Ancient Amazonian populations left lasting impacts on forest structure

Academic Article

Abstract

  • AbstractAmazonia contains a vast expanse of contiguous tropical forest and is influential in global carbon and hydrological cycles. Whether ancient Amazonia was highly disturbed or modestly impacted, and how ancient disturbances have shaped current forest ecosystem processes, is still under debate. Amazonian Dark Earths (ADEs), which are anthropic soil types with enriched nutrient levels, are one of the primary lines of evidence for ancient human presence and landscape modifications in settings that mostly lack stone structures and which are today covered by vegetation. We assessed the potential of using moderate spatial resolution optical satellite imagery to predictADEs across the Amazon Basin. Maximum entropy modeling was used to develop a predictive model using locations ofADEs across the basin and satellite‐derived remotely sensed indices. Amazonian Dark Earth sites were predicted to be primarily along the main rivers and in eastern Amazonia. Amazonian Dark Earth sites, when compared with randomly selected forested sites located within 50 km ofADEsites, were less green canopies (lower normalized difference vegetation index) and had lower canopy water content. This difference was accentuated in two drought years, 2005 and 2010. This is contrary to our expectation thatADEsites would have nutrient‐rich soils that support trees with greener canopies and forests onADEsoils being more resilient to drought. Biomass and tree height were lower onADEsites in comparison with randomly selected adjacent sites. Our results suggested thatADE‐related ancient human impact on the forest is measurable across the entirety of the 6 million km2of Amazon Basin using remotely sensed data.
  • Authors

  • Palace, Michael
  • McMichael, CNH
  • Braswell, BH
  • Hagen, SC
  • Bush, MB
  • Neves, E
  • Tamanaha, E
  • Herrick, Christina
  • Frolking, S
  • Status

    Publication Date

  • December 2017
  • Published In

  • Ecosphere  Journal
  • Keywords

  • Amazonia
  • Amazonian Dark Earths
  • MODIS
  • ancient people
  • anthrosols
  • drought
  • forest structure
  • maximum entropy modeling
  • pre-Columbian impact
  • terra preta
  • tropical forests
  • Digital Object Identifier (doi)

    Start Page

  • e02035
  • Volume

  • 8
  • Issue

  • 12