Rainfall and Temperature Variability, Climate Vulnerability and their Implications for Agrobiodiversity and Smallholder Farmer Livelihoods in The Mountainous Agroecological Zone of Rubanda District, Southwestern Uganda

Abstract

Climate variability threatens agrobiodiversity and livelihood sustainability in mountain agroecological systems. This study analysed rainfall and temperature variability, assessed household climate vulnerability, and examined implications for agrobiodiversity and smallholder farmer livelihoods in Rubanda District, southwestern Uganda. Climate data for 1993-2024 were obtained from TerraClimate and cross-validated with available national meteorological records, while household information was collected using questionnaires, focus group discussions and key-informant interviews. Data were analysed using standard descriptive and inferential methods, including Mann-Kendall trend analysis, Sen's slope estimator, analysis of variance, Spearman correlation and regression. Rainfall displayed marked inter-annual variability, but long-term trends were not significant (p > 0.05). Minimum and maximum temperatures increased significantly, with Sen's slopes of 0.0038-0.0040 °C year⁻¹ and 0.0024-0.0026 °C year⁻¹, respectively. Mean livelihood vulnerability was greatest in Hamurwa (0.184 ± 0.075) and Ikumba (0.168 ± 0.072), followed by Ruhija (0.133 ± 0.065) and Bubaare (0.110 ± 0.065). Respondents reported declining crop yields (84.6%), food insecurity (78.3%), soil erosion (73.1%) and reduced household income (71.6%). Crop diversification, agroforestry and crop-livestock integration strengthened adaptive capacity. The study recommends locally targeted climate-smart agriculture, improved climate information and conservation of agrobiodiversity to enhance resilience in mountainous farming systems.