Morgan Schmidt | Universidade Federal de Santa Catarina - UFSC (Federal University of Santa Catarina) (original) (raw)

Publications by Morgan Schmidt

Nature Sustainability, 2024

Amazonian dark earth (ADE) is highly nutrient-and carbon-rich soil created by past inhabitants of... more Amazonian dark earth (ADE) is highly nutrient-and carbon-rich soil created by past inhabitants of the Amazon. It would be valuable to know the extent of ADE because of its cultural and environmental importance, but systematic efforts to map its distribution and extent are impractical with traditional field methods. We use remote sensing imagery and a machine-learning classifier with ground-truthed training data to predict the occurrence of ADE across the 26,000 km 2 Território Indígena do Xingu (TIX) in the southeastern Amazon region of Brazil. We find widespread ADE across the TIX, well beyond previously studied archaeological sites, occupying at least 3-4% of the land area. We further estimate that the TIX may sequester 9 Mt of carbon within ADE deposits from past human inputs. Our findings show that ancient inhabitants of the TIX substantially modified their environment, highlighting the importance of conserving this natural and cultural resource given threats from climate change and deforestation.

Resumos XXII Congresso da SAB, 2023

O tamanho das antigas populações humanas e a extensão do seu impacto na paisagem são intensamente... more O tamanho das antigas populações humanas e a extensão do seu impacto na paisagem são intensamente debatidos na Amazônia. No centro deste debate está a terra preta – solo anómalo caracterizado por uma cor mais escura, teor elevado de carbono orgânico e maior fertilidade do que os solos típicos da Amazônia. Evidências arqueológicas indicam que a terra preta se formou em associação com a ocupação humana, mas é incerto quais práticas criaram a terra preta e se os humanos a criaram intencionalmente. A quantidade de carbono armazenada em locais de terra preta também é em grande parte desconhecida, acrescentando incerteza aos potenciais impactos climáticos da perda de carbono do solo devido a alterações no uso da terra e ao aquecimento global. Demonstramos semelhanças entre a terra preta em contextos antigos e modernos e documentamos práticas indígenas modernas que enriquecem o solo, que usamos para propor um modelo para a formação da terra preta no passado. Esta comparação sugere que os antigos amazônicos manejavam o solo para melhorar a fertilidade e aumentar a produtividade dos cultivos. Estas práticas também sequestraram e armazenaram carbono no solo durante séculos, e mostramos que o conteúdo de carbono orgânico de alguns locais antigos de terra preta é comparável ao da biomassa da floresta. Nossos resultados demonstram a criação intencional da terra preta no Alto Xingu e destacam o papel das antigas interações homem-paisagem na formação dos reservatórios terrestres de carbono.

Nature Ecology & Evolution, 2024

The expansion of globalized industrial societies is causing global warming, ecosystem degradation... more The expansion of globalized industrial societies is causing global warming, ecosystem degradation, and species and language extinctions worldwide. Mainstream conservation efforts still focus on nature protection strategies to revert this crisis, often overlooking the essential roles of Indigenous Peoples and Local Communities (IP&LC) in protecting biodiversity and ecosystems globally. Here we assess the scientific literature to identify relationships between biodiversity (including ecosystem diversity) and cultural diversity, and investigate how these connections may affect conservation outcomes in tropical lowland South America. Our assessment reveals a network of interactions and feedbacks between biodiversity and diverse IP&LC, suggesting interconnectedness and interdependencies from which multiple benefits to nature and societies emerge. We illustrate our findings with five case studies of successful conservation models, described as consolidated or promising ‘social–ecological hope spots’, that show how engagement with IP&LC of various cultures may be the best hope for biodiversity and ecosystem conservation, particularly when aligned with science and technology. In light of these five inspiring cases, we argue that conservation science and policies need to recognize that protecting and promoting both biological and cultural diversities can provide additional co-benefits and solutions to maintain ecosystems resilient in the face of global changes.

Download partial pdf of only Xingu related parts of article.

Papers of the Applied Geography Conferences, 2012

Tradução de: LANDSCAPES OF MOVEMENT IN AMAZONIA: NEW DATA FROM ANCIENT SETTLEMENTS IN THE MIDDLE ... more Tradução de: LANDSCAPES OF MOVEMENT IN AMAZONIA: NEW DATA FROM ANCIENT SETTLEMENTS IN THE MIDDLE AND LOWER AMAZON

Science Advances, 2023

Fertile soil known as Amazonian dark earth is central to the debate over the size and ecological ... more Fertile soil known as Amazonian dark earth is central to the debate over the size and ecological impact of ancient human populations in the Amazon. Dark earth is typically associated with human occupation, but it is uncertain whether it was created intentionally. Dark earth may also be a substantial carbon sink, but its spatial extent and carbon inventory are unknown. We demonstrate spatial and compositional similarities between ancient and modern dark earth and document modern Indigenous practices that enrich soil, which we use to propose a model for the formation of ancient dark earth. This comparison suggests that ancient Amazonians managed soil to improve fertility and increase crop productivity. These practices also sequestered and stored carbon in the soil for centuries, and we show that some ancient sites contain as much carbon as the above-ground rainforest biomass. Our results demonstrate the intentional creation of dark earth and highlight the value of Indigenous knowledge for sustainable rainforest management.

The Holocene, 2023

The nature and extent of past indigenous transformations in the Amazon basin is an actively debat... more The nature and extent of past indigenous transformations in the Amazon basin is an actively debated topic, and one that has important implications for both conservation policy and the cultural heritage of its indigenous and traditional populations. The use of charcoal and phytoliths to measure past human impacts in non-lacustrine settings has become especially influential in this debate but has also generated disagreement among scholars regarding the possible limits of these proxies for detecting ancient land-use. To contribute empirical data to this issue, our paper presents the first attempt to study charcoal and phytolith signals from areas of modern indigenous land-use, in the Xingu Indigenous Territory, southern Amazonia. Our findings show that, while charcoal and early successional herb phytoliths are good indicators of land-use intensity, certain types of land-use leave subtler traces in the phytolith record that can hinder their detection. We demonstrate how using finer sampling resolution and comparing local proxy data on their own terms are necessary steps in order to identify trends in human land-use across time and space.

Nature Communications, 2022

JGR Earth Surface, 2021

Large alluvial rivers transport water and sediment across continents and shape lowland landscapes... more Large alluvial rivers transport water and sediment across continents and shape lowland landscapes. Repeated glacial cycles have dominated Earth's recent climate, but it is unclear whether these rivers are sensitive to such rapid changes. The Amazon River system, the largest and highest discharge in the world, features extensive young terraces that demonstrate geologically rapid change temporally correlated with changes in runoff from Quaternary climate cycles. To test the plausibility of a causal relationship, we use a simple model to estimate from empirical measurements how quickly a river profile responds to changes in discharge or sediment supply. Applying this model to data from 30 gauging stations along alluvial rivers throughout the Brazilian Amazon, we find that many rivers of the Amazon basin can respond faster than glacially induced changes in runoff or sediment flux. The Amazon basin
is unusually responsive compared to other large river systems due to its high discharge and sediment flux, narrow floodplains, and low slopes. As a result, we predict that the Amazon basin has been highly dynamic during Quaternary glacial cycles, with cyclical aggradation and incision of lowland rivers driving repeated habitat and environmental change throughout the region. This dynamic landscape may have contributed to the exceptional biodiversity of the region and patterns of ancient human settlement.

