From invasion to circular restoration: <i>Prosopis juliflora</i> biochar enhances native drought resilience

Abstract Introduction Global arid ecosystems face unprecedented pressure from climate change‐induced drought and biological invasions. This study addresses the urgent need for sustainable habitat restoration by repurposing invasive biomass to enhance ecosystem resilience against extreme water scarcity. Objective The primary objective was to evaluate the efficacy of biochar derived from Prosopis juliflora as a strategic tool for mitigating drought stress in P. cineraria , a native keystone species. Methods Invasive P. juliflora biomass was converted to biochar via slow pyrolysis at 450°C. A 4‐month greenhouse experiment was conducted utilizing a factorial design (Control, Biochar, Drought, and Biochar + Drought) with a 2% (w/w) biochar application rate. We measured plant functional traits, productivity, soil nutrient availability, and microbial activity. Severe drought stress was strictly maintained via a daily gravimetric approach to prevent fluctuating wet/dry cycles. Results Biochar successfully mitigated drought‐induced suppression in P. cineraria , facilitating a 15.7% increase in plant height and countering a 14.7% drought‐induced biomass loss with a 14.3% increase in total productivity. Furthermore, biochar induced a strategic shift in plant resource allocation, significantly reducing the root‐to‐shoot ratio by 39.4% under drought stress. These plant‐level improvements were associated with substantial increases in soil organic carbon and total nitrogen, which correlated strongly with a 23.9% improvement in microbial biomass carbon (Cmic) under drought conditions. Conclusions Repurposing invasive P. juliflora biomass into value‐added biochar shows potential to enhance native plant performance and soil microbial health under drought. While these findings provide mechanistic insights under controlled conditions, future field‐based trials and long‐term studies are required to evaluate the persistence and ecological effectiveness of this approach. This circular strategy may offer a promising pathway for integrating invasive species management with climate‐resilient restoration in arid ecosystems.