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Abstract Thermophilization is the directional change in species community composition towards greater relative abundances of species associated with warmer environments. This process is well-documented in temperate and Neotropical plant communities, but it is uncertain whether this phenomenon occurs elsewhere in the tropics. Here we extend the search for thermophilization to equatorial Africa, where lower tree diversity compared to other tropical forest regions and different biogeographic history could affect community responses to climate change. Using re-census data from 17 forest plots in three mountain regions of Africa, we find a consistent pattern of thermophilization in tree communities. Mean rates of thermophilization were +0.0086 °C·y⁻¹in the Kigezi Highlands (Uganda), +0.0032 °C·y⁻¹in the Virunga Mountains (Rwanda-Uganda-Democratic Republic of the Congo) and +0.0023 °C·y⁻¹in the Udzungwa Mountains (Tanzania). Distinct from other forests, both recruitment and mortality were important drivers of thermophilzation in the African plots. The forests studied currently act as a carbon sink, but the consequences of further thermophilization are unclear. 

Mountain regions are particularly vulnerable to climate change impacts. Yet, little is known about local adaptation responses in African mountain regions, especially if these are incremental or transformational. First, using household questionnaires, we interviewed 1,500 farmers across ten African mountain regions to investigate perceived climate change impacts and adaptation responses. Second, through a reflective process involving all co-authors, we identified: (1) main constraints and opportunities for adaptation, and (2) if adaptation was incremental or transformational. Questionnaire data show that farmers in all sites perceive multiple impacts, and that they mostly respond by intensifying farming practices and using off-farm labour. We established that, while several constraints were shared across sites, others were context specific; and that adaptation was mostly incremental, but that certain attributes (for example, social capital) made three sites in East Africa slightly more transformational.