Boletim do Museu Paraense Emilio Goeldi: Ciencias Humanas, 2019

Resumo: Segundo estudos recentes, a influência indígena sobre a floresta amazônica foi intensa, d... more Resumo: Segundo estudos recentes, a influência indígena sobre a floresta amazônica foi intensa, diversificada e teve início com a chegada do Homem na região, nos primórdios do Holoceno inferior. Nesta história de longa duração, no entanto, a seleção cultural de espécies úteis promovidas não foi uma via de mão única. Ela impactou a seleção natural, quando muitas espécies foram distribuídas geograficamente pelas sociedades humanas, resultando em um importante capital para as gerações futuras. Por outro lado, essas mesmas sociedades tiveram suas escolhas, suas técnicas e seus costumes influenciados pelas espécies selecionadas. Isso quer dizer que durante a acumulação desse capital ocorreu uma inter-relação entre a cultura e a natureza, de modo que ambas se desenvolveram e/ou evoluíram conjuntamente. Em Carajás, no Pará, temos evidências de que, além da inter-relação Homem/natureza, cujos efeitos podem ser notados muito além dos espaços arqueológicos circunscritos pela mera distribuição da cultura material, as sociedades pioneiras que lá viveram foram capazes de transformar os ambientes explorados em paisagens domesticadas, ricas em recursos, o que ocorreu segundo uma alteridade social de longa persistência, com diferentes períodos de desenvolvimento cultural, favorecendo o surgimento de processos históricos contíguos, mas diferentes, que foram territorialmente amplos e cada vez mais complexos.

Palavras-chave: Sociedade. Amazônia. Paisagens antropogênicas. Holoceno inferior. Cultura Tropical.

Abstract: Archeology and other sciences increasingly affirm that indigenous influence on the Amazon rainforest has been intense and diversified, beginning with the arrival of humans by the Lower Holocene. But cultural selection of useful species was not a one-way street during this long history; instead, geographic distribution by human societies affected natural selection. These choices and customs of these societies were consequently influenced by the selected species, resulting in important capital for future generations. As a result, there has been a long-term relationship or coevolution between culture and nature; in other words, during the accumulation of this capital an interrelationship between culture and nature took place, with both developing and/or evolving together. This contradicts the idea that these societies were simple hunter-gatherer groups with no history whose characteristics and cultures were determined by the natural availability of subsistence resources. In Carajás (Pará State) we have evidence that in addition to the interplay between humans and nature (the effects of which can be seen in vegetation beyond the areas where the material culture is found), early societies were able to transform environments to construct resource-rich domesticated landscapes.

A Humanidade e a Amazonia: 11000 Anos de Evolução Histórica em Carajás, 2018

Sedimentos e solos antrópicos formam-se quando atividades humanas modificam solos e/ou transform... more Sedimentos e solos antrópicos formam-se quando atividades humanas modificam solos e/ou transformam ou criam camadas estratigráficas de sedimentos. Os estudos dos sedimentos e solos antrópicos vêm se desenvolvendo desde a descober ta de que teores de fósforo e outros elementos, matéria orgânica e o pH podem ser elevados nas áreas onde haviam antigos assentamentos, caminhos ou roças. Isso chamou a atenção dos arqueólogos e outros cientistas para o potencial das análises químicas e físicas de sedimentos e solos nos estudos sobre o passado humano.

Latin American Antiquity, 2016

Increasingly, archaeological research in Amazonia is revealing complex precolonial occupation in ... more Increasingly, archaeological research in Amazonia is revealing complex precolonial occupation in areas around riverine confluences. In 2014, the first site-based archaeological investigations were undertaken in Gurupá, Pará, Brazil, a municipality that spans the region of the Xingu-Amazon confluence. The Portuguese controlled access to Amazonia from 1623 onward through a network of settlements organized around Gurupá. Results from extensive excavations of terra preta sites, landscape archaeology, and analysis of ceramic evidence suggest that this was also a precolonial crossroads. Carrazedo, once a booming historical town (Arapijó), sits atop a significantly larger terra preta site. Excavations in historical and pre-colonial sectors of Carrazedo found well-preserved remains, including a precolonial house terrace complex. The extent of terra preta and earthworks at Carrazedo indicate that the precolonial occupation was more intensive than the colonial-historical period occupation. Regional survey revealed colonial-historical period sites consistently overlying expansive pre-colonial sites, the density and extent of which suggest a major precolonial center at the Xingu-Amazon confluence. Overall, ecological and landscape modifications appear to have been more intense in the precolonial past than during later periods. Short-and long-distance settlement networks also differed during the two periods. This as-of-yet understudied region promises to shed new light on deep-time human-environment interactions and spatial organization in the humid tropics of Amazonia. Cada vez mais pesquisas arqueológicas na Amazônia têm revelado ocupações pré-coloniais complexas nas confluências de grandes rios. Em 2014, foram desenvolvidas as primeiras investigações arqueológicas acadêmicas em Gurupá/Pará/Brasil, um município localizado na confluência dos rios Xingu e Amazonas. Entre os séculos XVII e XIX, os Portugueses controlaram o acesso à Amazonia através de uma complexa rede de assentamentos organizada no entorno de Gurupáá. Extensos sítios de Terra Preta, assim como evidências da paisagem e da cerâmica sugerem que este local foi uma importante encruzilhada também no período pré-colonial. Carrazedo, uma importante cidade histórica (Arapijó) está situada sobre um grande sítio de Terra Preta. Escavações nos setores histórico e pré-colonial no sítio evidenciaram vestígios em boas condições de preservação, inclusive um complexo de terraços associados à atividades domésticas. A extensão da terra preta e das áreas que envolvem construções e movimentações de terra sugerem que a ocupação pré-colonial foi mais intensa do que a ocupação colonial/histórica. Levantamentos regionais revelaram que os sítios de habitação históricos e contemporâneos se sobrepõem a extensos sítios pré-coloniais, cuja densidade e tamanho sugerem a existência de importantes centro culturais pré-coloniais na confluência dos rios Xingu e Amazonas. De modo geral, as modificações ecológicas e construções paisagísticas parecem ter sido mais intensas no passado pré-colonial do que nas ocupações históricas subsequentes, e resultados preliminares das análises espaciais e cerâmicas apontam diferenças nas redes de assentamentos locais e regionais relacionadas a estes dois períodos distintos. Assim sendo, esta região pouco estudada se mostra promissora para investigações sobre a história profunda da Amazônia, organização espacial e as interações homem-ambiente nos trópicos húmidos.

Amazonia Antropogenica, 2016

No século XIX, viajantes na Amazônia ficaram fascinados pelas extensas áreas de terra preta, c... more No século XIX, viajantes na Amazônia ficaram fascinados pelas extensas áreas de terra preta, cheias de cerâmica e outros artefatos atribuídos a assentamentos abandonados. Charles Hartt e Herbert Smith observaram a presença de terra preta em muitos lugares na região do baixo Tapajós. Smith diz que o solo fértil era “o melhor da Amazônia” e “deve sua riqueza ao lixo de mil cozinhas por talvez mil anos”. Ele relata que cana de açúcar, tabaco, guaraná, milho, algodão e outros eram “cultivados nas ricas terras pretas ao longo dos barrancos onde os índios tiveram suas aldeias há muito tempo atrás... a terra preta é quase continua... em muitos lugares cerâmica e instrumentos de pedra cobrem a superfície como conchas em uma praia lavada pelo mar”. Até hoje, diversos habitantes na Amazônia reconhecem a alta fertilidade de terra preta e as utilizam para plantar diversos cultivos. Para cientistas e outros, o que chama atenção nestes solos é a sua extraordinária fertilidade e resiliência com altas concentrações de carbono e nutrientes em uma região conhecida pela baixa fertilidade de seus latossolos para a agricultura.

Amazonia Antropogenica, 2016

Journal of Archaeological Science, v. 42, p. 152-165, Feb 2014

Ancient anthrosols known as Amazonian dark earths or terra preta are part of the human built land... more Ancient anthrosols known as Amazonian dark earths or terra preta are part of the human built landscape and often represent valuable landscape capital for modern Amazonian populations in the form of fertile agricultural soils. The fertility, resilience, and large stocks of carbon in terra preta have inspired research on their possible role in soil fertility management and also serve as an example for a growing biochar industry it is claimed will sequester carbon for climate change mitigation. Although there is considerable scientific and public interest in terra preta, there is still much debate and little concrete knowledge of the specific processes and contexts of its formation. Research indicates that the formation of terra preta occurred mainly in midden deposits, themselves patterned around habitation areas, public areas, and routes of movement. Data from topographic mapping, soil analyses, and excavations in three regions of Amazonia demonstrate a widespread pattern of anthrosol formation in ring-shaped mounds surrounding flat terraces that extend across large areas of prehistoric settlements. It is hypothesized that there is a widespread type or types of occupation where the terraces were domestic areas (houses or yards) surrounded by refuse disposal areas in middens which built up into mounds over time, forming large deposits of terra preta and creating what could be called a ‘middenscape.’ Initial results support the hypotheses, showing the interrelationship of residential and public areas, anthrosols, routes of movement, and natural resources. The patterning of anthrosols in ancient settlements indicates the use of space and can therefore serve as a basis for comparison of community spatial organization between sites and regions.

