Terras pretas: Approaches to formation processes in a new paradigm

Abstract

Terras pretas (Amazonian Dark Earths) are a remarkable kind of archaeological site found in the Amazon region. Rich in cultural artifacts and other occupational debris, these dark anthropogenic soil matrices are very fertile, presenting high levels of organic carbon, phosphorus, calcium, magnesium, zinc, and manganese. Their high nutrient levels come from decomposed organic matter, including remains of fish, shellfish, game, and other refuse, while their dark color has been linked to residual charcoal from intentional fires associated with daily activities and landscape management. Studies of anthropogenic earths in the Amazon have a deep history, as much in the geosciences as in archaeology and other historical sciences. Terras pretas have been studied as evidence of a major shift in human–environment relations, but also within the lens of environmental resiliency and sustainability. We review representative studies from various disciplinary fields and trace the development of knowledge about terra preta. We present a growing consensus with regard to the origin and significance of anthropogenic soils, concomitant with increased efforts toward interdisciplinary study. We argue that terras pretas constitute a genuinely interdisciplinary research topic that bridges scientific and traditional knowledge and applied contexts.

Anthropogenic Soils Promote Biodiversity in Amazonian Rainforests

“…Soil provides chemical and physical support for vegetation, and as millennia of human activities created ADEs in the Amazon, this generated patches of higher contents of nutrient and organic resources in a matrix of poorer soils 35 . The formation processes and human management of these soils results in distinct plant and microbial communities 6,9,13,14 .…”

“…As archaeological sites, ADEs are protected by Brazilian law 44 , but throughout Amazonia they are intensively used for agricultural and horticultural purposes 35,45,46 . Soil macrofauna are threatened by modern land use change (particularly intensive annual cropping and livestock production), independently of the soil type.…”

Anthropogenic landscapes of Amazonia : a spatial analysis of landscape modification and settlement organization at Macurany, Brazil.

“…Amazonian landscapes in particular have been viewed from a number of different perspectives, including landscape as an ecological habitat (Steward 1946;Lathrap 1970;Meggers 1971;Erickson 2010;Lombardo and Prümers 2010;Rostain 2013;Kern et al 2017;Watling et al 2017), in terms of patterns of settlement and subsistence (Lathrap 1977;Roosevelt 1980;Roosevelt 1991;Hecht 2003;Walker 2008;Schaan 2008;Oyuela-Caycedo 2008;Heckenberger 2008;Heckenberger et al 2014;Schmidt et al 2018;), and as cosmological and performative spaces (Heckenberger 2005;Gaspar et al 2008; Schaan 2011;Iriarte et al 2013).…”

“…This is especially important for understanding Amazonian landscapes, where subsistence systems are much more complex due to the abundance of microhabitats spread across the landscape. Studying settlement patterns and subsistence systems in combination illuminates aspects about politics and trade (Heckenberger et al 2017) and provides a clearer understanding of ancient resource management (Schaan 2008;Oyuela-Caycedo 2008;Carson et al 2015), landscape formation processes (Hecht 2003;Schmidt et al 2014;Browne Ribeiro 2017;Kern et al 2017), and social organization at local and regional scales in Amazonia (Walker 2008;Heckenberger 2008;Clement et al 2015;Heckenberger 2018).…”

“…Middens and terra preta formed at Macurany through intensive deposition, and likely, processes of internal settlement restructuring and reorganization. Although the creation of terra preta was most likely intentional based on the literature regarding the formation of these landscape features (Browne Ribeiro 2017;Kern et al 2017), the intentionality of the middens at Macurany cannot be confirmed based on surface morphology alone.…”