SOIL DEGRADED BY ALLUVIAL GOLD MINING IN THE PERUVIAN AMAZON:
CLASSIFICATION APPLYING SOIL TAXONOMY (2014) AND WRB (2015)
Abstract
Alluvial gold mining in the Peruvian Amazon has become a key driver of
land degradation and deforestation. In the Madre de Dios region, known
as “the capital of the Peruvian biodiversity”, more than 95,750 ha of
old growth forest were degraded in the las twenty years, at the rate of
6000 ha every year. In Fortuna Community, located in this region of the
Peruvian Amazon, we classified soils of mine spoils and compared them
with nearby soil profiles of undisturbed old growth forest, founding
that both impacted and non-impacted soils are young soils classified as
Fluvisols and Regosols according to the WRB system (2005) and Entisols
according to Soil Taxonomy (2014). Soils of mine spoils have low plant
cover, low fertility, strong acidity, low cation exchange capacity, and
high content of rock fragments in impacted soils; so the impacts on
soils are remarkable decreasing the fertility and soil productivity
compared to non-impacted soils. However, impacted soils are being
improved as time passes by natural regeneration, interaction between
plants and animals, pluvial precipitation and flooding that improve soil
characteristic like organic soil matter and cation exchange capacity,
developing a new soil. In spite there is limited information about these
soils in the Amazon, this research contributes to characterized certain
impacted sites in order to support making decision on how to best
reclaim, rehabilitate or restore these Amazon ecosystems.