Antes de Orellana. Actas del 3er Encuentro Internacional de Arqueología Amazónica, May 2014

Anthrosols known as Amazonian Dark Earths (ADE) or terra preta are part of the ancient human buil... more Anthrosols known as Amazonian Dark Earths (ADE) or terra preta are part of the ancient human built landscape that formed from repeated actions by individuals over time. These fertile soils formed in and around indigenous settlements through a diversity of actions such as the discard of organic and solid refuse, burning, and soil management for crop cultivation. Terra preta formed from the deposition of organic and solid materials that was patterned by the use of space within settlements. This article presents data from topographic mapping, soil analyses, and excavations to demonstrate a widespread pattern of terra preta formation documented in three regions. The pattern consists of curvilinear mounds of terra preta surrounding flat terraces that extend across large areas of prehistoric settlements. The objective of the present research is to investigate the processes that formed archaeological sites with anthrosols and better understand the use of space and resources in ancient Amazonian settlements.

Boletim do Museu Paraense Emílio Goeldi, v. 8, no. 1, 2013

Fertile dark anthrosols associated with pre-Columbian settlement across the Amazon Basin have spa... more Fertile dark anthrosols associated with pre-Columbian settlement across the Amazon Basin have sparked wide interest for their potential contribution to sustainable use and management of tropical soils and ecosystems. In the Upper Xingu region of the southern Amazon, research on archaeological settlements and among contémporary descendent populations provides critical new data on the formation and use of anthrosols. These findings provide a basis for describing the variability of soil modifications that result from diverse activities and a general model for the formation of Amazonian anthrosols. They underscore the potential for indigenous systems of knowledge and resource management to inform efforts for conservation and sustainable development of Amazonian ecosystems.

Papers of the Applied Geography Conferences v. 35, 2012

Ancient built landscapes including roads, earthworks, and patches of fertile anthrosols have been... more Ancient built landscapes including roads, earthworks, and patches of fertile anthrosols have been documented in several areas of the South American lowlands representing landscape capital that is often utilized by succeeding generations. Recent research is uncovering substantial human modified landscapes in the vicinity of ancient settlements in the Middle and Lower Amazon. Anthropogenic landscape features indicate routes of human movement within settlements and between settlements and local resources. Formation of anthrosols known as terra preta is patterned around habitation areas, public areas, and routes of movement. This research investigates topographic features and anthrosols to learn how their patterning on the landscape indicates the structure, use of space, and resource use in ancient settlements. Archaeological excavations and mapping show the relationship of settlements, anthrosols, routes of movement, and natural resources. Results demonstrate substantially modified human landscapes with features that have permanently transformed what is too often considered pristine nature in Amazonia.

Arqueologia Amazonica II, 2010

Pedoarchaeological studies have demonstrated correlations between activity areas and anthropical... more Pedoarchaeological studies have demonstrated correlations between activity areas and anthropically modified soils at habitation sites. The results presented here confirm that this correlation exists in modern and historic indigenous villages and ancient settlements in the Upper Xingu region. Soil samples from different activity areas from these contexts as well as off-site areas were analyzed for a series of chemical properties including pH in water, organic C (Walkley-Black), Al, Ba, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Sr, Ti, V, and Zn. A total digestion of approximately 0.1 g of soil was performed in a microwave-acid digestion and measured with ICP OES. The objective was to characterize the activity areas by the chemical properties of the soil in an attempt to identify soil chemical signatures for the different areas. To do this, discriminant analyses were carried out with the data. The results show significant differences between the different activity areas and some of the factors and processes that contribute to the formation of Amazonian anthrosols known as terra preta.

Amazonian Dark Earths: Wim Sombroek’s Vision, 2009

Amazonia is a region known for large expanses of acid, infertile soils difficult to farm without ... more Amazonia is a region known for large expanses of acid, infertile soils difficult to farm without considerable inputs of fertilizer or long fallow periods. In this same region, scattered patches of fertile black soil also exist that are highly sought after by farmers for planting nutrient-demanding crops. These areas are the result of the activities of prehistoric Amerindians. We know that the black earth is associated with archaeological sites and is, in itself, an archaeological remain that is full of information about past societies and their resource use. Scientists also believe that research on black earth, known as terra preta do índio in Brazil, could lead to a better understanding of soils and their management, particularly nutrient-poor tropical soils. Questions remain as to what processes were in action to produce the fertile black soil and what keeps them fertile over long time periods. Archaeological research in the Upper Xingu suggests that Amerindians today continue basic economic forms and settlement patterns from those of the prehistoric inhabitants who left a legacy of large sites with earthworks and abundant terra preta. The apparent cultural continuity makes an ethnoarchaeological approach even more valuable for understanding the archaeology of the region and presents a unique opportunity to address questions about the range of activities that produced the soil variation found in archaeological sites.

The Kuikuro Amerindian word for the black soil is igepe, which is also their word for cornfield. They plant fields of their staple crop manioc on the normal red soils but all other crops are planted on patches of deep terra preta with abundant ceramic fragments and boasting large prehistoric earthworks that give structure to the sites. They plant banana, corn, squash, sweet potato, papaya, sugarcane, and many other crops that generally would not do well in the natural red soil. The fact that they are willing to travel up to 10 km or more to reach these igepe gardens and haul the produce back to the village demonstrates the value of the terra preta to the Kuikuro. They are using a resource that was accumulated over decades or centuries by previous inhabitants but, are they also creating it themselves?

As Terra Pretas de Índio da Amazônia: Sua Caracterização e Uso deste Conhecimento na Criação de Novas Áreas, 2009

Nature Sustainability, 2024

Resumos XXII Congresso da SAB, 2023

Nature Ecology & Evolution, 2024

Download partial pdf of only Xingu related parts of article.

Papers of the Applied Geography Conferences, 2012

Science Advances, 2023

The Holocene, 2023

Nature Communications, 2022

JGR Earth Surface, 2021

Boletim do Museu Paraense Emilio Goeldi: Ciencias Humanas, 2019

Palavras-chave: Sociedade. Amazônia. Paisagens antropogênicas. Holoceno inferior. Cultura Tropical.

A Humanidade e a Amazonia: 11000 Anos de Evolução Histórica em Carajás, 2018

Latin American Antiquity, 2016

Amazonia Antropogenica, 2016

Journal of Archaeological Science, v. 42, p. 152-165, Feb 2014

Antes de Orellana. Actas del 3er Encuentro Internacional de Arqueología Amazónica, May 2014

Boletim do Museu Paraense Emílio Goeldi, v. 8, no. 1, 2013

Papers of the Applied Geography Conferences v. 35, 2012

Arqueologia Amazonica II, 2010

Amazonian Dark Earths: Wim Sombroek’s Vision, 2009

As Terra Pretas de Índio da Amazônia: Sua Caracterização e Uso deste Conhecimento na Criação de Novas Áreas, 2009

This project investigates the formation of prehistoric anthrosols known as terra preta in Brazil.... more This project investigates the formation of prehistoric anthrosols known as terra preta in Brazil. Large and small patches of terra preta are found in diverse environments throughout the Amazon Basin. They are highly sought after by farmers for cultivating a diverse range of crops and have attracted considerable attention by scientists and the media because of their phenomenal fertility in a region dominated by highly weathered, infertile tropical soils. Terra preta soils were formed by human activities and mark the locations of ancient settlements. Some scientists espouse terra preta research as key to increasing sustainability and improving the fertility of tropical soils. However, there is considerable speculation and a paucity of empirical data on the formation processes of these soils.

