Degradation, management , and classification of soils from alluvial-gold mine spoils in the Peruvian Amazon

Artisanal and Small-Scale Gold Mining (ASGM) significantly contribute to land degradation in the Amazon, carried out by individual miners or small enterprises with limited capital. This practice exerts increasing pressure on biodiversity-rich forests. Due to limited information on edaphic conditions crucial for the restoration of these degraded areas, we employed a soil evaluation method in representative sites of the Peruvian Amazon, including two native communities and one protected natural area. The categorization of ASGM degraded areas into Cultural Landscape Units (CLUs) was confirmed and validated. Sentinel-2 and UAV remote sensing revealed over 122,000 ha deforested since the 1980s. Surface and soil profile assessments identified extreme new soil conditions with low chemical and physical fertility, characterized by coarse texture and rock fragments, hindering revegetation, especially during prolonged drought seasons. These degraded soils were classified as Entisols and Technosols according to Soil Taxonomy and the World Reference Base, respectively. Over time, natural regeneration and plantations improved soil formation, aligning with recognized soil classification systems. Given the current management practices, restoration planning should prioritize selected shrub and tree species, considering soil amendments to initiate soil recovery. This approach aligns with self-sustained successional stages and contributes to the objectives of Land Degradation Neutrality (LDN), Appropriate Mitigation and Adaptation Actions (NAMAs), and Sustainable Development Goals (SDGs).