PERMEAB : Effectiveness of protected areas in limiting agricultural encroachment and conserving herbivores in West-Central African savannahs

Effectiveness of protected areas in limiting agricultural encroachment and conserving herbivores in West-Central African savannahs. 
François Mialhe, Anthony Piron, Alexia Le Floch, Sigrid Griffon, Paul Scholte, Roger Prade, Stephane Ondo Ze, Chloé Guerbois, Olivier Pays, Jon Marco Church et al

Abstract : This study examines the long-term effectiveness of protected areas (PAs) in the savannahs of West and Central Africa in resisting agricultural encroachment and conserving large herbivore populations. Using Landsat imagery (1973–2018) and wildlife census data, we evaluated land-use and land-cover change within ten core PAs and their surrounding 60 km buffer zones, focusing on four focal species: african buffalo, roan antelope, hartebeest, and savannah elephant. Results show that core PAs largely retained their natural vegetation, while surrounding landscapes experienced significant agricultural expansion—particularly in unprotected buffer zones. National parks, especially those embedded within connected networks such as the W–Arly–Pendjari complex, demonstrated stronger resistance to land conversion and higher herbivore biomass. However, wildlife population trends did not consistently align with landscape integrity, indicating that factors such as PA size, governance, and ecological connectivity critically shape conservation outcomes. We identify three typologies of PAs—underperforming large reserves, integrated transboundary networks, and small but well-managed sites—each requiring distinct strategic approaches. These findings underscore the need for outcome-focused conservation strategies that go beyond legal designation to address spatial planning, connectivity, and local management capacity.