The state of the knowledge on terra preta is expressed in four recent edited volumes dedicated to the topic (Glaser and Woods 2004; Lehmann et al. 2003; Teixeira et al. 2009; Woods et al. 2009). Two complementary hypotheses are advocated to explain the formation of darkened anthrosols in the Amazon. In the “midden model” the darkest terra preta with abundant ceramics was formed mainly from refuse disposal at habitation sites while in the “cultivation model” agricultural practices introduced ash, charcoal, and organic material into the soil forming brown soils with few ceramics on the periphery of settlements. With these hypotheses comes the question of intentionality versus unintentionality in the formation of the enriched soils. Were ancient Amazonian farmers intentionally making terra preta?

The significance of this research is the ethnoarchaeological context. It was carried out in a contemporary Xinguano (Amerindian) community, the Kuikuro, with historical links to nearby abandoned settlements that have large expanses of terra preta. Working with the community allowed direct observations of activities and soil sample collection from specific activity areas. Little previous research has been carried out in Amazonia in this respect, with several notable exceptions (Hecht 2003, 2009; Hecht and Posey 1989; Heckenberger 1996; Silva 2003; Silva and Rebellato 2004). These few studies provided some intriguing data from observations and a small number of soil samples but this doctoral research is the first to carry out comprehensive soil testing in an ethnoarchaeological context with the objective of documenting terra preta formation processes and characteristics.

Several thousand soil samples were collected from the current Kuikuro village, two historic villages, and three large prehistoric sites. Areas that were defined and sampled included the plaza, house floors, backyards, fire hearths, manioc processing areas, trash middens, fields, fallows, and forest. Soil analyses included particle size, Munsell color, pH, organic carbon (OC), available nutrients, and total elements measured with Inductively Coupled Plasma Optical Emission Spectrometry. The data were subjected to statistical analyses that included basic descriptive statistics and multivariate discriminant analyses. The variables used in discriminant analyses included pH, OC, and total Al, Ba, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Sr, Ti, V, and Zn. Groups of samples from different activity areas were compared with one another and discriminant analysis was employed to examine differences and determine how well groups could be separated and samples correctly classified. It was also determined which variables were most and least effective at separating groups and which combinations of variables could be used most effectively.

The groups were shown to have distinctive “soil signatures” in the current village context. Middens had a high pH, high OC content, the highest enrichments of the greatest range of plant nutrients (Ba, Ca, Cu, K, Mg, Mn, Na, P, Sr, and Zn), and especially low Al, Fe, Ti, and V. Fallow areas on the periphery of the village showed enrichment similar to middens but at much lower magnitudes. Fire hearths had an elevated pH, low OC content, and exceptionally elevated K content. By comparing middens of different ages it was shown that Mn, Ba, and Sr are among the elements, in addition to pH, that stay most fixed in the soil and are therefore especially useful in pedo-archaeological studies. Many of the variables that are typically elevated from human activities were shown to significantly decrease over time in middens from the current and historic villages including pH, OC, Ca, K, Mg, Na, Sr, P, and Zn. The research documented the extreme heterogeneity of the soil in all areas. Discriminant analyses found that most of the variables were useful in separating groups of samples from different areas but several of them consistently performed better while others added relatively little to the separating power of the discriminant functions. In an analysis using six groups (Fallow Area, Fire hearth, Forest, Manioc Processing, Mid-plaza, and Midden), the ordering of the 15 most effective variables was the following: pH, Ba, Fe, Ti, V, OC, Sr, P, Ca, Mg, Zn, Mn, Co, Al, and K. The five variables that were the least “powerful” included Cr, Cu, Na, Ni, and Pb. A significant result was that pH came out at or near the top in every analysis and also remained at similar levels in historic and prehistoric middens. This is an intriguing result since pH analysis is fast and easy to perform, can be done in the field, and requires no expensive equipment or reagents.

The results of soil analyses and ethnographic observations support the hypotheses set forth by previous researchers and offer further details. Bulky organic refuse, namely waste from manioc processing, is preferentially deposited further away from the house while more diverse and durable refuse is deposited closer to the house. In addition to cultivation, the sorting of refuse by type could contribute to the formation of lighter brown soils on the periphery of settlements. I conclude that the bulk of terra preta was formed in middens. Refuse disposal in middens forms a distinctive pattern of linear mounds on the edges of backyards and trails. It is hypothesized that this process formed the linear and ring-shaped mounds observed not only in Upper Xingu prehistoric sites but also in sites in the Central Amazon and Trombetas regions.

Farmers were observed planting a diverse range of crops directly in the middens. They were also observed fertilizing land on the periphery of the village with organic refuse and mulching crops with weeds cleared from within the village. It is clear that they know what they are doing when they enrich soil in the refuse disposal areas and then use it for planting crops.

In addition to refuse disposal, there is a significant anthropic impact on the soil in domestic and public areas. Activity areas are extremely dynamic, shifting over time and forming a palimpsest of human impact on the soil. When the village expands, activity areas shift on top of the middens and middens are sometimes leveled to create a pad for building new houses. These processes were likely responsible for the deep stratified deposits of terra preta found in many prehistoric sites throughout the Amazon.

An examination of agrobiodiversity on the flood plains and adjacent uplands along a stretch of th... more An examination of agrobiodiversity on the flood plains and adjacent uplands along a stretch of the Amazon river (Middle Solimões) illustrates the enormous variability between different land use strategies. Farmers in the region use five principal habitat types for agriculture; beaches, mudflats, low levees, high levees, and uplands. High levees and uplands contain the greatest diversity in both land use types and useful plants. The research revealed 24 designations of land use by local residents when divided along lines of habitat, current status (field or fallow), and management. Home gardens are an important repository of agrobiodiversity because they contain almost the entire spectrum of useful species including many not found in other land use types and almost every home has one.

American Geophysical Union, 2022

Human-landscape interactions have influenced the carbon cycle in numerous ways since the industri... more Human-landscape interactions have influenced the carbon cycle in numerous ways since the industrial revolution, but the role of human activities in the ancient world is less well known. One example is the Amazon region, one of the most important terrestrial carbon reservoirs, where the size of ancient human populations and the extent of their impact on the landscape are hotly debated. Central to this debate is Amazonian dark earth – anomalous soil characterized by darker color, higher organic carbon content, and higher fertility than typical Amazonian upland soils. Archaeological evidence indicates that dark earth formed in association with human occupation, especially on high bluffs created by river entrenchment, but it is uncertain what practices created dark earth and whether humans created it intentionally. The amount of carbon stored in dark earth sites is also largely unknown, adding uncertainty to the potential climate impacts of soil carbon loss due to land-use change and global warming. We demonstrate similarities between dark earth in ancient and modern contexts and document modern indigenous practices that enrich soil, which we use to propose a model for the formation of ancient dark earth. This comparison suggests that ancient Amazonians managed soil to improve fertility and increase crop productivity. These practices also sequestered and stored carbon in the soil for centuries, and we show that the organic carbon content of some ancient dark earth sites is comparable to that of the above-ground rainforest biomass. Our results demonstrate the intentional creation of Amazonian dark earth and highlight the role of ancient human-landscape interactions in shaping terrestrial carbon reservoirs.

