Sparse Pre-Columbian Human Habitation in Western Amazonia

Whether similar pre-Columbian impacts occur deep within the interior forests and across most of the basin remains unknown.

“Whether similar impacts occur deep within the interior forests and across most of the basin remains unknown [9,10].”

The overall extent to which lowland Amazonia was actively transformed into a modified landscape or cultural parkland by native people remains unknown and debated.

“However, the overall extent to which lowland Amazonia was actively transformed into a modified landscape or cultural parkland by native people remains unknown and debated [6-10].”

Pre-Columbian impacts across Amazonia were heterogeneous, both in space and degree.

“A newly emerging view is that pre-Columbian impacts across Amazonia were heterogeneous, both in space and degree [9,10].”

Most soil surveys in the westernmost and interfluvial forests contain no evidence of terra pretas.

“Less is known of terra preta occurrence in the westernmost and interfluvial forests, though most soil surveys in these areas contain no evidence of terra pretas [10,33-38] (figure 1).”

Other Amazonian soil surveys also report no evidence of terra preta.

“Other Amazonian soil surveys [10,37,40] also report no evidence of terra preta .”

In much of western Amazonia, human activity was heterogeneous, localized and low-impact, with people sparsely scattered and practicing small-scale clearing and cultivation, except in earthwork-rich areas of southwestern Amazonia.

“although multiple lines of palaeoecological evidence suggest heterogeneous and localized low-impact human activity in much of western Amazonia [10].”

The western, and particularly the northwestern, forests contain limited, if any, evidence of pre-Columbian human presence.

“Consistent with this view, the western, and particularly the northwestern, forests contain limited, if any, evidence of pre-Columbian human presence [10,63].”

The abundance of arboreal phytoliths across Amazonia was significantly and positively correlated with biomass estimates (R = 0.62, p = 8.2e-05).

“The abundance of arboreal phytoliths across Amazonia was significantly and positively correlated with biomass estimates (R = 0.62, p = 8.2e-05)”

Amazonian soil studies reconstructed as forested have rare Poaceae (except Bambusoideae), as do associated modern surface phytolith assemblages from censused vegetation.

“What has been reconstructed as forested in Amazonian soil studies from other regions analyzed also have rare Poaceae (except Bambusoideae), as do associated modern surface phytolith assemblages from censused vegetation (McMichael et al. 2012b; Piperno et al. 2021).”

The forested sites in Suriname have lower arboreal phytoliths than the forest plots of Peru, but higher estimated biomass values.

“The forested sites in Suriname have lower arboreal phytoliths than the forest plots of Peru (McMichael et al. 2012b; Piperno et al. 2021), but higher estimated biomass values.”

Published maps identify fewer than two dozen archaeological sites in the Peruvian Amazon.

“Published maps identify fewer than two dozen sites in the Peruvian Amazon [see20: Fig. 123; Fig. 2.2.224: p. 175;25: Map 1;26: Fig. 1].”