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Cited by 179Amazonian Archaeology and EthnohistorySoil and Environmental StudiesArchaeology and ancient environmental studies

The DOI matches its Crossref record; 72 of the 73 references it cites were found in a registry or an index, and 1 are not checked yet; none of the 103 sources its claims cite is checked for support yet.

Predicting pre-Columbian anthropogenic soils in Amazonia

Open access
McMichael, C. H., Palace, M. W., Bush, M. B., Braswell, B., Hagen, S., Neves, E. G., Silman, M. R., Tamanaha, E. K., Czarnecki, C.·2014·Proceedings of the Royal Society B: Biological Sciences
DOI 10.1098/rspb.2013.2475PMC PMC3896013
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Abstract

The extent and intensity of pre-Columbian impacts on lowland Amazonia have remained uncertain and controversial. Various indicators can be used to gauge the impact of pre-Columbian societies, but the formation of nutrient-enriched terra preta soils has been widely accepted as an indication of long-term settlement and site fidelity. Using known and newly discovered terra preta sites and maximum entropy algorithms (Maxent), we determined the influence of regional environmental conditions on the likelihood that terra pretas would have been formed at any given location in lowland Amazonia.Terra pretas were most frequently found in central and eastern Amazonia along the lower courses of the major Amazonian rivers. Terrain, hydrologic and soil characteristics were more important predictors of terra preta distributions than climatic conditions. Our modelling efforts indicated that terra pretas are likely to be found throughout ca 154 063 km 2 or 3.2% of the forest. We also predict that terra preta formation was limited in most of western Amazonia. Model results suggested that the distribution of terra preta was highly predictable based on environmental parameters. We provided targets for future archaeological surveys under the vast forest canopy and also highlighted how few of the long-term forest inventory sites in Amazonia are able to capture the effects of historical disturbance.

Checked 2026-11-10 · 1 reference not checked yet

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

Using Maxent and 701 known terra preta presence sites, the authors model the environmental likelihood of pre-Columbian anthropogenic soil formation across lowland Amazonia. They estimate terra preta is likely across ca 154,063 km² (3.2% of forest), concentrated in central/eastern Amazonia and riverine settings, with limited western Amazonian occurrence.

Key findings

  • The model had high predictive capacity: mean AUC from 10-fold cross-validation was 0.957 ± 0.006; at a 0.25 probability threshold, 89% of known presence/absence sites were correctly classified, with a 6.5% false negative rate and 4.7% false positive rate.
  • Terrain, geological and hydrological characteristics were more important than climatic ones. Elevation was the most important predictor (permutation importance 61.4945%), constraining terra preta mainly to 0–100 m elevation; geological province was second (5.6174%), with highest likelihood in the Solimões Basin, Ucayali Basin and Brazilian Shield; probability was highest within 10 km of a river and near bluffs greater than 25 m.
  • Terra preta was predicted across ca 154,063 km², or 3.2% of the forest, less than previous estimates of as much as 10%. The model predicted terra preta was limited in most of western Amazonia and almost zero at major archaeological sites in Bolivia, including the Llanos de Moxos and the geoglyph-rich region.

Methods

  • Presence-only Maxent v. 3.3.3 modelling used 701 terra preta presence sites: 201 high-confidence sites from WinklerPrins & Aldrich, 8 from Paz et al., and 463 from E.G.N. and E.K.T. field surveys, across 4,876,193 km² of Amazonian forest.
  • The model included 22 environmental variables (9 climatic, 6 edaphic, 4 topographical, 2 hydrological, 1 geological) resampled to 90 m resolution.
  • Analyses included 10-fold cross-validation, AUC statistics, response curves, permutation importance and jackknife tests; predicted values were then extracted for 2,879 terra preta and terra preta-free sites, and a 0.25 threshold maximizing correct classification was used to estimate the area predicted as terra preta.

Limitations

  • The paper states that because most terra preta and terra preta-free sites lie in Brazil, the most confident predictions are for Brazil; elsewhere predictions are based on larger interpolations and are less certain, and increased sampling will refine estimates outside Brazil.
  • The paper states the model probably overestimates the areas where terra pretas will be found at any given time because it predicts the summed distribution across all ages; terra preta dates are not always contemporaneous, ranging from 3000 to 500 years ago, with most recorded dates from 1000 to 2000 years ago, and continuous occupation after original formation remains unknown.
  • The paper also notes that presence-only modelling was chosen partly because presence sampling was targeted and localized while terra preta-free datasets came from landscape-scale stratified sampling, and RADAM coordinates may be questionable because they predate modern GPS; RADAM and other regional surveys do not contain evidence of terra pretas, but it is not explicit whether they actually searched for them.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1098/rspb.2013.2475

Cites

72 of 73 references verified0 citation errors · 0 not checkable

Statistics

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Verification

Claims the paper makes

0 of 103 cited sources checked · 0 supported · 0 flagged

  • Findingown data
    § 3. Results

    Terrain, geological and hydrological characteristics were more important in shaping terra preta distributions than were climatic ones.

    “Terrain, geological and hydrological characteristics were more important in shaping terra preta distributions than were climatic ones (table 1 and figures 3-5).”
    Quote in the paperSubstantial claim
  • Findingreasoning
    § (a) Soil surveys

    The locations of terra preta-free sites from all of these surveys were combined to form a database of terra preta absences with 1962 sites.