Conference presentation: Belem +30 ISE SBEE, 2018

Human activities concentrated nutrients in soils throughout the Holocene in Amazonia. Recent rese... more Human activities concentrated nutrients in soils throughout the Holocene in Amazonia. Recent research in Serra dos Carajás is demonstrating that activities such as burning and refuse disposal resulted in patches of soils and sediments in both cave and open air sites with modified physical and chemical properties up to at least 11,000 years ago. The investigation of these soils and the use of soil analysis in archaeological research have been hampered by the high cost of collecting and analyzing large numbers of samples. To study these soil transformations, alternatives to traditional soil analyses are being tested to measure the degree of human impact on the soil in archaeological sites. Analyses being tested include magnetic susceptibility, electrical conductivity, and portable X-ray Florescence. Once the relatively low-cost instruments are obtained, these analyses are quick, cheap and non-destructive of samples. Results obtained so far using these methods show clear correlations with those from more traditional chemical analyses. They show spatial distributions in soil modifications within archaeological sites that indicate where distinct activities were occurring in the past. This can assist scientists in deciphering the complex archaeological record of occupation sites and show how modification of the soil was a fundamental way in which humans interacted with the Amazonian environment throughout the Holocene.

artigo do 56o Congreso Internacional de Americanistas, 2018

Estudos arqueológicos recentes no sudeste da Amazônia, na região da Serra dos Carajás, vão destac... more Estudos arqueológicos recentes no sudeste da Amazônia, na região da Serra dos Carajás, vão destacando a transformação do meio ambiente por atividades humanas desde o inicio do Holoceno, cerca de 11,000 anos antes do presente. O solo e a vegetação nas áreas onde há vestígios arqueológicos foram modificados pelas atividades domésticas e de manejo no passado. Os impactos nos sedimentos e solos em sítios em cavidades ou a céu aberto, com datas mais antigas ou mais recentes, se refletem nos resultados de análises físicas e químicas que incluíram susceptibilidade magnética, condutividade elétrica, pH, matéria orgânica, Al, P, K, Ca e Mg. Resultados preliminares mostram um impacto significativo nos valores destas variáveis em diferentes áreas dos sítios que refletem os diferentes usos do espaço no passado.

XVI Congresso ABEQUA - abstract, 2017

A susceptibilidade magnética (SM) é a grandeza que representa quantitativamente a resposta magn... more A susceptibilidade magnética (SM) é a grandeza que representa quantitativamente a resposta magnética de um material a um campo magnético aplicado. No solo é influenciada pela mineralogia, quantidade e forma dos minerais, que podem ser classificados, em diamagnéticos, paramagnéticos, ferromagnéticos, ferrimagnéticos e antiferromagnéticos. Estudos arqueológicos utilizam a SM para caracterizar anomalias causada pelo aquecimento, fenômeno denominado de termoremanência, sendo um parâmetro bastante promissor na região tropical pela elevada concentração de minerais que contem ferro em sua composição. Foram avaliadas a SM em amostras oriundas de Trombetas, Carajás, Xingú, Amazônia Central, geoglifos no Acre e sambaquis do litoral do Rio de Janeiro. Os resultados da SM variarão entre 0,021 e 96 x 10-3 SI evidenciando a predominância de minerais diamagnéticos nas amostras quartzo arenosas de Trombetas e a presença de minerais magnéticos nos valores mais elevados encontrados em amostras de Carajás. Os resultados possibilitam a identificação de áreas que apresentam anomalias e evidenciam o potencial de uso para a delimitação da área do sítio. Há necessidade de valores da SM de referência (sem influência antrópica) para a interpretação dos dados.

Society for American Archaeology Annual Meeting, Vancouver B.C., 2017

Short-term, small-scale interactions between humans and the environment may result in profound tr... more Short-term, small-scale interactions between humans and the environment may result in profound transformations of that environment over time. Recent archaeological research in Amazonia has revealed the extent that daily practices, such as refuse disposal or cultivation, have modified the soil in the vicinity of ancient and modern settlements. The fertile anthropic soil known as terra preta, formed mainly through the discard of refuse around habitation areas, is an example of how quotidian actions by humans and other organisms together created these landscapes. These activities have resulted in a widespread pattern where similar features are found in ancient settlements across the broad Amazon region. The landscapes have been documented in several widely spaced areas and in differing environmental and cultural contexts, including large sites along major rivers as well as smaller sites in interfluvial areas. Daily activities resulted in patterns of modified soils and geomorphology that reflect the organization and use of space in settlements. Once these features are formed, they may serve as landesque capital that is repeatedly used by succeeding generations or occupations.

III Reunião da SAB Norte, Porto Velho, Rondonia, Nov 9, 2016

A ocupação humana na Serra dos Carajás, sudeste do Pará, tem pelo menos 11.000 anos. Pesquisas ar... more A ocupação humana na Serra dos Carajás, sudeste do Pará, tem pelo menos 11.000 anos. Pesquisas arqueológicas recentes têm revelado impactos nos sedimentos e solos, em termos das propriedades químicas, desde os sítios mais antigos localizados em grutas e abrigos até outros mais recentes em céu aberto com o solo antrópico escuro conhecido como terra preta. As análises demonstram que há grandes variações nos teores de elementos químicos dentro dos sítios, que provavelmente refletem as diversas atividades que ocorreram neles. Quando utilizado em conjunto com outros dados espaciais de cultura material, a análise química serve como uma forte linha de evidência adicional sobre o uso do espaço nos sítios. Ademais, uma grande vantagem das análises químicas é de fornecer informações sobre atividades humanas em áreas desprovidas de cultura material.

Landscape Archaeology Conference, Uppsala, Sweden, Aug 24, 2016

Short-term, small-scale interactions between humans and the environment may result in profound tr... more Short-term, small-scale interactions between humans and the environment may result in profound transformations of that environment over time. Recent research in Amazonia has revealed the extent that everyday actions, such as the discard of refuse or walking on a path, have modified the geomorphology and soil fertility in the vicinity of ancient settlements. Over time, these activities change the conditions for plants and animals both during and after human occupation of the sites by altering such things as soil moisture and nutrient availability. The fertile anthropic soil known as terra preta, formed mainly through the discard of refuse around habitation areas, is a perfect example of how quotidian actions by humans and other organisms together created these human landscapes. Another example is the numerous incised roadways that have been documented at many sites. These depressions were formed over time by simply walking on a cleared path in tandem with the action of rainwater erosion. Repeated everyday actions have resulted in a widespread pattern where similar features are found in ancient settlements across the broad Amazon region. These landscapes have been documented in several widely spaced areas and in differing contexts, including large sites along major rivers as well as smaller sites in interfluvial areas. The processes of niche construction resulted in patterns of modified soils and geomorphology that reflect the organization and use of space in a settlement. Once these anthropic features are formed, they may serve as landesque capital, spaces that are repeatedly used by succeeding generations or occupations.

Society for American Archaeology, Vancouver, Canada, 2013

Anthrosols known as Amazonian Dark Earth (ADE) or terra preta are part of the ancient human built... more Anthrosols known as Amazonian Dark Earth (ADE) or terra preta are part of the ancient human built landscape representing valuable landscape capital created through chiefly labor control. Their formation is patterned around habitation areas, public areas, and routes of movement, all evidence of a highly organized social structure that is reflected in both landscape and material culture. New data from excavations and topographic mapping, including soil and pottery analyses, from sites in separate regions of Amazonia, demonstrate a widespread pattern of terra preta formation in circular mounds surrounding flat terraces that extends across prehistoric settlements. Results show the interrelationship of residential and public areas, anthrosols, routes of movement, natural resources, and material culture allowing for comment on the relationship between subsistence and social organization in the Amazonian past.

Keywords: Amazonian dark earths, Human built landscape, Terra preta, Labor, Material culture, Amazon archaeology

A Terra Preta de Índio por serem extremamente férteis destacam-se dos solos circunvizinhos pela s... more A Terra Preta de Índio por serem extremamente férteis destacam-se dos solos circunvizinhos pela sua coloração escura, materiais arqueológicos, elevados teores de Ca, Mg, Zn, Mn e P, de carbono orgânico (CO), CTC e SB, proporcionando condições favoráveis ao desenvolvimento das plantas. Foram formadas pela deposição de materiais orgânicos e inorgânicos e normalmente contém grandes quantidades de carvão, o qual acaba contribuindo com a sua alta fertilidade. Esta pesquisa objetivou analisar quimicamente as propriedades de terra preta em um sitio pré-histórico na região do baixo rio Trombetas, a fim de descrever a sua distribuição e quantificação em duas áreas escavadas. Para as análises, os procedimentos de laboratório foram conduzidos segundo os métodos da EMBRAPA (1997). Eles incluem determinação de Al, Ca, Mg disponíveis por KCl 1M; teores de P, K, Na, Cu, Fe, Mn e Zn disponíveis por Mehlich-1; pH em água a 1:2,5; C orgânico por Walkley-Black modificado; e N Total por micro-Kjeldhal. Estas análises foram realizadas com amostras oriundas de pares de escavações provenientes de áreas planas e áreas de montículo associadas a uma e outra. Os nutrientes que mais se destacaram foram o P, Mg, Mn e N junto com o CO elevados principalmente nas áreas de montículo. De acordo com a hipótese, isso ocorre devido os montículos serem áreas de lixeiras onde foi descartado uma maior quantidade de materiais orgânicos, elevando os teores desses nutrientes já existentes no solo.

