An analysis of restoration projects across sub-Saharan Africa found that tree-loss changes extended into surrounding landscapes. Natural regeneration and active restoration were associated with lower tree loss, while agroforestry showed the opposite pattern in the pooled comparisons. The findings vary by country and approach, making neighbouring land part of the environmental outcome rather than a neutral backdrop.
A study of restoration projects in sub-Saharan Africa found changes in tree loss beyond their formal boundaries. Natural regeneration and active restoration were associated with reduced loss in surrounding land, whereas agroforestry showed a contrasting pattern in pooled comparisons. The work examines how restoring one area can accompany changes elsewhere in the landscape.[1], [2]
The researchers assembled nearly 130,000 restoration areas covering about 6.8 million hectares in 27 countries. They compared annual tree loss within projects and in buffers reaching 5 and 10 kilometres from them. Comparison areas included sites restored later and similar places that were never restored. The analysis used changes over time relative to those controls, rather than a randomized assignment of projects to land.[1]
In one comparison, natural regeneration was associated with 6.8 points less tree loss inside projects over ten years and 8.7 points less within the 10 kilometre buffer. Agroforestry instead showed increases in the same comparison. These differences describe percentage points in tree-loss rates. Results varied across countries and control methods. The study measured tree-cover loss, with incomplete project coverage and fewer observations for long-running projects, so its pooled patterns do not determine the outcome of every restoration site.[1]
