Spatiotemporal trends of climate change and variability: impacts on coffee production in Abaya and Gelana Woredas, Southern Ethiopia

Abstract

The purpose of this study was to investigate the spatiotemporal trends and variability of climate impacts on coffee production in Abaya and Gelana Woredas. To clarify reliable data from the participants, the study utilized a mixed-research approach. Combining quantitative climate analysis (Mann–Kendall test, Sen’s slope, and rainfall indices) with qualitative data from surveys and interviews, this research assessed how climate variability, socioeconomic factors, and physical conditions affect coffee yield. Statistical analysis (regression and t-tests) reveals significant climate trends across the study area, including warming nighttime temperatures (Tmin), cooling daytime temperatures (Tmax), and seasonal rainfall fluctuations. Rainfall trends varied among kebeles: In Bunata, Belg (Z = 1.07) and Meher (Z = 1.03) conveyed moderate but non-significant increases, although annual rainfall showed a near-significant decline (Z = − 1.84, Q = − 0.076). In contrast, Guangawa Badiya, Giwe, and Jirme exhibited positive rainfall trends in both Belg (Z = 2.21) and Meher (Z = 2.67), while Odo Mike experienced negative rainfall trends, particularly in Meher (Q = − 0.391) and annually (Q = − 0.660). Temperature trends revealed a decrease in Tmax across all sites (Bunata − 0.61, Guangawa Badiya − 0.66, Odo Mike − 0.45, Giwe − 0.43), while Tmin increased entirely, with notable seasonal variability in Tmax. Regression modeling showed a strong correlation (R = 0.871) between climate variability, soil erosion, land size, and coffee production, explaining 83.2% of the variation in yields. Key adaptation strategies reported by farmers included intercropping (8.7%), income diversification (8.7%), cultivar selection (8.6%), agroforestry (8.5%), and integrated pest management (IPM) (7.8%). While rising Tmin, decreasing Tmax, and rainfall variability contributed to variations in coffee production in Guangawa Badiya, Giwe, and Jirme, these changes led to a decline in Bunata and Odo Mike. Coffee production has been impacted by climate change due to reducing the diurnal temperature range, hindering blooming and bean development, and making pests more vulnerable. Intense rainfall causes soil erosion and nutrient loss, while irregular rainfall impacts important development phases, resulting in flower drop and low yields. This study underscores the importance of adaptive strategies such as intercropping, agroforestry, income diversification, enhanced water management, and government support in ensuring the sustainability of coffee farming amidst ongoing climate fluctuations.