O artigo avalia a quantificação do teor de carbono orgânico em TPI do sítio PA-OR-127 Cipoal do A... more O artigo avalia a quantificação do teor de carbono orgânico em TPI do sítio PA-OR-127 Cipoal do Araticum, em diferentes escavações. As amostras de solos trabalhadas foram coletadas em níveis de 5 cm, retiradas de duas partes da Escavação, a Esc. 27.1, 27.2 e a Esc. 35 e 36. O processamento das amostras de solo consistiu em organizar, e selecionar as amostras para análise, em seguida foram secas ao ar e tamisadas a 2 mm. A quantificação de Carbono Orgânico foi realizada pelo método de Walkley-Black Modificado. Na escavação 27.1 o teor de carbono orgânico atingiu um máximo de 16,4 g.kg-1 nos primeiros 05 cm e um mínimo de 0,7 g.kg-1 acima dos 50 cm de profundidade. Diferenciando-se da escavação 27.2 em que o teor de carbono foi elevado 32,9 g.kg-1 nos primeiros 05 cm de profundidade, reduzindo a medida que a trincheira se aproximava do solo original, chegando a 4,3 g.kg⁻¹ a partir dos 50 cm de profundidade. Na escavação 35 percebe-se que a quantidade de carbono orgânico foi de 21,2 g.kg-1 nos primeiros 05 cm e de 15,6 g.kg-1 nos últimos centímetros, enquanto que na escavação 36 houve uma variação de 32,6 g.kg-1 a 0,8 g.kg-1. Os teores de carbono orgânico foram mais expressivos nas áreas onde houve uma maior adição de material orgânico de origem animal e vegetal, cinzas e carvão vegetal.

O conhecimento da fertilidade e distribuição de solos antrópicos contribui com interpretações ace... more O conhecimento da fertilidade e distribuição de solos antrópicos contribui com interpretações acerca da classificação espacial, estrutural e funcional de sítios arqueológicos na Amazônia. O presente estudo visa caracterizar valores de pH de solos antrópicos e identificar os seus possíveis padrões de formação, buscando delimitar estrutural e funcionalmente diferentes áreas de atividade humana antepassada. As amostras de solos, coletadas durante escavações arqueológicas em sítios pré-históricos, localizados na região de Porto Trombetas, são provenientes de feições topográficas caracterizadas como montículos de Terra Preta (supostas lixeiras), áreas planas e circulares (supostas áreas domésticas) e de áreas adjacentes aos sítios pré-históricos. Os montículos, em formas curvilíneas, localizados ao redor de áreas planas, apresentam maiores quantidades de vestígios cerâmicos, carvão e solo de coloração escura. As áreas planas apresentam camadas menos espessas de solo escuro com baixas concentrações de material arqueológico. Foram realizadas análises de pH segundo os métodos da Embrapa (1997), demonstrando que os horizontes antropogênicos desenvolveram-se a maiores profundidades nas áreas dos montículos, apresentando pH de baixa acidez em comparação às áreas planas nos sítios estudados e às áreas adjacentes. A maior deposição de materiais orgânicos e inorgânicos nas áreas de montículos em detrimento às áreas planas e adjacentes é o principal fator responsável pelos diferentes valores de pH entre os espaços, demonstrando a conformação estrutural e funcional de atividades antrópicas dos sítios arqueológicos estudados.

Paper presented at the III International Meeting of Amazon Archaeology (EIAA) in Quito, Ecuador, 2013

Resumo expandido apresentado no XXXIV Congresso Brasileiro de Ciência do Solo, Jul 2013

Paper presented at the annual meeting of the Society for American Archaeology in Puerto Rico, 2006

AGU FAll Meeting, 2020

ADE, a result of domestic, economic, and agricultural activities in and around human settlements,... more ADE, a result of domestic, economic, and agricultural activities in and around human settlements, are noted for their extraordinary fertility and resilience and for the significant quantities of organic carbon, much in the form of charcoal. The deepest and most extensive areas of ADE are generally located on the bluffs of major rivers adjacent to floodplains, but significant areas of ADE have also been found in floodplains and in headwater and interfluvial areas. Our research aims to shed light on the distribution of modified soils in distinct regions of the Amazon in relation to landforms and the environment. Although research on ADE has led to a proliferation of studies on charcoal in soil management and the development of a ‘biochar’ industry that promotes the incorporation of charcoal into the soil for the dual purpose of improving fertility and sequestering carbon, there is a notable lack of research attempting to quantify the carbon over the scale of a site or region in Amazonia. We undertook this challenge in the Upper Xingu region of southeastern Amazonia in partnership with the local Kuikuro indigenous community who have shared their valuable traditional knowledge on the creation and management of ADE. We used data from over 3500 soil samples from diverse contexts, both ancient and modern, that we collected and analyzed over the past two decades for organic carbon and a range of other chemical and physical properties. Dark earth samples from profiles down to 1 m depth in archaeological sites ranged from 20% to 150% more OC than unmodified forest soil and dark earth profiles in current and historic villages ranged from 20-90% more. We used the results from soil sample transects to estimate the carbon in landuse zones within and surrounding modern, historic, and ancient settlement sites. In continuing work, we are attempting to use satellite remote sensing and artificial intelligence with ground truth data to extrapolate our results across the Upper Xingu region and beyond.

AGU 100, 2019

Morgan J. Schmidt1, J. Taylor Perron1, Michael Heckenberger2, Wetherbee Dorshow3, Bruno Moraes4, ... more Morgan J. Schmidt1, J. Taylor Perron1, Michael Heckenberger2, Wetherbee Dorshow3, Bruno Moraes4, Jennifer Watling5, Eduardo Neves5, Dorothy Hosler6, Samuel L. Goldberg1, Luiz Fernando Leal7,
Kumessi Waura8, Hulke Kuikuro8, Wate Kuikuro8, Afukaka Kuikuro8

1 Earth, Atmospheric, and Planetary Sciences, MIT; 2 Anthropology, University of Florida; 3 Earth Analytic/ Puente Institute; 4 Emilio Goeldi Museum; 5 Museum of Archaeology and Ethnography, University of Sao Paulo; 6 Materials Science and Engineering, MIT; 7 Florida Institute of Technology; 8 Kuikuro Indigenous Association of the Upper Xingu (AIKAX)

Amazonian dark earth (ADE) has received global attention for its remarkable fertility and high carbon content in a region known for low-nutrient soils. ADE is an anthropic soil produced by human activities, including refuse disposal and crop cultivation, that concentrated charcoal, organic matter and nutrients. Evidence for modified soils reaches back to the terminal Pleistocene in the Amazon while the formation of ADE began by the mid-Holocene and appears to have increased substantially around 3000 years before present. ADE may be a major reservoir of soil carbon, but it is not known how widely distributed it is across the Amazon or how much total carbon it contains. We investigate the extent and composition of ADE in collaboration with the Kuikuro, an indigenous community in the Upper Xingu River Basin, Southeastern Amazon. Recent surveys combining satellite remote sensing with observations from soil pits suggest that modified soils in the Upper Xingu are much more extensive than previously thought. Areas of altered forest visible in satellite images in and around known archaeological sites appear to correlate well with known distributions of darkened and enriched anthropic soils. We test this correlation by quantifying the total carbon and soil fertility across the landscape in the study area. Combining ground truth data from systematic soil sampling with satellite images and machine learning techniques, we create predictive models to estimate the distribution and total carbon content of modified soils in the study area. In the unique context of the Upper Xingu, we explore the formation processes of ADE in a place where it is still being created, while building upon a solid foundation of archaeological research and partnership with the local indigenous community. In ongoing research, we plan to take what we learn from the Upper Xingu and apply it to other regions of the Amazon, using the methods to benefit local communities interested in mapping their cultural landscapes while gaining a better understanding of the magnitude and extent of anthropic soils. Determining the extent to which past human activities modified soils and sequestered carbon in Amazonia offers valuable insights for our efforts to understand human interactions with the environment and how to manage it.