    “The locations of terra preta -free sites from all of these surveys were combined to form a database of terra preta absences ( n ¼ 1962).”
    Quote in the paperSubstantial claim
  • Findingreasoning
    § (a) Soil surveys

    The authors combined 454 sites with 463 georeferenced terra preta sites uncovered by E.G.N. and E.K.T. in archaeological field surveys from 2008 to 2012 to obtain a total of 917 known terra preta locations.

    “We combined these data points with 463 georeferenced terra preta sites uncovered by E.G.N. and E.K.T. in archaeological field surveys from 2008 to 2012 to obtain a total of 917 known terra preta locations (figure 1).”
    Quote in the paperSubstantial claim
  • Findingown data
    § 3. Results

    The probability of finding terra preta is almost zero at the major archaeological sites in Bolivia, including the Llanos de Moxos and the geoglyph-rich region.

    “Model results also indicated that the probability of finding terra preta is almost zero at the major archaeological sites in Bolivia, including the Llanos de Moxos and the geoglyph-rich region (figure 2).”
    Quote in the paperSubstantial claim
  • Findingown data
    § 3. Results

    Terra pretas are most likely to be found in the Solimoes Basin, Ucayali Basin and Brazilian Shield regions.

    “The second most important predictor was geological province, and terra pretas are most likely to be found in the Solimo ˜es Basin, Ucayali Basin and Brazilian Shield regions (figure 3).”
    Quote in the paperSubstantial claim
  • It may state two separate claims as one. 25
  • Probably not a substantial claim. 32

  • It may state two separate claims as one.

    Findingown data
    § 3. Results

    Using the 0.25 threshold, 89% of all cases were predicted correctly, with a false negative rate of 6.5% and a false positive rate of 4.7%.

    “Using the 0.25 threshold, 89% of all cases were predicted correctly, with a false negative rate of 6.5% and a false positive rate of 4.7%.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Findingown data
    § 3. Results

    Terra pretas are most probable within 10 km of a river and near bluffs more than 25 m.

    “Our model suggested that terra preta s are also most probable within 10 km of a river, and near bluffs more than 25 m (figure 3).”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Findingown data
    § 3. Results

    An absence of terra preta was predicted across most of western Amazonia and in the upper catchment areas of southeastern Amazonia.

    “An absence of terra preta was also predicted across most of western Amazonia and in the upper catchment areas of southeastern Amazonia.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Findingown data
    § 3. Results

    The probabilities of finding terra preta for each pixel across Amazonia ranged from 6.2 × 10^-9 to 0.96, with most of Amazonia at the low end of that range.

    “The probabilities ranged from 6.2 -10 2 9 to 0.96, with most of Amazonia at the low end of that range.”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Findingreasoning
    § (a) Spatio-temporal heterogeneity of pre-Columbian peoples

    Terra preta formation was most probable in eastern and central Amazonia and in association with the lower courses of major rivers.

    “Terra preta formation was most probable in eastern and central Amazonia, and in association with the lower courses of major rivers (figures 2 and 6).”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Interpretationown data
    § 3. Results

    The model fitted the data well and had a high predictive capacity.

    “The average AUC value obtained from the 10-fold cross-validation of the model was 0.957, with a standard deviation of + 0.006, which was much higher than that of a random prediction (0.5), and indicated that the model fitted the data well and had a high predictive capacity.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim.

    Premisecitation
    § 1. Introduction

    Whether similar pre-Columbian impacts occur deep within the interior forests and across most of the basin remains unknown.

    “Whether similar impacts occur deep within the interior forests and across most of the basin remains unknown [9,10].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [9] 9. Barlow J, Gardner TA, Lees AC, Parry L, Peres CA. 2012 How pristine are tropical forests? An ecological perspective on the pre-Columbian human footprint in Amazonia and implications for contemporary conservation. Biol. Conserv. 151 , 45-49. (doi:10.1016/j.biocon.2011.10.013) source
    • cites [10] 10. McMichael C, Piperno DR, Bush MB, Silman MR, Zimmerman AR, Raczka MF, Lobato LC. 2012 Sparse pre-Columbian human habitation in western Amazonia. Science 336 , 1429-1431. (doi:10.1126/ science.1219982) source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Study design and conductown data
    § (c) Models and analysis

    The authors evaluated area under the curve (AUC) statistics, which indicated the predictive capacity of a model compared with a random model where AUC equals 0.5.

    “We evaluated area under the curve (AUC) statistics, which indicated the predictive capacity of a model, and how much better (or worse) a given model performed compared with a random model, where AUC ¼ 0.5.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. It may state two separate claims as one.

    Study design and conductown data
    § 1. Introduction

    The model was validated with additional terra preta presence and absence locations and compared with locations of previous ecological and archaeological research in Amazonia.

    “We validated our model with additional terra preta presence and absence locations, and compared the output of our model with locations of previous ecological and archaeological research in Amazonia.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

    Premisenone given
    § 1. Introduction

    Terra pretas are the most widely reported archaeological feature in Amazonia.

    “Terra pretas indicate sedentary pre-Columbian settlements and are the most widely reported archaeological feature in Amazonia.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim.

    Study design and conductcitation
    § (b) Environmental data

    To account for autocorrelation between variables, the authors reduced the 19 bioclimatic variables down to nine using cross-correlation matrices.

