In the 4th edition of our “Amsterdam Paleoecology Club”(APC), we discussed ‘A 6900-year history of landscape modification by humans in lowland Amazonia’ by Bush et al. (2006)1. The high-resolution record presented in this paper shows impressively that what we might perceive as native rainforest today could rather be a since a long time actively modified landscape.
The chronology from Lake Sauce (Peruvian Andes) suggests a continuously forested landscape under significant anthropogenic impact over the last 6900 years. Indicators of human activity are taken to be the varying presence of crop pollen (Zea mays) throughout the record, combined with the continuous occurrence of charcoal. Two extra-large fire events are dated at c. 6700 and between 4500-4230 cal BP, probably enhanced by the relatively drier climate of the mid-Holocene. However, it is not clear yet if human actions formed a response to climate change or were part of social and cultural changes.
Scales of change (ecological, geological, and human).
Humans as drivers of environmental change.
Extra-terrestrial forcing of environmental change.
Earth system feedbacks.
The week was completed with each student giving a three (3) minute presentation of their favourite paper. The papers presented ranged from the extinction of giant sharks, through forest-savannah transitions, to how climate change thwarted Ghengis Kahn. Next week we continue by disecting how chronologies are constructed.