Assessment of growth and survival rate of native tree species across COMBIO project areas in Eastern Province of Rwanda

Restoration of degraded land and deforested landscapes using native tree species has been claimed important in addressing global environmental challenges. In Rwanda, the COMBIO project aims at restoring the degraded lands and forests in the Eastern Province using native trees to enhance ecological resilience and support community livelihoods. This study assesses the growth and survival rates of one-year-old native tree species planted in six sanctuaries under COMBIO project areas between 2024 and 2025. Using Cochran’s formula and stratified random sampling, we measured 2301 of 60,335 planted trees for height and diameter, with survival rate tracked via living/dead/missing counts. Data on tree locations were captured using Differential Global Positioning System (DGPS) and analysed in ArcGIS Pro alongside topography, rainfall, and temperature data. Interviews and field observations with technicians, agronomists, and cooperative members captured qualitative insights on influencing factors and best practices.We analysed the growth and survival data in Excel and R Software; The results reveal significant variation in tree growth and survival rates, which was primarily driven by site-matching and management practices rather than species-inherent traits alone. Fast-growing species including Acacia polyacantha , Entada abyssinica , Ficus sur , Maesopsis emenii and Ziziphus mucronata reached average heights of 1–2.7 m and base-diameter of 3–5.8 cm, while slow-growing species like Ficus thonningii and Pappea capensis remained below 1m of height and 1 cm of diameter. Survival rates ranges from 60 to 100% for resilient species, while lower survival reflects poor adaptation and management challenges. Key influencing factors include rainfall variability, pest infestation, livestock grazing, competition from unwanted vegetation, inadequate planting techniques, and limited technical knowledge among the labourers, highlighting that the proper species selection, implementation of Taungya system, high maintenance practices, use of quality seedlings and enhanced community awareness of tree management are the best practices for restoration success.