Potential negative effects of the Green Wall on Sahel's biodiversity

Abstract

Article impact statement: If not carefully assessed, landscape changes could negatively affect dryland-adapted imperiled biodiversity in the Sahel.

Upscaling tropical restoration to deliver environmental benefits and socially equitable outcomes

“…Natural regeneration can also provide many ecosystem service benefits, including hydrological regulation 39,40 (Figure 3C) (A) The Great Green Wall initiative aims to reduce land degradation, improve climate adaptation, and strengthen food security by restoring arid-resistant landscapes in a $15 km wide belt across 7,775 kilometres of Africa. Costing $US$43 billion by completion, 16% of the project was underway in 2020 8 . Beyond climate and livelihood benefits, afforestation could negatively affect fauna.…”

“…Two critical ones are embedding long-term resilience against climate change and avoiding misapplied restoration practices within ecologically distinct rangeland and savanna woodland systems. Inappropriate planting in rangelands and savanna woodlands Different processes maintain ecosystem health in forests and grasslands, where fire and mega-herbivores underpin community dynamics 8,11 . Restoration programmes often fail to distinguish ancient intact savannas 8,11 or else have miscalculated the amount of natural tree cover already occurring in many dryland areas 88 (Figure 2D).…”

“…Inappropriate planting in rangelands and savanna woodlands Different processes maintain ecosystem health in forests and grasslands, where fire and mega-herbivores underpin community dynamics 8,11 . Restoration programmes often fail to distinguish ancient intact savannas 8,11 or else have miscalculated the amount of natural tree cover already occurring in many dryland areas 88 (Figure 2D). Thus, without proper spatial planning, well-intentioned but blanket restoration treatments can cause significant damage by failing to account for ecosystem characteristics 89 (Box 3).…”

“…Yet many previous well-supported restoration attempts have failed. Government-backed tree expansion programmes from Chile to Cambodia have, at times, backfired on climate, biodiversity, and livelihood goals [6][7][8][9][10] . Multi-billion dollar programmesfrom the pan-African 'Great Green Wall' initiative to China's 'Grain-for-Green' programme (Figure 1A,B) -are now attracting scrutiny for the potential unintended ecological and social consequences they might cause 8,11,12 and the risk of under-delivery 13,14 .…”

“…Government-backed tree expansion programmes from Chile to Cambodia have, at times, backfired on climate, biodiversity, and livelihood goals [6][7][8][9][10] . Multi-billion dollar programmesfrom the pan-African 'Great Green Wall' initiative to China's 'Grain-for-Green' programme (Figure 1A,B) -are now attracting scrutiny for the potential unintended ecological and social consequences they might cause 8,11,12 and the risk of under-delivery 13,14 . The danger is that these well-intentioned programmes plant inappropriate species (the wrong tree, in the wrong place 15 ), marginalise the needs of local people, exacerbate gender and wealth inequalities, and further degrade ecosystems through displacement of agriculture and associated habitat clearance.…”