I just wrote this note on Faculty of 1000 on the paper (doi:10.1073/pnas.0908925107) I mentioned the other day:

Pre-Columbian agricultural landscapes, ecosystem engineers, and self-organized patchiness in Amazonia
McKey D, Rostain S, Iriarte J, Glaser B, Birk JJ, Holst I, Renard D
Proc Natl Acad Sci U S A 2010 Apr 12  [related articles]

This fascinating study describes how ecological engineers (such as ants, termites, and earthworms) maintained a newly described pre-Columbian agricultural landscape. The authors describe sites along the Guianan coastal plain (in Guyana, Suriname, and French Guiana) where pre-Columbian farmers constructed raised fields in flat, marshy locations.

The paper is particularly interesting because it combines new archaeological evidence in favour of the relatively new, and somewhat controversial, idea of a fairly densely settled pre-Columbian Amazonia with an ecological analysis of i) how spatial self-organization of ecosystems was likely used by pre-Columbian agriculturalists to enhance the yield and resilience of their agriculture system and ii) how these same processes have preserved aspects of the agricultural system during about five centuries of abandonment. This study is also interesting for its demonstration of how ecological memory can maintain patterns produced by past disturbance (whether natural or human), and in its hints of how different types of agriculture that work with biodiversity could possibly be reinvented today.

Some photos from the supplementary info of the paper:

Pre-Columbian raised fields in the Guianas. (A–D) Pre-Columbian raised fields in coastal French Guiana are located in flooded depressions, in flat savannas, along sandy ridges, or in talwegs. (A) Piliwa, on the left bank of the Mana River in extreme western French Guiana. (B) Corossony, on the left bank of the Sinnamary River. (C) K-VIII, west of the city of Kourou, near the Bois Diable site. (D) Maillard, between the town of Macouria and Cayenne Island.

(E) Map of raised-field complexes along coastal Amazonia from eastern Guyana to near Cayenne in French Guiana.