X-FOREST: An Open-Source Drone–Rhizosphere Architecture for Accelerated Reforestation and Soil Regeneration

Severe wildfires of 2024-2025 left over 4 million ha of Mediterranean and boreal forests in a degraded state. Conventional hand-planting methods restore at ≤ 1 ha day⁻¹ team⁻¹ and cost upwards of €3,000 ha⁻¹. This paper presents X-FOREST, an open-hardware platform that couples autonomous dew-harvesting drones with a subterranean sensor-actuator root-mesh. The system is designed to hydrate and seed target plots without external pumps, utilising commodity components at an estimated cost of US $390 node⁻¹. All performance values reported here are simulation-based design targets pending field validation. For a 5x5m proof-of-concept plot, the design targets are to collect 3.2 L night⁻¹ of dew, attain >85% germination of acacia-biochar pellets, and reduce labour hours by > 70% relative to manual management. All schematics, firmware, and datasets will be released under CERN-OHL-S v2 and GPL v3 to encourage community-driven development.