Em sítios arqueológicos na Amazônia as maiores concentrações de cerâmica são frequentemente assoc... more Em sítios arqueológicos na Amazônia as maiores concentrações de cerâmica são frequentemente associadas ao solo modificado, de coloração escura, conhecido como terra preta. Em diferentes regiões da Amazônia, foi identificado um padrão de terra preta em montículos na forma de anel ou arco cercando áreas planas. Há muito tempo, Curt Nimuendajú (1949) observou a superfície ondulada em sítios arqueológicos próximo de Santarém e propôs que as convexidades eram tantos lugares de casas. Apresento resultados de escavações em três regiões que foram realizadas para testar a hipótese de que as áreas planas, ou terraços, eram locais de estruturas, e os montículos ao redor eram áreas de descarte em lixeiras. Nestas lixeiras que se-concentram a cerâmica.

Report of Activities, 2008

Introduction The fieldwork reported on here was carried out at Laguinho archaeological site locat... more Introduction The fieldwork reported on here was carried out at Laguinho archaeological site located on the left bank of the Solimões River (name of the section of Amazon River from the Rio Negro mouth to the border with Colombia and Peru). It is located a short distance up river from the meeting of the waters, where the Rio Solimões and Rio Negro meet, forming a large peninsula of land between the two rivers. This is the study area of the Central Amazon Project, directed by Eduardo Neves from the Museum of Ethnography and Archaeology (MAE) of the University of São Paulo (USP). Laguinho is one of the sites, like Hatahara and Caldeirão, located on the high bluff overlooking the floodplain or várzea (see map). Bluffs in this area rise up to around 60 m above the level of the várzea. Similar anthropic landscape features were documented at the nearby sites Caldeirão and Hatahara, as well as Açutuba located on the opposite site of the peninsula on a beach of the Rio Negro. The information presented here is a result of approximately 15 days of walking over the site and observing the landscape including the topography, soils, vegetation, and water. The main objective was to determine what archaeological landscape features could be detected in the vicinity of the site.

Fieldwork that focused on archaeology of the landscape was carried out during a total of 4 ½ mont... more Fieldwork that focused on archaeology of the landscape was carried out during a total of 4 ½ months between June 2006 and November 2007. Fieldwork was carried out at 3 sites in the study area of the Trombetas project, directed by Vera Guapindaia of the Museu Paraense Emílio Goeldi. The large site of Terra Preta (PA-OR-92) is located on Lake Batata, a permanent floodplain lake beside the lower Trombetas River. The other two sites (Greig I, PA-OR-124 and Greig II, PA-OR-125) are in the area of the plateaus, lying inside the area exploited by the mining company Mineracão Rio do Norte for bauxite (Figure 1).

Film by the Carajás Archaeological Project (PACA). Veja o Filme do Projeto Arqueológico de Caraj... more Film by the Carajás Archaeological Project (PACA).
Veja o Filme do Projeto Arqueológico de Carajás (PACA)

This film with english and portuguese subtitles shows archaeologists in action in Serra do Carajás, in the eastern Amazon, where sites in caves and rock shelters were being used by humans by at least 11,000 years ago. The project is housed at the Emilio Goeldi Museum (MPEG) located at the mouth of the Amazon River in Belem, Para.

Filme mostra as pesquisas arqueológicas sendo realizadas na Serra dos Carajás. O PACA é uma parceria entre o Museu Paraense Emilio Goeldi, a Fundação de Amparo e Desenvolvimento de Pesquisa, e a Vale.

Nature Communications, 2022

Science, 2003

Archaeology and indigenous history of Native Amazonian peoples in the Upper Xingu region of Brazi... more Archaeology and indigenous history of Native Amazonian peoples in the Upper Xingu region of Brazil reveal unexpectedly complex regional settlement patterns and large-scale transformations of local landscapes over the past millennium. Mapping and excavation of archaeological structures document pronounced human-induced alteration of the forest cover, particularly in relation to large, dense late-prehistoric settlements (circa 1200 to 1600 A.D.). The findings contribute to debates on human carrying capacity, population size and settlement patterns, anthropogenic impacts on the environment, and the importance of indigenous knowledge, as well as contributing to the pride of place of the native peoples in this part of the Amazon.

Philosophical Transactions of the Royal Society B: Biological Sciences, 2007

Amazonian Dark Earths: Wim Sombroek's Vision, 2009

Na Amazônia, grande parte dos solos são caracterizados pela baixa concentração de bases trocáveis... more Na Amazônia, grande parte dos solos são caracterizados pela baixa concentração de bases trocáveis e elevada acidez, resultando em baixa fertilidade. No entanto, é possível encontrar manchas de solo escuro, conhecidas como terra preta de índio (TPI) que evidenciam assentamentos que possuem registros arqueológicos. Devido às características inerentes aos solos, como a alta fertilidade dessas regiões, muitos agricultores e pesquisadores tem mostrado interesse no estudo e uso dessas áreas. Estes solos de origem antrópica apresentam altos teores de macro e micronutrientes, pH entre 5,2 e 6,4, além de alto teor de matéria orgânica. Os atributos dos solos de TPI são reflexos de um longo período de depósito de fragmentos de cerâmica e objetos indígenas que foram incorporados a matriz dos horizontes superficiais. O objetivo deste trabalho foi analisar os teores de Ca e acidez dos solos de Terra
Preta no Sítio Arqueológico Usina I localizado no município de Canaã dos Carajás, Pará. Após a coleta das amostras de solo na camada 0-20 cm, foram realizadas as etapas de secagem, peneiramento, catalogação e por fim as análises em laboratório no Centro de pesquisa do Museu Emílio Goeldi, seguindo a metodologia da Embrapa. O teor de Ca foi obtido através de mehlich 1 e o pH em água. Os teores de Ca variaram entre 3,7 e 4,3 cmolc kg⁻¹, considerado médio e adequado para aumentar a produtividade das culturas devido ao maior desempenho no crescimento de raízes, além de reduzir a solubilidade e a toxidez do Mn, Cu e Al, e sua deficiência contribui para a acidificação do solo. O pH variou entre 6,0 e 6,2. O alto teor de matéria orgânica influencia a acidez do solo, visto seu alto poder tampão. O pH da TPI tem grande contribuição na dinâmica de elementos e na biodisponibilidade destes para as plantas. Essas áreas apresentam forte presença de óxido de cálcio, bem como óxidos de P. O Ca na forma de cátion básico contribui fortemente para elevar valores da capacidade de troca de cátions efetiva (CTC) e soma de bases (SB) na TPI. Portanto, a TPI é uma possível solução para a questão da agricultura sustentável em solos pobres e intemperizados.

