantial risk that climate change poses to biodiversity at the global scale [3, 4] and species’ responses, in particular through shifts in ranges, are widely researched [5, 6]. Biodiversity has been responding and adapting to changes in climate throughout history, but many species may be ill-equipped to deal with the current, more rapid rate of warming [7]. There will be species that prefer the warmer climates and become more PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0254879 July 21, 2021 1 / 25 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Jenkins RLM, Warren RF, Price JT (2021) Addressing risks to biodiversity arising from a changing climate: The need for ecosystem restoration in the Tana River Basin, Kenya. PLoS ONE 16(7): e0254879. https://doi.org/10.1371/ journal.pone.0254879

Editor: Daniel de Paiva Silva, Instituto Federal de Educacao Ciencia e Tecnologia Goiano - Campus Urutai, BRAZIL Received: May 22, 2020 Accepted: July 6, 2021 Published: July 21, 2021 Copyright: © 2021 Jenkins et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All files are available from the OSF database: https://osf.io/frsu9/. Funding: RJ was supported by the Natural Environment Research Council (https://nerc.ukri. org/) through the EnvEast Doctoral Training Partnership [grant number NE/L002582/1], Studentship Award Reference 1511895. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.