Denise Schaan

Pre-Columbian geometric earthworks in the upper Purús: a complex society in western Amazonia

Its an ill wind that blows nobody any good. The combination of land cleared of its rainforest for grazing and satellite survey have revealed a sophisticated pre-Columbian monument-building society in the upper Amazon Basin on the east side of the Andes. This hitherto unknown people constructed earthworks of precise geometric plan connected by straight orthogonal roads. Introducing us to this new civilisation, the authors show that the ‘geoglyph culture’ stretches over a region more than 250km across, and exploits both the floodplains and the uplands. They also suggest that we have so far seen no more than a tenth of it.

New radiometric dates for precolumbian (2000-700 B.P.) earthworks in western Amazonia, Brazil

Abstract In this paper we present new data on the precolumbian geometric ditched enclosures identified in Acre State, western Amazonia, Brazil. Remote sensing and ground survey have revealed 281 earthworks, located mainly on the edges of high plateaus overlooking the river valleys drained by the southeastern tributaries of the Upper Purus River. Excavations have shown that the few existing cultural materials are concentrated on the slopes and in the bottoms of the ditches, as well as on small mounds that were likely remains of houses, whereas the central, flat enclosed areas lack major archaeological features. New radiocarbon dates place the initial stage of earthwork construction as early as ca. 2000 b.p. We suggest that the building of these geometric earthworks may have been a regionally shared phenomenon, especially among the Arawak and the Tacana peoples, who used them for special gatherings, religious activities, and, in some cases, as village sites.

Impact of pre-Columbian “geoglyph” builders on Amazonian forests

Significance Amazonian rainforests once thought to be pristine wildernesses are increasingly known to have been inhabited by large populations before European contact. How and to what extent these societies impacted their landscape through deforestation and forest management is still controversial, particularly in the vast interfluvial uplands that have been little studied. In Brazil, the groundbreaking discovery of hundreds of geometric earthworks by modern deforestation would seem to imply that this region was also deforested to a large extent in the past, challenging the apparent vulnerability of Amazonian forests to human land use. We reconstructed environmental evidence from the geoglyph region and found that earthworks were built within man-made forests that had been previously managed for millennia. In contrast, long-term, regional-scale deforestation is strictly a modern phenomenon. Over 450 pre-Columbian (pre-AD 1492) geometric ditched enclosures (“geoglyphs”) occupy ∼13,000 km2 of Acre state, Brazil, representing a key discovery of Amazonian archaeology. These huge earthworks were concealed for centuries under terra firme (upland interfluvial) rainforest, directly challenging the “pristine” status of this ecosystem and its perceived vulnerability to human impacts. We reconstruct the environmental context of geoglyph construction and the nature, extent, and legacy of associated human impacts. We show that bamboo forest dominated the region for ≥6,000 y and that only small, temporary clearings were made to build the geoglyphs; however, construction occurred within anthropogenic forest that had been actively managed for millennia. In the absence of widespread deforestation, exploitation of forest products shaped a largely forested landscape that survived intact until the late 20th century.

The Nonagricultural Chiefdoms of Marajó Island

The study of the pre-Columbian occupation on Marajo Island dates back to the beginnings of archaeology as a field of inquiry in Brazil during the late nineteenth century. Elaborate funerary vessels, together with other exquisite pottery objects excavated from Marajoara cemetery mounds soon filled museums in Rio de Janeiro and Belem, while short notes and articles published in important journals attracted worldwide attention to the unexpected traits of “civilization” just discovered in the tropics. For decades to come, the origins of the people who built the 10to 12 m-high earthen mounds and the meanings of the decorative designs on their pottery were a matter of speculation. During the first half of the twentieth century, scientists, journalists, and nonprofessional archaeologists visited and excavated the mounds located in the seasonally inundated savannas, disturbing them so much that some were turned into piles of broken sherds mixed with the sediment that had been used for mound construction. A site distribution map published by Helen Palmatary in 1950 indicated the existence of some thirty mounds or mound groups dispersed over an area of roughly 20,000 km, leaving open the possibility that many more were yet to be found. Although funerary practices and mound features were described similarly for all locations and the ceramics were all taken as belonging to the same tradition, the excavators noticed both horizontal and vertical variation in the archaeological record; pottery sub-styles varied across the region and burial practices changed through time (Figure 19.1). A change in research objectives and methodology took place with the arrival of Betty Meggers and Clifford Evans, who carried out the first regional survey on Marajo Island during the late 1940s, providing a comprehensive account of Marajoara culture and previous occupations. Based on ceramic attributes, Meggers and Evans (1957) defined five different archaeological phases for Marajo Island alone. With the exception of the

Uma janela para a história pré-colonial da Amazônia: olhando além - e apesar - das fases e tradições

Neste artigo questionamos a correspondencia, muitas vezes assumida, entre industria cerâmica (fase) e grupo social, argumentando a sua inadequacao no que tange ao entendimento da variabilidade ou mudanca na cultura material. Apresentamos tres estudos de caso para demonstrar que as semelhancas tecnologicas e iconograficas entre conjuntos de artefatos podem corresponder a sociedades totalmente distintas em organizacao sociopolitica e modo de subsistencia; a identificacao de variabilidade estilistica dentro de uma mesma fase pode significar o reconhecimento de limites politicos e identidades socioculturais importantes; e a variabilidade tipologica (principalmente quanto a decoracao), utilizada para definir fases distintas, pode mascarar continuidade cultural e mudancas sociopoliticas dentro de um mesmo territorio.

