The Potential of Tree-based Land Restoration for Rebuilding Rural Bioeconomy in Africa

There is a growing research and policy interest in tree-based restoration initiatives across Africa, driven by increasing land degradation and its cross-cutting impacts on ecosystems, biodiversity and livelihoods. Yet, minimal studies have attempted to quantify the multiple benefits and impacts of trees on restoration at various levels. The aim of this study was to document the quantified evidence of tree-based systems, including agroforestry, farmer managed natural regeneration, and assisted natural regeneration, on restoration in Africa. A literature review analysis method was adopted, focusing on papers and reports published in peer reviewed and grey literature. The findings revealed that tree-based systems have considerable potential to sequester and store carbon and contribute towards carbon mitigation. The sequestration potential ranged from below one to over 300 tonnes per hectare per year for above and below ground carbon depending on the tree species intensification and biodiversity, cropping and livestock systems, tree management practices, and spatial-temporal arrangements of the tree within the system. Notably, sequestration of greenhouse gases was higher in tree-based systems compared to the traditional and pasture systems. Tree-based systems also contribute significantly to environmental adaptive and resilience capacity. Such included increased biodiversity enhanced organic soil matter, increased farm productivity, improved soil moisture content, improved habitats, and reduced soil erosion. To illustrate, maize productivity in agroforestry farms increased by between 20% and 400% compared to treeless fields. On the other hand, tree-based systems led to decline of sediment load by between 30-60%, increased groundwater recharge by over 20%, and reduced soil erosion by between 20-60%. From a socioeconomic perspective, tree-based systems increased household income by upto 40% annually, diversified food and dietary sources, reduced hunger months by upto 3 months annually, and improved household capacity in food production especially among women and youth. To illustrate, agroforestry systems increased household income levels by between 100 and 3,000 USD per hectare in Ghana through diversified income sources such as sale of non-timber products like fruits, nuts, fodder and medicinal plants. Other documented impacts of tree-based systems included improved biodiversity conservation, improved soil and water conservation, and improved microclimate amelioration. The study concludes by noting the significant potential of tree-based systems in restoration in Africa, with associated biodiversity, environmental and socioeconomic impacts. However, the benefits can only be optimized when the right tree systems are established in the right places and the right management practices are put in place.