Survival first, biomass later: trade‐offs shaping dryland restoration outcomes in a Sahelian landscape

Abstract Introduction Land degradation severely constrains livelihoods and ecosystem services across the Sahel. Restoration initiatives commonly combine soil and water conservation (SWC) structures with plantings of native woody species, yet outcomes remain highly variable. Objectives We quantified tree survival and aboveground biomass (AGB) across restored sites and tested how SWC structures, geomorphology, post‐planting management, and planted‐species diversity shape restoration performance and trade‐offs between establishment and productivity. Methods We inventoried 2097 trees from six native species across 14 restored sites in three villages of the Tahoua region (Niger). AGB was estimated using allometric models. Drivers of survival and biomass were analyzed using Bayesian logistic and log‐normal models, including SWC type, geomorphological unit, management regime, and species diversity. Results Survival and biomass were driven by distinct factors. Survival was primarily controlled by management: sites combining guarding, maintenance, and replanting showed the highest survival, whereas weakly managed or unmanaged sites had high mortality. Biomass was mainly determined by SWC structures: trenches, half‐moons, and stone bunds increased biomass, with the strongest effects for trenches. Diversity increased biomass but not survival, and geomorphology played a secondary role. These contrasting responses reveal clear survival–biomass trade‐offs. Conclusions Restoration outcomes in Sahelian drylands are structured by trade‐offs between survival and biomass. Survival depends mainly on management, whereas biomass depends mainly on SWC structures that enhance resource availability.