Anthrosols and human carrying capacity in amazonia
Anthrosols and Human Carrying Capacity in AmazoniaAuthor(s): Nigel J. H. SmithSource: Annals of the Association of American Geographers, Vol. 70, No. 4 (Dec., 1980), pp.553-566Published by: Taylor & Francis, Ltd. on behalf of the Association of American GeographersStable URL: http://www.jstor.org/stable/2562927 .Accessed: 13/06/2011 18:43Your use of the JSTOR archive indicates your acceptance of JSTORs Terms and Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp. JSTORs Terms and Conditions of Use provides, in part, that unlessyou have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and youmay use content in the JSTOR archive only for your personal, non-commercial use.Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at .http://www.jstor.org/action/showPublisher?publisherCode=taylorfrancis. .Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printedpage of such transmission.JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range ofcontent in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact email@example.com.Taylor & Francis, Ltd. and Association of American Geographers are collaborating with JSTOR to digitize,preserve and extend access to Annals of the Association of American Geographers.http://www.jstor.org
ANTHROSOLS AND HUMAN CARRYINGCAPACITY IN AMAZONIA*NIGEL J. H. SMITHABSTRACT. The occurrence of numerous areas of black soil associated withpotsherds in Amazonia has stirred controversy on the origins of the soil type andits significance in terms of precontact aboriginal population densities in the region.The theories on the origin of black earth are reviewed and it is argued that it isanthropogenic. An analysis of the physical and chemical properties of the soiltype, based on widespread sampling, supports the anthropogenic argument. Theabundance and depth of black earth sites indicates that Indian populations weredense and in many cases sedentary before the arrival of Europeans, even ininterfluve areas.THE current low population density ofAmazonia, with only I inhabitant per sq.km, has long puzzled geographers, anthropol-ogists, sociologists, and economists. Whydoes such a huge area, roughly 7 million sq.km, which contains one of the worlds richestbiomes, contain so few people? According toone viewpoint, the rain forest is not conduciveto the development of higher cultures.1 Themeager protein sources and the generally poorsoils of the uplands (terra firme), it is argued,mitigate against sedentary settlement by abo-rigines. Even in floodplain areas, the pervad-ing influence of the rain forest supposedly ar-rests cultural development.Dr. Smith is Senior Researcher at Worldwatch Insti-tute, 1776 Massachusetts Ave., N.W., Washington, DC20036.* Soil samples were collected under grants from theCenter for Latin American Studies, Berkeley, a DeansFellowship, University of California, Berkeley, and fromINPA, Manaus. I am grateful to Italo Falesi for arrangingto have the soil samples analyzed at the EMBRAPA andIDESP laboratories in Bel6m, Brazil. I would like to thankthe Ford Foundation for providing me with a travel grantto conduct library research for the paper at Berkeley. Iam also grateful to David Arkcoll, Woodrow Borah, Su-sanna Hecht, and an anonymous reviewer for their helpfulcomments on a preliminary version of the manuscript.1 B. Meggers, "Environmental Limitation and the De-velopment of Culture," American Anthropologist, Vol.56 (1954), pp. 801-24; E. Ferdon, "Agricultural Potentialand the Development of Cultures," Southwestern Journalof Anthropology, Vol. 15 (1959), pp. 1-19; and B. Meg-gers, Amazonia: Man and Culture in a Counterfeit Par-adise (Chicago: Aldine-Atherton, 1971).This paper proposes that the human carry-ing capacity of Amazonia is greater than hasbeen generally accepted. A mosaic of blackearth patches, scattered throughout the Am-azon basin, provides evidence that precontactnative populations were in many cases largeand sedentary. Black earth, ceramic material,and stone tools are the only vestiges of ancientcivilizations in Amazonia; the remainder, ex-cept for artificial mounds, has perished underthe hot and humid conditions. To examine thecase for the anthropogenic origin of blackearth, theories on its genesis are examined,the physical and chemical properties of thesoil type are analyzed, and the site character-istics are described. Finally, the controversyon the scarcity of subsistence resources in theregion is explored.THEORIES ON THE ORIGIN OFBLACK EARTHIn the Brazilian Amazon, black earth withpotsherds is referred to as terra preta do indio(Indian black earth) and is recognized as a soiltype.2 Terra preta is an anthrosol, character-ized by a distinctive anthropogenic epipedon.3Intermixed potsherds and celts are a majordistinguishing feature of the soil. Dark soilsrarely occur without the influence of man in2 I. Falesi, "Soils of the Brazilian Amazon," in C. Wag-ley, ed., Man in the Amazon (Gainesville: University ofFlorida Press, 1974), pp. 201-29.3J. Bennema, "Soils," in P. Alvim and T. Kozlowski,eds., Ecophysiology of Tropical Crops (New York: Ac-ademic Press, 1977), pp. 29-55.ANNALS OF THE ASSOCIATION OF AMERICAN GEOGRAPHERS Vol. 70, No. 4, December 1980? 1980 by the Association of American Geographers. Printed in U.S.A.553