    “To account for autocorrelation between variables, we reduced the 19 variables down to nine using cross-correlation matrices [41] (see the electronic supplementary material, figure S1 and table S1).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [41] 41. Buermann W, Saatchi S, Smith TB, Zutta BR, Chaves JA, Mila ´ B, Graham CH. 2008 Predicting species distributions across the Amazonian and Andean - regions using remote sensing data. J. Biogeogr. 35 , 1160-1176. (doi:10.1111/j.1365-2699.2007. 01858.x) source

  • It may state two separate claims as one.

    Study design and conductown data
    § (c) Models and analysis

    The authors modelled terra pretas based solely on presence data because the presence-only dataset was targeted and localized, whereas the terra preta-free datasets were based on landscape-scale stratified sampling designs.

    “We modelled terra pretas based solely on the presence data for several reasons. First, the sampling strategies of the presence-only dataset were targeted and localized, whereas the terra preta -free datasets were based on landscape-scale stratified sampling designs.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Study design and conductreasoning
    § (c) Models and analysis

    RADAM and other regional Brazilian soil surveys do not contain evidence of terra pretas, although it is not explicit whether they actually searched for them.

    “Also, RADAM and other regional Brazilian soil surveys do not contain evidence of terra pretas , although it is not explicit as to whether they actually searched for them.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Interpretationreasoning
    § (a) Spatio-temporal heterogeneity of pre-Columbian peoples

    The distribution of terra pretas may indicate a settlement preference for larger rivers, but may also be related to flood conditions, which are longer but not as deep in the lower courses.

    “This distribution may indicate a settlement preference for larger rivers, but may also be related to flood conditions, which are longer but not as deep in the lower courses.”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Interpretationnone given
    § (a) Spatio-temporal heterogeneity of pre-Columbian peoples

    Terra preta formation increased fertility in soils and afforded repeatable harvests in nutrient-poor areas at higher population densities.

    “The older and highly weathered cratonic soils of eastern Amazonia were particularly nutrientpoor [37,56], and terra preta formation increased fertility in soils and afforded repeatable harvests in nutrient-poor areas at higher population densities.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Study design and conductown data
    § (b) Environmental data

    Because roughness and slope were highly correlated with each other, only roughness metrics were used in the model.

    “Roughness and slope were highly correlated with each other, so only roughness metrics were used in the model (see the electronic supplementary material, figure S1 and table S1).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Premisecitation
    § 1. Introduction

    Pre-Columbian impacts across Amazonia were heterogeneous, both in space and degree.

    “A newly emerging view is that pre-Columbian impacts across Amazonia were heterogeneous, both in space and degree [9,10].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [9] 9. Barlow J, Gardner TA, Lees AC, Parry L, Peres CA. 2012 How pristine are tropical forests? An ecological perspective on the pre-Columbian human footprint in Amazonia and implications for contemporary conservation. Biol. Conserv. 151 , 45-49. (doi:10.1016/j.biocon.2011.10.013) source
    • cites [10] 10. McMichael C, Piperno DR, Bush MB, Silman MR, Zimmerman AR, Raczka MF, Lobato LC. 2012 Sparse pre-Columbian human habitation in western Amazonia. Science 336 , 1429-1431. (doi:10.1126/ science.1219982) source

  • Probably not a substantial claim.

    Premisecitation
    § 1. Introduction

    The overall extent to which lowland Amazonia was actively transformed into a modified landscape or cultural parkland by native people remains unknown and debated.

    “However, the overall extent to which lowland Amazonia was actively transformed into a modified landscape or cultural parkland by native people remains unknown and debated [6-10].”
    Quote in the paperSubstantial claim0 of 5 sources checked
    • cites [6] 6. Erickson CL. 2008 Amazonia: the historical ecology of a domesticated landscape. In The handbook of South American archaeology (eds H Silverman, WH Isbell), pp. 157-183. New York, NY: Springer. source
    • cites [7] 7. Mann CC. 2002 The real dirt on rainforest fertility. Science 297 , 920-923. (doi:10.1126/science.297. 5583.920) source
    • cites [8] 8. Romero S. 2012 Once hidden by forest, carvings in land attest to Amazon's lost world. New York Times . January 15; Sect. A6.
    • cites [9] 9. Barlow J, Gardner TA, Lees AC, Parry L, Peres CA. 2012 How pristine are tropical forests? An ecological perspective on the pre-Columbian human footprint in Amazonia and implications for contemporary conservation. Biol. Conserv. 151 , 45-49. (doi:10.1016/j.biocon.2011.10.013) source
    • cites [10] 10. McMichael C, Piperno DR, Bush MB, Silman MR, Zimmerman AR, Raczka MF, Lobato LC. 2012 Sparse pre-Columbian human habitation in western Amazonia. Science 336 , 1429-1431. (doi:10.1126/ science.1219982) source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation
    § 1. Introduction

    Terra pretas are most commonly found in the central and eastern forests.

    “Terra pretas occur throughout Amazonia, but are most commonly found in the central and eastern forests [26,31], and in riverine settings, particularly along bluffs overlooking the rivers [32].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [26] 26. Sombroek W, Kern D, Rodrigues T, Cravo MS, Jarbas TC, Woods W, Glaser B (eds). 2002 Terra preta and terra mulata : pre-Columbian Amazon kitchen middens and agricultural fields, their sustainability and their replication. In Proc. 17th World Congress of Soil Science , Bangkok, Thailand .

