Influence of climatic variability on tree diversity and smallholders' income in the savanna ecosystem of Sudan

Smallholders and forest-based communities are vital pillars for the green economy, organic agriculture, biodiversity conservation, and sustainable development if well-skilled and effectively involved in managing such resources. However, documents on how this sector is affected by climatic variability in the Sahel region are limited. We responded to this gap and analyzed the effects of rainfall-temperature fluctuations on smallholders and tree diversity in Abu-Gadaf Natural Reserved Forest, Sudan. Findings illustrated that rainfall and temperature variability affected 60%, 55%, and 50% of small-scale farmers, livestock keepers, and non-timber forest products collectors, respectively. Moreover, species richness and stocking density of tree species in the mountainous lands were twice that of flatlands with F and p values of > 123 and < 0.05, correspondingly. Additionally, the total income of smallholders from 2013 to 2022 dropped to < 40%, with strong inverse polynomial relations between income and rainfall-temperature variability (R2 = 0.99, β = − 4.46, and P = 0.02; R2 = 0.97, β = − 2.89, P = 0.02, respectively). However, the growing illegal wood harvesting and domestic animal grazing drive harmful human disturbances and threaten the reserve biodiversity and dynamics. Therefore, to enhance the locals’ income, improve the pollinated flowers, and forested land, we recommend introducing water harvesting techniques, beekeeping activities, and afforestation programs in the study area under an integrative forest policy and regulatory framework.