554 NIGEL J. H. SMITH DecemberAmazonia; alluvial soils rich in organic matterare an exception. But Indian black earth isfound on a variety of soil types and geomor-phological surfaces, and retains its sooty coloreven under intense leaching.Fallout from volcanoes in the Andes hasbeen suggested as the origin of black earth lo-calities on the Belterra plateau south of San-tarem.4 Black earth sites supposedly are onlyfound on the highest portions of the plateauthat would have trapped ash in a manner sim-ilar to snowdrifts. The decrease in the levelsof phosphorus and calcium down the blackearth profiles is cited as further evidence thatthey are due to volcanic precipitation in thelate Tertiary or early Quaternary. Aboriginessubsequently occupied the sites leaving bro-ken pieces of pottery and stone tools as ves-tiges.Several problems arise with the volcanicash theory. First, prevailing winds in Ama-zonia blow from east to west, thus renderingunlikely the aerial transport of debris severalthousand km from the west. Even if the pre-vailing winds were reversed in the past, onewould expect a reasonably even distributionof ash over large areas, similar to loess soils,rather than in irregular patches. Second, thetheory does not explain why potsherds are en-countered throughout the profile since plough-ing in Amazonia is extremely rare and wasalmost certainly absent in precontact times.Some tribes practice secondary burial in urns,but that would not account for the wide vari-ety of pottery and celts found in black earthprofiles. Third, it is normal for calcium andphosphorus salts to diminish down the profilein most soils since the litter decomposes, andnutrients are generally recycled, close to thesurface.Sedimentation in lakes has been proposedas another origin of terra preta do indio.5 Ac-cording to this theory, black earth patchesformed when a large Tertiary lake, formed bythe rising Andes, eventually broke through thegranitic shield in the east and flowed, as theAmazon River, to the Atlantic. As the vastlake drained, ponds appeared on the unevenbed and these depressions slowly filled in withplants and animals. The incorporation of ani-4F. Camargo, "Estudo de Alguns Perfis de Solo Col-etados em Diversas Regi6es da Hilia," mimeo (no date),59 pp., in Embrapa library, Belem, Brazil.5Falesi, op. cit., footnote 2.matbones in the eutrophication process wouldaccount for the generally high phosphoruscontent of black earth.It is not certain, however, that a lakeformed when the Andes emerged at the begin-ning of the Tertiary.6 Tertiary sediments, ex-tending down several thousand meters insome areas, may have resulted from alluvialor colluvial fill.7 Another problem with thetheory is that terra preta sites are also foundin areas that would not have been covered bythe lake in the western half of Amazonia, suchas the Pre-Cambrian Brazilian shield and Si-lurian diabase dikes. Furthermore, Indianblack earth is found on Quaternary alluvium.Another version of the pond theory con-tends that the terra preta sites on the Belterraplateau were formed in recent times. Smalldepressions would fill with water in the rainyseason and erosion of litter from surroundingvegetation, as well as organic matter fromaquatic plants, would eventually fill in theponds and produce a rich, dark soil. Mean-while, Indians would use the ponds to softenmanioc tubers before making flour. Discardedplatters, once used on the ovens to toast theflour, would account for sherds in the soil.8A major problem with the recent pond the-ory is that black earth sites also occur in areaswhere water is unlikely to collect, such as onhigh banks overlooking rivers, or on tops ofhills. Furthermore, it seems unlikely that ab-origines would toss garbage and broken pot-tery into ponds, thereby polluting their watersupply.The impressive number of terra preta sitesalong the Trombetas and Jamundacrivers hasled one author to speculate that they musthave resulted from the filling in of floodplainlakes.9 This theory does not explain how blackearth sites are formed on terra firme.6 The geomorphological history of Amazonia is poorlyunderstood. See, for example, N. AbSaber, "ProblemasGeomorfol6gos da Amaz6nia Brasileira," Atas do Sim-p6sio s6bre a Biota Amnaz6nica,Vol. 1 (1967), pp. 35-67;and H. Sternberg, "The Amazon River of Brazil," Erd-kundliches Wissen, Vol. 40 (1975), pp. 1-74.7 J. Mabessone, "Sedimentos Correlativos do ClimaTropical," Atas do Simp6sio s6bre a Biota Amaz6nica,Vol. 1 (1967), pp. 327-37."E. Cunha Franco, "As Terras Pretas do Planalto deSantar6m," Revista da Sociedade dos Agronomos e Ve-terinariosdo Parid, Vol. 8 (1962), pp. 17-21.9J. Faria, A Ceramica da Tribo Uaboi dos Rios Trom-betas e Jamundd (Rio de Janeiro: Imprensa Nacional,1946).