      Checked before — its earlier verdict is held back until a new check runs.

    • cites [31] 31. Glaser B, Birk JJ. 2012 State of the scientific knowledge on properties and genesis of Anthropogenic dark earths in central Amazonia (terra preta de I ´ ndio). Geochim. Cosmochim. Acta 82 , 39-51. (doi:10.1016/j.gca.2010.11.029) source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Study design and conductown data
    § (c) Models and analysis

    The authors performed 10-fold cross-validation of the model, which used all data points for model training and performance testing.

    “We performed 10-fold cross-validation of the model, which was advantageous because all the data points were used for model training and also for performance testing.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation
    § 1. Introduction

    Terra preta soils are anthropogenic soil types usually formed between 500 and 2500 years ago.

    “These anthropogenic soil types were usually formed between 500 and 2500 years ago and contain significantly higher nutrient levels than typical Amazonian soils [4,20,23-28].”
    Quote in the paperNot a substantial claim0 of 8 sources checked
    • cites [4] 4. Neves E, Petersen J. 2006 Political economy and pre-Columbian landscape transformation in central Amazonia. In Time and complexity in historical ecology: studies in the neotropical lowlands (eds W Balee, CL Erickson), pp. 279-310. New York, NY: Columbia University Press. source
    • cites [20] 20. Roosevelt AC. 1991 Moundbuilders of the Amazon: geophysical archaeology on Marajo ´ Island . San Diego, CA: Academic Press.
    • cites [23] 23. Neves E, Petersen J, Bartone R, Augusto Da Silva C. 2004 Historical and socio-cultural origins of Amazonian dark earth. In Amazonian dark earths: origins, properties, management (eds J Lehmann, DC Kern, B Glaser, WI Woods), pp. 29-50. The Netherlands: Kluwer Academic Publisher. source
    • cites [24] 24. Roosevelt AC. 1993 The rise and fall of the Amazon chiefdoms . L'Homme 33 , 255-283. source

      Checked before — its earlier verdict is held back until a new check runs.

    • cites [25] 25. Roosevelt AC et al . 1996 Paleoindian cave dwellers in the Amazon: the peopling of the Americas. Science 272 , 373-384. (doi:10.1126/science. 272.5260.373) source
    • cites [26] 26. Sombroek W, Kern D, Rodrigues T, Cravo MS, Jarbas TC, Woods W, Glaser B (eds). 2002 Terra preta and terra mulata : pre-Columbian Amazon kitchen middens and agricultural fields, their sustainability and their replication. In Proc. 17th World Congress of Soil Science , Bangkok, Thailand .

      Checked before — its earlier verdict is held back until a new check runs.

    • cites [27] 27. Sombroek WG. 1966 Amazon soils: a reconnaissance of the soils of the Brazilian Amazon region . Wageningen, The Netherlands: Centre for Agricultural Publications and Documentation. source

      Checked before — its earlier verdict is held back until a new check runs.

    • cites [28] 28. Woods WI, McCann JM. 1999 The anthropogenic origin and persistence of Amazonian dark earths. Yearb. Conf. Latin Am. Geogr. 25 , 7-14.

  • It may state two separate claims as one.

    Premisecitation
    § (a) Spatio-temporal heterogeneity of pre-Columbian peoples

    The eastern sections of the Amazon River are less turbid and have slower flow and meander rates compared with the western sections.

    “Furthermore, the eastern sections of the Amazon River are less turbid and have slower flow and meander rates compared with the western sections [60].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [60] 60. Mertes LAK, Dunne T, Martinelli LA. 1996 Channelfloodplain geomorphology along the SolimoesAmazon River, Brazil. GSA Bull. 108 , 1089-1107. (doi:10.1130/0016-7606(1996)108 , 1089: CFGATS . 2.3.CO;2)

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation
    § 1. Introduction

    Terra pretas are most commonly found in riverine settings, particularly along bluffs overlooking the rivers.

    “Terra pretas occur throughout Amazonia, but are most commonly found in the central and eastern forests [26,31], and in riverine settings, particularly along bluffs overlooking the rivers [32].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [32] 32. Denevan WM. 1996 A bluff model of riverine settlement in prehistoric Amazonia. Ann. Assoc. Am. Geogr. 86 , 654-681. (doi:10.1111/j.1467-8306. 1996.tb01771.x) source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Study design and conductreasoning
    § (c) Models and analysis

    The threshold method allowed estimation of false positive and false negative rates of the model.

    “This method allowed us to estimate false positive and false negative rates of the model.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper may give no reason why it holds.

    Interpretationnone given
    § 1. Introduction

    The noted patterns of terra preta distribution may result from increased sampling effort in these locations.

    “However, the noted patterns may result from increased sampling effort in these locations.”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Premisecitation
    § (a) Soil surveys

    Cooper et al. published a comprehensive database of soil surveys conducted in Brazil, with most data points originating from the RADAMBrasil Project.

