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