1980 ANTHROSOLS AND CARRYING CAPACITY 555The idea that terra preta is formed as a re-sult of human activities is more widely ac-cepted. According to one version of this the-ory, black soil is formed in aboriginal gardenplots, presumably as a result of burningslash.10This explanation does not account forthe depth of dark soil, up to 2 m in some cases,since burning forest or second growth woulddeposit only a thin layer of ash on the soil. Inthe swidden system, the predominant farmingpattern of natives in Amazonia, a plot isburned once, cropped a few years, then aban-doned. The ash is soon carried away in run-off or leached.It has been suggested that black earth wasformed in Indian fields due to the incorpora-tion of bones and organic matter.1 But thereis no evidence that natives applied organic fer-tilizers to their fields in Amazonia; it is notpracticed today. None of the theories so faradequately account for the presence of sherdsin terra preta (Fig. 1).Black earth localities are usually consideredto be a cultural layer accumulated at formerIndian villages.2 Terra preta is attributed to10 G. Prance and H. Schubart, "Nota Preliminar sobrea Origem das Campinas Abertas de Areia Branca do Bai-xo Rio Negro," Acta Amazonica, Vol. 7 (1977), No. 4,pp. 567-70; and G. Prance and H. Schubart, "Notes onthe Vegetation of Amazonia I. A Preliminary Note on theOrigin of the Open White Sand Campinas of the LowerRio Negro," Brittonia, Vol. 30 (1978), No. 1, pp. 60-63.11Bennema, op. cit., footnote 3, p. 32.12 W. Farabee, "Explorations at the Mouth of the Am-azon," Museum Journal, Vol. 12 (1921), No. 3, pp. 142-61; C. Nimuendaju, "Tribes of the Lower and MiddleXingi River," in J. Steward, ed., Handbook of SouthAmerican Indians (Washington: Smithsonian Institution,1948), pp. 213-43; P. Gourou, "Observag6es Geogrdficasna Amaz6nia," Revista Brasileira de Geografia, Vol. 11(1949), No. 3, pp. 355-408; P. Hilbert, "A Ceramica Ar-queol6gica da Regido de Oriximind," Publica!1io do In-stituto de Antropologia e Etnologia do Pard, Vol. 9(1955), pp. 1-76; H. Sternberg, "Radiocarbon Dating asApplied to a Problem of Amazon Morphology," ComptesRendus du XVIII Congres International de Geographie,Vol. 2 (1960), pp. 399-424; H. Klinge, "Beitrdge zurKenntnis Tropishcer Boden V. Uber Gesamtkohlenstoffund Stickstoff in Bdden des Brasilianischen Amazonas-gebietes," Z. Pflanzenerndhr. Duing. Bodenk., Vol. 97(1962), No. 2, pp. 106-18; G. Ranzani, T. Kinjo, and 0.Freire, "Ocorrencias de Plaggen Epipedon no Brasil,"Escola Superior de Agricultura Luiz de Queiroz, Univer-sidade de Sdo Paulo, Piracicaba, Boletim Tecnico, Vol.5 (1962), pp. 1-12; W. Sombroek, Amazon Soils: A Re-connaissance of the Soils of the Brazilian Amazon Region(Wageningen: Center for Agricultural Publications andDocumentation, 1966); and B. Meggers and C. Evans,"An Interpretation of the Culture of Maraj6 Island," in,W, ArpU- i0: 8poshrd, Itcair, mznsof refuse.Objections to the anthropogenicor-~~~~~~~~~...........FIGinofAtrooe black earthhae fee rIsedt onithegrounds that there is insufficient water on theBelterra plateau to support year-round humanoccupation.13 Although streams are virtuallyabsent on the plateau, the now extinct TapaJ6tribe dug wells for water, some of which arestill in use by peasants.14 Black earth is stillbeing formed today; a darkening of the soilcan be noted in backyards of towns in the re-gion, and an enrichment of the soil around vil-lages is also noted in northeastern Thailand.15But the rate of black earth formation is prob-D. Gross, ed., Peoples and Cultures of Native SouthAmerica (New York: Natural History Press, 1973), pp.39-47.13 Cunha Franco, op. cit., footnote 8.14 C. Nimuendaju, "Os Tapaj6," Boletim do MuseuGoeldi, Vol. 10 (1949), pp. 93-106.15 R. Pendleton, "Land Use in Northeastern Thai-land," Geographical Review, Vol. 33 (1943), pp. 15-41.
