Amazonian exploitation revisited: ecological asymmetry and the policy pendulum

The influence of pre-Columbian human populations on Amazonian ecosystems is being actively debated. The longstandingview that Amazonia was only minimally impacted by human actions has been challenged, and a new paradigmof Amazonia as a “manufactured landscape” is emerging. If such disturbance was the norm until just 500years ago, Amazonian ecosystems could be far more ecologically resilient to disturbance than previously supposed.Alternatively, if the “manufactured landscape” label is an overstatement, then policy that assumes such resiliencemay cause substantial and long-lasting ecological damage. We present paleoecological data suggesting a middlepath, in which some areas were heavily modified, but most of Amazonia was minimally impacted. Bluffs adjacentto main river channels and highly seasonal areas appear to have been the most extensively settled locations. Awayfrom areas where humans lived, their influence on ecosystems was very local. Consequently, we see no evidence suggestingthat large areas at a distance from rivers or in the less seasonal parts of Amazonia were substantially alteredby human activity. Extrapolating from sites of known human occupation to infer Amazon-wide landscape disturbancemay therefore potentially lead to unrealistic projections of human impact and misguided policy.