Small-scale monospecific Eucalyptus plantations in the mountainous areas of Lubero (eastern DR Congo): a pathway for sustainability or a socio-economic survival trade-off?

Monospecific Eucalyptus plantations have expanded markedly in the mountainous tropical regions of the eastern Democratic Republic of the Congo. However, their socio-economic and ecological implications remain insufficiently documented, particularly regarding farmers’ social perceptions and the contribution of these plantations to livelihoods. This study addresses these gaps by examining smallholders’ perceptions of the social, economic and ecological impacts of Eucalyptus, while also assessing its economic and energy values, and its contribution to livelihoods. Data were collected through a survey of 250 rural households using a structured questionnaire. Binary and ordinal logistic regressions were employed to analyse the determinants of perceptions and planting intentions, while economic value was assessed through tree and charcoal sales. Annual gross margins were compared using the Kruskal–Wallis test. The results reveal the high socio-economic acceptance of Eucalyptus (51–98%), despite widespread recognition of its negative ecological impacts (70–94%), particularly concerning food security, soil fertility, water availability, and land-use competition. Perceptions of Eucalyptus-related environmental risks are driven by concerns over food security and biodiversity, whereas perceived benefits strongly reinforce the intention to plant Eucalyptus trees (p < 0.05). Small-scale monospecific Eucalyptus plantations support livelihoods by contributing to food provision (82.4%) and schooling (47.6%). Annual gross margins per household vary by utilisation method (p < 0.01): small-diameter trees provide the most stable income (USD 374.4 ± 221.4 per year), charcoal yields intermediate income (USD 358.3 ± 211.6 per year) and standing trees generate the highest, yet most variable, income (USD 556.9 ± 425.8 per year). These findings underscore the duality between immediate economic benefits and long-term ecological risks. The study advocates for integrating Eucalyptus into sustainable agroforestry systems, further assessing its impact on soils and food security, and examining local value chains to optimise profit distribution among stakeholders.