Alguns sítios arqueológicos são identificados por características de solos de ambientes próximos ... more Alguns sítios arqueológicos são identificados por características de solos de ambientes próximos ou vizinhos, e a alta fertilidade química é um fator determinante aos resultados da habitação humana ao longo do período. Solos antrópicos, modificados pela ação humana, geralmente são determinados por possuírem elevados teores de elementos químicos trocáveis. São características fundamentais de solos antrópicos e com grande quantidade de fragmentos cerâmicos encontrados nos sítios arqueológicos, a coloração escura do solo, normalmente preta, denominando a terra preta arqueológica, devido ao lixo orgânico descartado, que antigamente não era coletado e sim acumulado em um único local, obtendo em um atual contexto a decomposição de matéria orgânica depositada. O objetivo deste trabalho foi determinar através de análises químicas do solo o impacto sofrido por ações antrópicas no sítio Boa Esperança II. As amostras do solo foram coletadas através de uma sondagem e três escavações arqueológicas no sítio Boa Esperança II, localizado em Canaã dos Carajás ao redor do rio Sossego. As análises de macro e micronutrientes foram realizadas nos laboratórios do Museu Paraense Emílio Goeldi e na Embrapa/Belém, conduzidas pelo Método do Manual da Embrapa. Incluiu-se nas análises os resultados de pH, Ca e Mg, P, Cu, Mn, Zn, Sr, Fe e Ba. O pH foi estabelecido entre 6,0 e 7,0, apresentando um solo alcalino. A elevada quantidade de ferro indica um solo perférrico com índices maiores que 360 g.kg de solo, com isso, há a fixação de P, que apresentou baixas concentrações variando de 51,4 a 399 mg.dm 3. A concentração de Ca variou de 705 a 2192 mg.dm 3 e Mg com 232 a 850 mg.dm 3 nos resultados em análise, indicando baixos teores desses macronutrientes no solo. O alto teor de ferro indica possível composição de óxidos de ferro com a presença do mineral hematita, caracterizando a cor avermelhada do solo, além da adsorção dos metais pesados Cu, Mn, Zn, Ba e Sr e fixação do P no solo, afetando a CTC e a boa fertilidade do solo, além da baixa concentração de Ca e Mg que também é explicada por este nutriente.

Ancient anthrosols known as Amazonian dark earths or terra preta are part of the human built land... more Ancient anthrosols known as Amazonian dark earths or terra preta are part of the human built landscape
and often represent valuable landscape capital for modern Amazonian populations in the form of fertile agricultural soils. The fertility, resilience, and large stocks of carbon in terra preta have inspired research on their possible role in soil fertility management and also serve as an example for a growing biochar industry it is claimed will sequester carbon for climate change mitigation. Although there is considerable scientific and public interest in terra preta, there is still much debate and little concrete knowledge of the specific processes and contexts of its formation. Research indicates that the formation of terra preta
occurred mainly in midden deposits, themselves patterned around habitation areas, public areas, and routes of movement. Data from topographic mapping, soil analyses, and excavations in three regions of Amazonia demonstrate a widespread pattern of anthrosol formation in ring-shaped mounds surrounding flat terraces that extend across large areas of prehistoric settlements. It is hypothesized that there is a widespread type or types of occupation where the terraces were domestic areas (houses or yards) surrounded by refuse disposal areas in middens which built up into mounds over time, forming large deposits of terra preta and creating what could be called a ‘middenscape’. Initial results support the hypotheses, showing the interrelationship of residential and public areas, anthrosols, routes of movement, and natural resources. The patterning of anthrosols in ancient settlements indicates the use of
space and can therefore serve as a basis for comparison of community spatial organization between sites and regions

Cada vez mais pesquisas arqueológicas na Amazônia têm revelado ocupações pré-coloniais complexas nas confluências de grandes rios. Em 2014, foram desenvolvidas as primeiras investigações arqueológicas acadêmicas em Gurupá/Pará/Brasil, um município localizado na confluência dos rios Xingu e Amazonas. Entre os séculos XVII e XIX, os Portugueses controlaram o acesso à Amazonia através de uma complexa rede de assentamentos organizada no entorno de Gurupáá. Extensos sítios de Terra Preta, assim como evidências da paisagem e da cerâmica sugerem que este local foi uma importante encruzilhada também no período pré-colonial. Carrazedo, uma importante cidade histórica (Arapijó) está situada sobre um grande sítio de Terra Preta. Escavações nos setores histórico e pré-colonial no sítio evidenciaram vestígios em boas condições de preservação, inclusive um complexo de terraços associados à atividades domésticas. A extensão da terra preta e das áreas que envolvem construções e movimentações de terra sugerem que a ocupação pré-colonial foi mais intensa do que a ocupação colonial/histórica. Levantamentos regionais revelaram que os sítios de habitação históricos e contemporâneos se sobrepõem a extensos sítios pré-coloniais, cuja densidade e tamanho sugerem a existência de importantes centro culturais pré-coloniais na confluência dos rios Xingu e Amazonas. De modo geral, as modificações ecológicas e construções paisagísticas parecem ter sido mais intensas no passado pré-colonial do que nas ocupações históricas subsequentes, e resultados preliminares das análises espaciais e cerâmicas apontam diferenças nas redes de assentamentos locais e regionais relacionadas a estes dois períodos distintos. Assim sendo, esta região pouco estudada se mostra promissora para investigações sobre a história profunda da Amazônia, organização espacial e as interações homem-ambiente nos trópicos húmidos.

PDF completo do livro Amazônia Antropogênica, que versa sobre a antropogênese da seleção humana d... more PDF completo do livro Amazônia Antropogênica, que versa sobre a antropogênese da seleção humana das espécies úteis na Amazônia, da antiguidade dessa seleção, seus mecanismos e consequências teóricas. Tudo isto sob a perspectiva da arqueologia.

submitted to Nature Communications as Matters Arising, 2021

First described over 120 years ago in Brazil, Amazonian Dark Earths (ADEs) are expanses of dark s... more First described over 120 years ago in Brazil, Amazonian Dark Earths (ADEs) are expanses of dark soil that are exceptionally fertile and contain large quantities of archaeological artefacts. The elevated fertility of the dark and often deep A horizon of ADEs is widely regarded as an outcome of pre-Columbian human influence1. Controversially, in their recent paper Silva et al.2argue that the higher fertility of ADEs is principally a result of fluvial deposition and pre-Columbian peoples just made use of these locales rather than contributing to their enhancement. Soil formation is inherently complex and often difficult to interpret, requiring a combination of geochemical data, stratigraphy, and dating. Although Silva et al. use this combination of methods to make their case, their study, based on the analysis of a single ADE site and its immediate surroundings, is too limited to distinguish among the possible mechanisms for ADE formation. Silva et al.’s conclusions contradict decades of research by archaeologists, soil scientists, geographers and anthropologists, who agree that ADEs are anthropic soils formed on land surfaces enriched by inputs resulting from pre-Columbian sedentary settlement. To be accepted, and be pertinent at a regional level, Silva et al.’s hypothesis would need to be supported by extremely solid evidence, which we demonstrate is lacking.

Preprint submitted to Nature Communicationss, 2021

Archaeological research provides clear evidence that the widespread formation of Amazonian Dark E... more Archaeological research provides clear evidence that the widespread formation of Amazonian Dark Earths (ADEs) in tropical lowland South America was concentrated in the Late Holocene, an outcome of sharp demographic growth that peaked towards 1000 BP. In their recent paper, however, Silva et al. propose that the high fertility of ADE is not of anthropic origin but instead the result of alluvial deposition starting in the Middle Holocene (8200-4200 cal BP). In order to support this argument, they marshal data and observations from a single expanse of ADE, the archaeological site of Caldeirão, and disregard or misread other studies of ADEs in the Central Amazon region. Silva et al.'s claim, an epilogue to 'geogenic' models laid to rest over 40 years ago, also dismisses research showing how long-term anthropic soil enrichment occurs as a result of daily practices at contemporary indigenous settlements. Here we critically review Silva et al.'s analysis and affirm that, like most ADEs, Caldeirão has anthropic soil horizons formed by burning, deposition, and reworking of refuse associated with indigenous settlement activities between 2500 and 500 BP.

Encontro Internacional de Arqueologia Amazonica, 2024

Sociedade de Arqueologia Brasileira, 2023

AGU, 2022

Science Podcast, 2023

This podcast is about the intentional creation of dark earth by the Kuikuro indigenous community ... more This podcast is about the intentional creation of dark earth by the Kuikuro indigenous community in the Southern Amazon.

It is the third story in the podcast and begins just after 34 min.