Reply to Piperno et al.: It is too soon to argue for localized, short-term human impacts in interfluvial Amazonia

We welcome the debate opened by Piperno et al. (1) in response to our recent article (2), and thank the editors of PNAS for the opportunity to reply.nnAlthough acknowledging that we detected localized human impacts in our study area, Piperno et al. (1) downplay the increases in palms observed at the geoglyph sites, stating it’s “unclear” whether humans actively managed the forest in these locations. Independent of one’s opinion about intentionality, we argue that the rapid decline of palms after geoglyph abandonment suggests that their previously high levels were because of much more regular, longer-term human influences than Piperno et al. suggest.nnWe also reemphasize that … nn[↵][1]1To whom correspondence should be addressed. Email: jenny.g.watling{at}gmail.com.nn [1]: #xref-corresp-1-1

Pre-Columbian earth-builders settled along the entire southern rim of the Amazon

The discovery of large geometrical earthworks in interfluvial settings of southern Amazonia has challenged the idea that Pre-Columbian populations were concentrated along the major floodplains. However, a spatial gap in the archaeological record of the Amazon has limited the assessment of the territorial extent of earth-builders. Here, we report the discovery of Pre-Columbian ditched enclosures in the Tapajós headwaters. The results show that an 1800u2009km stretch of southern Amazonia was occupied by earth-building cultures living in fortified villages ~Cal AD 1250–1500. We model earthwork distribution in this broad region using recorded sites, with environmental and terrain variables as predictors, estimating that earthworks will be found over ~400,000u2009km2 of southern Amazonia. We conclude that the interfluves and minor tributaries of southern Amazonia sustained high population densities, calling for a re-evaluation of the role of this region for Pre-Columbian cultural developments and environmental impact.Previous studies of Pre-Columbian earthworks in the Amazon basin have left a gap in the Upper Tapajós Basin (UTB). Here, the authors detect 104 Pre-Columbian earthworks in the UTB, suggesting continuous occupation across southern Amazonia and higher population densities than previously estimated.

The legacy of 4,500 years of polyculture agroforestry in the eastern Amazon

The legacy of pre-Columbian land use in the Amazonian rainforest is one of the most controversial topics in the social1–10u202fand natural sciences11,12.u202fUntil now, the debate has been limited to discipline-specific studies, based purely on archaeological data8, modern vegetation13, modern ethnographic data3 or a limited integration of archaeological and palaeoecological data12.u202fThe lack ofu202fintegratedu202fstudies to connect past land use with modern vegetation has left questions about the legacy of pre-Columbian land useu202fon the modern vegetation composition in the Amazon, unanswered11. Here, we show that persistent anthropogenic landscapes for the past 4,500u2009years have had an enduring legacy on the hyperdominance of edible plants in modern forests in the eastern Amazon. We found an abrupt enrichment of edible plant species in fossil lake and terrestrial records associated with pre-Columbian occupation. Our results demonstrate that, through closed-canopy forest enrichment, limited clearing for crop cultivation and low-severity fire management, long-term food security was attained despite climate and social changes. Our results suggest that, in the eastern Amazon, the subsistence basis for the development of complex societies began ~4,500u2009years ago with the adoption of polyculture agroforestry, combining the cultivation of multiple annual crops with the progressive enrichment of edible forest species and the exploitation of aquatic resources. This subsistence strategy intensified with the later development of Amazonian dark earths, enabling the expansion of maize cultivation to the Belterra Plateau, providing a food production system that sustained growing human populations in the eastern Amazon. Furthermore, these millennial-scale polyculture agroforestry systems have an enduring legacy on the hyperdominance of edible plants in modern forests in the eastern Amazon. Together, our data provide a long-term example of past anthropogenic land use that can inform management and conservation efforts in modern Amazonian ecosystems.Fossil records suggest that the Amazon rainforest in the pre-Columbian era was home to polyculture agroforestry, with multiple annual crops providing subsistence for indigenous groups who shaped the Amazon as early as 4,500u2009years ago.

Contours of the Past: LiDAR Data Expands the Limits of Late Pre-Columbian Human Settlement in the Santarém Region, Lower Amazon

ABSTRACT Recent studies have shown that pre-Columbian societies in the Amazon undertook significant landscape modifications, including earthworks. Our fieldwork has revealed that pre-Columbian settlements in the Santarém Region, Lower Amazon, were not limited to the vicinities of permanent water courses, as formerly often assumed. Instead, numerous archaeological sites, dating from ca. a.d. 1300 up to the time of European colonization in the seventeenth century, have been found in an upland area known as the Belterra Plateau, south of the present-day city of Santarém. These upland sites have been found to be associated with particular features in the landscape: cavities or depressions, known locally as “Poços de Água”. LiDAR data shows that a pattern of non-randomly distributed depressions extends far into the densely forested Tapajós National Forest (Flona-Tapajós), allowing us to suggest that the expansion of inland settlement extended considerably farther to the south than what has previously been established through conventional archaeological fieldwork.

Diversity of Pre-colonial Earthworks in the Brazilian State of Acre, Southwestern Amazonia

ABSTRACT Amazonian earthworks, which are an important testimony to ancient anthropogenic landscape modifications, have a significant variety of structures and sizes, and are found in different geographical and ecological locations that indicate separate time periods, distinct cultural affiliations, and diverse purposes. We introduce data from diverse archaeological earthwork sites, geoglyphs, mound sites, and walled enclosures situated in the interfluves of the Purus River in the Brazilian state of Acre and propose a type definition for these sites. The abundant anthropogenic landscape features and their associated material culture indicate considerable human-induced environmental alterations and diverse earthworking traditions that are characteristic of the region of eastern Acre from at least ca. 2000 b.p. onwards.