    “Cooper et al . [34] published a comprehensive database of soil surveys conducted in Brazil, with most data points originating from the field campaign of the RADAMBrasil Project (Radar in Amazonia) [33].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [34] 34. Cooper M, Mendes LMS, Silva WLC, Sparovek G. 2005 A national soil profile database for Brazil available to international scientists. Soil Sci. Soc. Am. J. 69 , 649-652. (doi:10.2136/sssaj2004.0140) source
    • cites [33] 33. Brazil MdMeE, Departamento Nacional de Produca ˜o Mineral (DNPM). 1973-1983 Projeto RADAMBRASIL: 1973-1983, Levantamento de Recursos Naturais. DNPM, Rio de Janeiro.

  • Probably not a substantial claim.

    Study design and conductcitation
    § (c) Models and analysis

    A probability threshold value for predicting terra preta presence and absence was generated based on maximizing the percentage of sites correctly classified.

    “A probability threshold value for predicting terra preta presence and absence was generated based on maximizing the percentage of sites correctly classified [51].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [51] 51. Freeman EA, Moisen G. 2008 PRESENCEABSENCE: an R package for presence absence analysis. Statist. Softw. 23 , 1-31. source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation
    § 1. Introduction

    Terra preta formation has been estimated to occur in as much as 10% of the forests.

    “Terra preta formation has been estimated to occur in as much as 10% of the forests [6,7], but a prediction derived from empirical data and modelling is lacking.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [6] 6. Erickson CL. 2008 Amazonia: the historical ecology of a domesticated landscape. In The handbook of South American archaeology (eds H Silverman, WH Isbell), pp. 157-183. New York, NY: Springer. source
    • cites [7] 7. Mann CC. 2002 The real dirt on rainforest fertility. Science 297 , 920-923. (doi:10.1126/science.297. 5583.920) source

  • It may state two separate claims as one.

    Interpretationreasoning
    § (a) Spatio-temporal heterogeneity of pre-Columbian peoples

    The stability of eastern Amazonian river sections may have favoured larger and more permanent settlements in eastern Amazonia, particularly in regions such as Santarem, where some of the oldest records of human occupation in Amazonia have been identified.

    “This stability may have also favoured larger and more permanent settlements in eastern Amazonia, particularly in regions such as Santarem, where some of the oldest records of human occupation in Amazonia have been identified [21,25].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [21] 21. Roosevelt AC, Housley RA, Imazio da Siveira M, Maranca S, Johnson R. 1991 Eighth millenium pottery from a prehistoric shell midden in the Brazilian Amazon. Science 254 , 1621-1624. (doi:10.1126/science.254.5038.1621) source
    • cites [25] 25. Roosevelt AC et al . 1996 Paleoindian cave dwellers in the Amazon: the peopling of the Americas. Science 272 , 373-384. (doi:10.1126/science. 272.5260.373) source

  • Probably not a substantial claim. It may be too vague to check against evidence. The paper may give no reason why it holds.

    Interpretationreasoning
    § (b) Archaeological and ecological implications

    Our model provides a basis for linking historical trajectories of forest change with forest inventory data and ecological surveys conducted in Amazonia over modern timescales.

    “Our model provides a basis for linking historical trajectories of forest change with forest inventory data and ecological surveys conducted in Amazonia over modern timescales.”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Premisecitation
    § (a) Spatio-temporal heterogeneity of pre-Columbian peoples

    Dates from terra pretas are not always contemporaneous, and range from 3000 to 500 years ago.

    “Dates from terra pretas are not always contemporaneous, and range from 3000 to 500 years ago.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [22] 22. Neves EG, Petersen JB, Bartone RN, Heckenberger MJ. 2004 The timing of terra preta formation in the Central Amazon: archaeological data from three sites. In Amazonian dark earths: explorations in space and time (eds B Glaser, WI Woods), pp. 125-134. Berlin, Germany: Springer. source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation
    § (a) Spatio-temporal heterogeneity of pre-Columbian peoples

    The geoglyph-rich region at least partially overlaps with expansive bamboo-dominated forests in Amazonia that have persisted in the landscape for thousands of years.

    “Interestingly, the geoglyph-rich region at least partially overlaps with expansive bamboo-dominated forests in Amazonia (figure 2) [62] that have persisted in the landscape for thousands of years [36].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [62] 62. de Carvalho AL, Nelson BW, Bianchini MC, Plagnol D, Kuplich TM, Daly DC. 2013 Bamboo-dominated forests of the southwest Amazon: detection, spatial extent, life cycle length and flowering waves. PLoS ONE 8 , e54852. (doi:10.1371/journal.pone.0054852) source
    • cites [36] 36. McMichael CH, Bush MB, Silman MR, Piperno DR, Raczka M, Lobato LC, Zimmerman M, Hagen S, Palace M. 2012 Historical fire and bamboo dynamics in western Amazonia. J. Biogeogr . 40 , 299-309. (doi:10.1111/jbi.12002) source

  • It may state two separate claims as one.

    Premisecitation
    § (a) Spatio-temporal heterogeneity of pre-Columbian peoples

    In much of western Amazonia, human activity was heterogeneous, localized and low-impact, with people sparsely scattered and practicing small-scale clearing and cultivation, except in earthwork-rich areas of southwestern Amazonia.

