Lessons from a participatory forest restoration program on socio-ecological and environmental aspects in Nepal

• We assessed donor-driven participatory forest restoration in Nepal's degraded Churia hills. • Synergistic outcomes emerged by integrating community choices, government support, and flexible donor aid. • Effective policy alignment enhanced ecosystem services, social capital, and ecological functions. • Sustainable financing was lacking, requiring integration into government and community plans. • Tripartite model is practical and participatory for socio-environmental sustainability, encouraging customized adoption. Forest and landscape restoration (FLR) is a key strategy for reviving degraded ecosystems, yet field-level evidence remains limited. Despite being part of over 30 international environmental agreements, Nepal's forest degradation rate exceeded 1.5 % annually. To combat this, donor-supported restoration efforts are ongoing, among others. This study evaluated a donor-backed, community-led restoration initiative within Nepal's Terai Arc Landscape in the Churia Hills of Phulbari, Dang District. Using remote sensing and GIS, we analyzed land cover changes from 1990 to 2020 across 25 community forests (5034 ha) managed by 5061 households. Ground-level biophysical variables were compared between non-intervention areas (NIA), fenced, and planted (FAP) areas, and fenced, planted, and pothole (FPP) areas employing a random sampling technique ( n = 30). Local communities ( n = 40) were consulted, and field observations ( n > 6) were conducted over multiple seasons and years. Results showed an 8.6 % increase in forest cover over three decades, with a 26.1 % rise in restoration experiment sites (FAP and FPP) from 2015 to 2020. FPP sites, with soil-water retention strategies, significantly ( p < 0.05) outperformed NIA and FAP sites, proving effective in reclaiming denuded slopes and conserving water in the face of climate change. While donor-funded projects initiated these activities, their long-term sustainability is uncertain. Locals fear that restoration gains may be lost once funding ends. Restoration efforts must be integrated into government annual budgets and plans to ensure lasting success, with community involvement to promote shared responsibility and ownership. We propose a tripartite FLR model, assigning roles to governments, communities, and other stakeholders for Nepal and similar regions. Our findings provide valuable insights for sustainable planning, especially for restoring degraded landscapes such as dry, denuded slopes, areas affected by anthropogenic disturbances, or combinations, pathways toward achieving sustainable development goals and beyond.