Habitat Suitability and Eco-physiological Drivers of Selected Economically and Ecologically Important Dioscorea species: Implications for Food Security and Conservation in Ethiopia

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Yam is a key multipurpose tuber crop for smallholder farmers in southern, southwestern, and western Ethiopia, contributing to food security, income generation, traditional medicine, and resilience of farming systems. Despite its importance, its climatic resilience remains poorly understood. Yam production is influenced by biotic and abiotic factors, including climate change, drought, land use change, soil infertility, pests, and diseases. Limited information exists on how these factors affect habitat suitability and production potential of yams. This study predicts the ecological thresholds, current and future habitat suitability, and distribution of Dioscorea bulbifera, Dioscorea cayenenesis , and Dioscorea alata under changing environmental conditions in Ethiopia. Occurrence records were compiled from literature, National Herbarium of Ethiopia, GBIF, EBI, and WorldClim. After spatial filtering, 343, 215 and 191 occurrence points, and 15, 13 and 16 environmental predictor variables were used for D. alata , D. bulbifera , and D. cayenenesis respectively. An ensemble modeling approach using six algorithms (GLM, BRT, MaxEnt, SVM, MARS, and RF) with 10 replications was applied. Habitat suitability was projected for current and future climate scenarios (SSP 4.5 and SSP 8.5) for the 2050s and 2070s. Identified key predictors variables for D. alata (Bio14, Bio15, Bio18, Bio19, SOC, SR), for D. bulbifera (Bio15, Bio19, SOC, Bio18, Bio9, Bio7, CEC), and for D. cayenensis (SOC, Bio7, Bio15, SR, Bio14, Bio19, Bio18, Bio9), while soil pH had minimal influence. Model performance was high: D. alata ; AUC =0.95; TSS=0.8 ; D. bulbifera; AUC = 0.92 ; TSS = 0.72 , and D. cayenenesis; AUC = 0.93; TSS =0.74). Currently, southern and southwestern Ethiopia are the most suitable regions, with estimated suitable areas of ∼86,263 km 2 for D. alata , ∼12,089 km 2 for D. bulbifera , and ∼50,353 km 2 for D. cayenenesis . Under the worst climate change scenario (SSP 4.8) by the 2070’s, suitable habitats are projected to expand significantly. Habitat range sizes may increases by 117,456.90 km 2 (36.2%), 232,994.75 km 2 (90.8%), and 278,009.34 km 2 (452.1%) for D. alata, D. bulbifera, and D. cayenensis respectively. Future suitability significantly expands into central and northwestern Ethiopia, particularly for D. bulbifera and D. cayenensis. These findings highlight opportunities to enhance climate adaptation, farmer livelihoods, and food security through targeted policies, dissemination, and capacity building, and provide a scientific basis for improving yam management practices in Ethiopia.