    “although multiple lines of palaeoecological evidence suggest heterogeneous and localized low-impact human activity in much of western Amazonia [10].”
    • Also stated in: § (a) Spatio-temporal heterogeneity of pre-Columbian peoples · hedged
      “That is not to say people were absent from western Amazonia; most evidence indicates that with the exception of the earthwork-rich areas in southwestern Amazonia, people were sparsely scattered through the landscape, clearing small tracts of land and growing crops on localized scales.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [10] 10. McMichael C, Piperno DR, Bush MB, Silman MR, Zimmerman AR, Raczka MF, Lobato LC. 2012 Sparse pre-Columbian human habitation in western Amazonia. Science 336 , 1429-1431. (doi:10.1126/ science.1219982) source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation
    § (b) Archaeological and ecological implications

    Terra pretas are often identified by locals as secondary forests with a predictable suite of species, many of which are domesticated.

    “Previous field reports have documented that terra pretas are often associated with lower canopy height [28], denser understory [28], increased frequencies of lianas [67] and are often identified by locals as secondary forests with a predictable suite of species, many of which are domesticated (e.g. [68,69]).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [68] 68. Clement C, McCann J, Smith N. 2004 Agrobiodiversity in Amazonia and its relationship with dark earths. In Amazonian dark earths (eds B Glaser, WI Woods), pp. 159-178. Berlin, Germany: Springer. source
    • cites [69] 69. Junqueira AB, Shepard GH, Clement CR. 2011 Secondary forests on anthropogenic soils of the middle Madeira river: valuation, local knowledge, and landscape domestication in Brazilian Amazonia. Econ. Bot. 65 , 1-15. (doi:10.1007/s12231-0109138-8) source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation
    § (a) Spatio-temporal heterogeneity of pre-Columbian peoples

    At least some aspects of the accounts of the Amazon river are of dubious reliability, specifically the description of a nation of warrior women (the Amazons).

    “although at least some aspects of these accounts are of dubious reliability, i.e. the description of a nation of warrior women-the Amazons [61].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [61] 61. Medina J. 1934 The discovery of the Amazon according to the account of Friar Caspar de Carvajal and other documents . New York, NY: American Geographical Society.

  • It may state two separate claims as one.

    Interpretationcitation
    § (b) Archaeological and ecological implications

    Other 'anthropogenic' forests that were formed in pre-Columbian periods may be identifiable within the forest today, as some species, including some palms, were heavily promoted species.

    “Other 'anthropogenic' forests that were formed in pre-Columbian periods may be identifiable within the forest today, as some species, including some palms, were heavily promoted species [6,70-72].”
    Quote in the paperNot a substantial claim0 of 4 sources checked
    • cites [6] 6. Erickson CL. 2008 Amazonia: the historical ecology of a domesticated landscape. In The handbook of South American archaeology (eds H Silverman, WH Isbell), pp. 157-183. New York, NY: Springer. source
    • cites [70] 70. Balee W. 1989 The culture of Amazonian forests. In Resource management in Amazonia: indigenous and folk strategies (eds DA Posey, W Balee), pp. 1-21. New York, NY: New York Botanical Garden.
    • cites [71] 71. Balee W. 2010 Contingent diversity on anthropic landscapes. Diversity 2 , 163-181. (doi:10.3390/ d2020163) source
    • cites [72] 72. Levis C, de Souza PF, Schietti J, Emilio T, da Veiga Pinto JLP, Clement CR, Costa FRC, Hart JP. 2012 Historical human footprint on modern tree species composition in the Purus-Madeira Interfluve, central Amazonia. PLoS ONE 7 , e48559. (doi:10.1371/ journal.pone.0048559) source

      Checked before — its earlier verdict is held back until a new check runs.

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

    Interpretationnone given
    § (a) Spatio-temporal heterogeneity of pre-Columbian peoples

    Some terra preta sites, particularly the smaller ones, may have been used only briefly.

    “Some sites, particularly the smaller ones, may have been used only briefly.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation
    § (b) Archaeological and ecological implications

    Terra pretas are often associated with denser understory.

    “Previous field reports have documented that terra pretas are often associated with lower canopy height [28], denser understory [28], increased frequencies of lianas [67] and are often identified by locals as secondary forests with a predictable suite of species, many of which are domesticated (e.g. [68,69]).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [28] 28. Woods WI, McCann JM. 1999 The anthropogenic origin and persistence of Amazonian dark earths. Yearb. Conf. Latin Am. Geogr. 25 , 7-14.

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Premisecitation
    § (a) Spatio-temporal heterogeneity of pre-Columbian peoples

    Carvajal's account describes the western river sections as desolate, with the expedition starving to the point of eating shoe leather.

    “Also, Carvajal's account describes the western river sections as desolate, with the expedition starving to the point of eating shoe leather [61].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [61] 61. Medina J. 1934 The discovery of the Amazon according to the account of Friar Caspar de Carvajal and other documents . New York, NY: American Geographical Society.

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Interpretationcitation
    § (a) Spatio-temporal heterogeneity of pre-Columbian peoples

    The lack of terra pretas in western Amazonia may be because the Andean-derived soils of western Amazonia did not require nutrient enrichment, or because the human footprint in western Amazonia is for the most part smaller than that in the east.

    “The lack of terra pretas in western Amazonia may be because the Andean-derived soils of western Amazonia did not require nutrient enrichment, or because the human footprint in western Amazonia is for the most part smaller than that in the east.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Interpretationreasoning
    § (a) Spatio-temporal heterogeneity of pre-Columbian peoples

    The geoglyph builders may have been more culturally similar to people of the Beni.