556 NIGEL J. H. SMITH DecemberTABLE 1.-ANALYSIS OF ANTHROPOGENIC BLACK EARTH IN THE BRAZILIAN AMAZONaTexture % % Exchangeable bases mE/100 g Cation Base% Nitro- mg/100 g exchange satura- H20Site Sand Silt Clay Carbon gen P205 Ca Mg K Sum Al capacity tion pH1 77 18 5 1.77 0.14 10.99 - - 0.60 10.02 0.00 10.02 100 7.92 52 27 21 1.41 0.11 0.54 3.00 1.90 0.30 5.22 0.40 10.50 50 4.93 55 22 23 1.84 0.14 16.90 4.60 1.20 0.04 5.87 0.40 10.65 55 5.34 68 21 11 1.73 0.08 89.00 6.20 0.59 0.23 7.06 0.10 12.01 59 5.65 72 17 11 1.26 0.09 0.49 3.85 0.61 0.05 4.54 0.20 10.31 44 5.46 71 16 13 2.06 0.18 1.17 4.14 0.78 0.09 5.04 0.00 12.79 39 5.57 81 17 2 0.87 0.05 0.52 0.19 0.02 0.01 0.23 1.60 7.16 3 4.28 40 35 25 1.65 0.16 119.60 6.80 0.60 0.10 7.54 0.00 13.31 57 5.39 8 44 48 3.50 0.46 33.00 10.00 1.94 0.12 12.09 0.00 18.69 65 5.610 10 55 35 2.50 0.32 35.00 10.00 2.91 0.42 13.40 0.00 19.17 70 5.611 66 11 23 1.14 0.12 0.60 0.72 0.28 0.05 1.07 1.04 9.31 11 4.612 37 38 25 2.13 0.23 14.55 10.08 1.04 0.56 11.71 0.14 15.29 77 6.213 86 3 11 0.45 0.06 15.30 0.80 0.48 0.05 1.36 0.85 6.02 23 4.614 66 10 24 0.71 0.08 139.20 5.20 0.48 0.16 5.89 0.15 9.83 60 6.115 22 30 48 3.11 0.31 154.80 15.28 2.88 0.11 18.35 0.18 23.90 77 5.916 66 13 21 0.81 0.20 14.65 4.56 0.48 0.16 5.21 0.05 5.88 89 7.017 38 38 24 2.71 0.26 48.00 11.92 0.72 0.45 13.10 0.07 18.13 72 5.918 83 5 12 1.11 0.07 2.80 0.22 0.99 0.01 1.23 0.99 7.11 17 4.619 65 19 16 2.70 0.18 30.00 1.21 0.55 0.06 1.84 0.79 10.83 17 4.620 96 3 1 0.76 0.05 0.26 0.11 0.33 0.01 0.46 0.69 3.81 12 4.321 86 4 10 0.67 0.07 7.76 0.22 0.77 0.03 1.03 1.19 4.46 23 4.622 80 5 15 1.25 0.09 0.32 0.22 0.50 0.07 0.81 0.99 5.47 15 4.623 19 36 45 4.70 0.34 30.00 10.20 2.77 0.21 13.21 0.10 19.09 69 5.724 86 7 7 2.09 0.12 1.13 1.83 0.37 0.03 2.25 0.30 9.20 24 5.425 72 8 20 1.12 0.08 37.60 2.51 1.15 0.04 3.72 0.30 9.28 40 5.426 55 22 23 1.91 0.16 32.60 5.23 0.63 0.06 5.95 0.10 11.43 52 5.327 68 14 18 1.48 0.10 315.00 7.18 0.31 0.07 7.68 0.19 11.58 66 5.528 69 20 11 1.30 0.08 0.41 1.67 0.42 0.08 2.21 0.74 8.32 27 4.529 74 10 16 1.50 0.11 10.90 3.64 0.93 0.11 4.71 0.16 8.61 55 5.5a Phosphorus figures are available P. To convert to ppm, multiply mg/100 g by 4.366. See footnote 19.ably slower at present; pigs and chickens, un-known to Indians in precontact times, con-sume large amounts of kitchen middens, andmost fires are built above ground.PHYSICAL AND CHEMICAL PROPERTIES OFANTHROPOGENIC BLACK EARTHThe dark color of terra preta is the moststriking feature of the soil; it stands out amongthe predominant yellow and red soils of thebasin. Unlike in temperate areas, peaty soilsare very rare in Amazonia. The color rangesfromjet black to dark gray-brown and is prob-ably related to the time the site was occupied;the darker the soil, the longer the locality wasinhabited. The stability of the dark color, evenafter prolonged exposure to the hot sun andtorrential rains, is remarkable. The inky coloris most likely due to a complex formation