    “Thus, the geoglyph builders may have been more culturally similar to people of the Beni.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation
    § (b) Archaeological and ecological implications

    Terra pretas are often associated with increased frequencies of lianas.

    “Previous field reports have documented that terra pretas are often associated with lower canopy height [28], denser understory [28], increased frequencies of lianas [67] and are often identified by locals as secondary forests with a predictable suite of species, many of which are domesticated (e.g. [68,69]).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [67] 67. Balee W, Campbell DG. 1990 Evidence for the successional status of liana forest (Xingu river basin, Amazonian Brazil). Biotropica 22 , 36-47. (doi:10. 2307/2388717) source

  • Probably not a substantial claim.

    Interpretationreasoning
    § (b) Archaeological and ecological implications

    These ecological data lack a historical perspective.

    “Although these data have been immensely valuable in deciphering many of the underlying mechanisms that shape forest composition, structure and change, they lack a historical perspective.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim.

    Premisecitation
    § (b) Archaeological and ecological implications

    Many tree species in Amazonia live several hundred years.

    “Many tree species in Amazonia live several hundred years [66]”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [66] 66. Hartshorn G, Zimmerman M. 1978 Tree falls and tropical forest dynamics. In Tropical trees as living systems (eds PB Tomlinson, MH Zimmerman), pp. 617-638. Cambridge, UK: Cambridge University Press.

  • Probably not a substantial claim.

    Premisecitation
    § (b) Archaeological and ecological implications

    Historical contingency, or historical trajectory, can play just as large a role in shaping observed ecological phenomena as modern climatic and abiotic conditions.

    “It has been suggested that the historical contingency, or historical trajectory, can play just as large a role in shaping observed ecological phenomena as modern climatic and abiotic conditions [64,65].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [64] 64. Ricklefs RE, Latham RE, Qian H. 1999 Global patterns of tree species richness in moist forests: distinguishing ecological influences and historical contingency. OIKOS 86 , 369-373. (doi:10.2307/ 3546454) source
    • cites [65] 65. Ricklefs RE, Schluter D. 1993 Species diversity in ecological communities: historical and geographical perspectives . Chicago, IL: University of Chicago Press.

  • It may state two separate claims as one.

    Interpretationnone given
    § (b) Archaeological and ecological implications

    Our model predicts where ancient impacts should be the most intense, even under the forest canopy, and provides basin-wide target locations for archaeologists who study ancient societies within Amazonian rainforests.

    “Our model predicts where ancient impacts should be the most intense, even under the forest canopy, and provides basin-wide target locations for archaeologists who study the rich culture of ancient societies within the vast Amazonian rainforests (figure 6).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation
    § (b) Archaeological and ecological implications

    Terra pretas are often associated with lower canopy height.

    “Previous field reports have documented that terra pretas are often associated with lower canopy height [28], denser understory [28], increased frequencies of lianas [67] and are often identified by locals as secondary forests with a predictable suite of species, many of which are domesticated (e.g. [68,69]).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [28] 28. Woods WI, McCann JM. 1999 The anthropogenic origin and persistence of Amazonian dark earths. Yearb. Conf. Latin Am. Geogr. 25 , 7-14.

  • It may state two separate claims as one.

    Study design and conductreasoning
    § (b) Archaeological and ecological implications

    Elsewhere in Amazonia, the predictions are based on larger interpolations and are less certain.

    “Elsewhere in Amazonia, the predictions are based on larger interpolations and are less certain.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Premisecitation
    § (b) Archaeological and ecological implications

    Many archaeological sites are discovered accidentally through deforestation or as a result of conversations with local people.

    “Many archaeological sites are discovered accidentally through deforestation [3,15] or as a result of conversations with local people.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [3] 3. Pa ¨rssinen M, Schaan D, Ranzi A. 2009 PreColumbian geometric earthworks in the upper Puru ´s: a complex society in western Amazonia. Antiquity 83 , 1084-1095.
    • cites [15] 15. Ranzi A, Feres R, Brown F. 2007 Internet software programs aid in search for Amazonian geoglyphs. EOS Trans. 88 , 226-229. (doi:10.1029/ 2007EO210003) source

  • Probably not a substantial claim.

    Interpretationreasoning
    § (b) Archaeological and ecological implications

    The long-term study sites near Manaus and Santarem are particularly promising for local-scale evaluations of pre-Columbian disturbance on forest structure.

    “Most of the previous forest inventory research occurred in areas that most probably do not contain terra pretas , but the long-term study sites near Manaus and Santarem are particularly promising for local-scale evaluations of pre-Columbian disturbance on forest structure (sites C and S in figure 6).”
    Quote in the paperSubstantial claim
50 of 50

  • The paper relies on this without support.

    The potential for terra preta formation exists throughout Amazonia.

    “As the potential for terra preta formation exists throughout Amazonia, we hypothesized that regional environmental conditions and local sociocultural practices influenced how people lived and that, in turn, affected their likelihood of creating terra preta .”

  • The paper relies on this without support.

    Modern environmental conditions used as predictors are relevant to the likelihood of pre-Columbian terra preta formation across Amazonia.

    “we modelled the potential distribution of terra pretas based on presence locations and a suite of climatic, geological, terrain and hydrological conditions across Amazonia.”

  • The paper relies on this without support.

    A prediction of terra preta formation derived from empirical data and modelling is lacking.

    “Terra preta formation has been estimated to occur in as much as 10% of the forests [6,7], but a prediction derived from empirical data and modelling is lacking.”

  • The paper relies on this without support.

    None of the predicted highly impacted areas are as biodiverse as the forests of northwestern Amazonia, which contain the highest tree-species diversity per unit area.

    “None of the predicted highly impacted areas are as biodiverse as the forests of northwestern Amazonia, which contain the highest tree-species diversity per unit area.”

  • The paper relies on this without support.

    Most ecological data collection and field surveys, particularly in the Neotropics, have been conducted over recent timescales, i.e. the past 50 years.

    “Most ecological data collection and field surveys, particularly in the Neotropics, have been conducted over recent timescales, i.e. the past 50 years.”

  • The paper relies on this without support.

    The Llanos de Moxos region of Bolivia is located in seasonally inundated forests at the forest-savannah transition.

    “The Llanos de Moxos regions of Bolivia is located in seasonally inundated forests at the forest-savannah transition, and instead of terra preta formation, large societies sustained themselves by using techniques such as fish weirs and raised-field agriculture (e.g. [12]).”
6 of 6

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • The idea of rivers as corridors for easy transportation and communication has been suggested in Amazonia and shown to be significant in predicting anthropogenic soils.

    “The idea of rivers as corridors for easy transportation and communication has been suggested in Amazonia [72] and shown to be significant in predicting anthropogenic soils [43].”

    From Potential distributions of pre-columbian people in tropical andean landscapes (2022) · cites this paper as [43]

  • The SDM approach has also been used to predict the distributions of past people across landscapes.

    “and the approach has also been used to predict the distributions of past people across landscapes [16,43,44].”

    From Potential distributions of pre-columbian people in tropical andean landscapes (2022) · cites this paper as [43]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

  • Model-site counts total 672, not 701

    Minor

    The three stated groups of sites sum to 672, rather than the reported total of 701.

    Reported 701 · recomputed 672

  • Environmental-layer categories total 46, not 45

    Minor

    The listed categories contain 19 + 16 + 8 + 2 + 1 = 46 layers, one more than the stated total of 45.

    Reported 45 · recomputed 46

2 of 2

Citations

Cites

Flagged first, then by citations

Research works printed but not linked: 5

  1. Roosevelt AC, 1991, Moundbuilders of the Amazon: geophysical archaeology on Marajó Island
  2. Sombroek W, 2002, Proc. 17th World Congress of Soil Science
  3. Bow J, 2008, Terrestrial ecosystems of South America
  4. Freeman EA, 2008, Statist. Softw., 23, 1
  5. RStudio, 2012, RStudio: integrated development environment for R (version 0.96.331)

Cited by

Sorted by citations

Related

Metadata

Authors
McMichael, C. H., Palace, M. W., Bush, M. B., Braswell, B., Hagen, S., Neves, E. G., Silman, M. R., Tamanaha, E. K., & Czarnecki, C.
Affiliations
  • Earth Systems Research Center, University of New Hampshire, Durham, NH 03824, USA
  • Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL 32901, USA
  • Applied Geosolutions, Durham, NH 03824, USA
  • Laboratório de Arqueologia dos Trópicos, Museu de Arqueologia e Etnologia, Universidade de São Paulo, São Paulo, Brazil
  • Department of Biology and Center for Energy, Environment and Sustainability, Wake Forest University, Winston-Salem, NC 27106, USA
  • Florida Institute of Technology (US)
Venue
Proceedings of the Royal Society B: Biological Sciences
Publisher
The Royal Society
Published
2014-02-22
Volume
281
Issue
1777
Pages
20132475
ISSN
  • 0080-4649 (ISSN-L)
  • 0962-8452
  • 1471-2954
DOI
10.1098/rspb.2013.2475
PMC
PMC3896013
OpenAlex
W2111058040
Cited by
179
References
70
Citations by year
2026: 7 · 2025: 7 · 2024: 5 · 2023: 16 · 2022: 10 · 2021: 17 · 2020: 26 · 2019: 15 · 2018: 20 · 2017: 15 · 2016: 19 · 2015: 19 · 2014: 3
FWCI
353.22
Type
journal article
Language
en
Open access
Licence
royalsociety.org/journals/ethics-policies/data-sharing-mining/ (tdm)
Locations
  • Proceedings of the Royal Society B Biological Sciences (publishedVersion)
  • Europe PMC (PubMed Central) (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • University of New Hampshire Scholars Repository (University of New Hampshire at Manchester) (submittedVersion)
Topics
  • Social Sciences › Arts and Humanities › History › Amazonian Archaeology and Ethnohistory
  • Life Sciences › Agricultural and Biological Sciences › Soil Science › Soil and Environmental Studies
  • Social Sciences › Archeology › Archaeology and ancient environmental studies
Keywords
terra preta, pre-Columbian societies, anthropogenic soils, Amazon basin, maximum entropy, environmental predictors, site fidelity, Amazonian rivers
MeSH terms
Algorithms, Archaeology, Environment, Soil, South America

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

A language model drew the claims from the paper on 2026-11-10, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).

A second model labelled each claim on 2026-11-10 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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