oforganic matter and calcium ions that form acoating on the soil particles.16 It is not clear,16 Sombroek, op. cit., footnote 12, p. 253.though, why the dark color is so persistent.Organic compounds, such as phenols, areprobably binding carbon to soil colloids.The dark color is due largely to residue fromfires. Many Indian villages have a clearedspace, usually in the middle, which is keptclean for ceremonial events. Refuse is com-monly deposited at the perimeter of the settle-ment.17 If terra preta is due primarily to rub-bish accumulation, then one would expect thesoil to be built up around the village in donutfashion. But organic matter rapidly disinte-grates in the warm, moist climate. Further-more, black earth is not found in mounds, ex-cept on Maraj6 Island where the formeroccupants heaped earth to escape the water-logged conditions duringthe rainy season. Thedeepest portion of Indian black earth sites thatI have seen is in the middle, gradually becom-17 T. Myers, "Toward Reconstruction of PrehistoricCommunity Patterns in the Amazon Basin," in D. Lath-rap and J. Douglas, eds., Variation in Anthropology (Ur-bana: Illinois Archaeological Survey, 1973), pp. 233-52.
1980 ANTHROSOLS AND CARRYING CAPACITY 5571600W 1500w00 T UARAFIG.S 2.Loaiosofalakeat ste amld nth Ara nA moTACOATIARA ~ ~ MRAB*TOWNSHIGHWAYS* ANTHROPOGENICBLACKEARTH SITE0 500 kmFIG. 2. Locations of anthropogenic black earth sites sampled in the Brazilian Amazon.ing shallower toward the edge, in lens fash-ion. Natives often keep several fires burningat all times to cook and keep warm, as well asto ward off evil spirits at night.18 Over de-cades, and in some cases probably centuriesor millennia, incomplete combustion aroundlow-heat fires would produce carbon-richhearths. The carbon content of twenty-nine18A. Metraux, "The Tupinamba," in J. Steward, ed.,Handbook of South American Indians (Washington:Smithsonian Institution, 1948), Vol. 3, pp. 95-133; C.Nimuendaju, "The Cawahib, Parintintin, and TheirNeighbors," in J. Steward, ed., Handbook of SouthAmerican Indians (Washington: Smithsonian Institution,1948), Vol. 3, pp. 283-97; J. Steward and A. Metraux,"Tribes of the Peruvian and Ecuadorian Montania," in J.Steward, ed., Handbook of South American Indians(Washington: Smithsonian Institution, 1948), Vol. 3, pp.535-656; Meggers (1971), op. cit., footnote 1, p. 98; M.Harner, The Jivaro: People of the Sacred Wateifalls(New York: Anchor Press, 1973); and W. Smole, TheYanoama Indians: A Cultural Geography (Austin: Uni-versity of Texas Press, 1976), p. 65.sampled black earth sites was relatively high,averaging 1.73% (s = 0.95, Table 1, Fig. 2).19Black earth sites occur on a variety of soiltypes, including latosols (oxisols), podzolicsoils (ultisols), terra roxa eutr6fica (eutrophicoxisols) and podzols (spodosols) (Table 2).2?It thus seems unlikely that terra preta wouldresult from natural soil forming processes.The texture of sampled black earth rangesfrom silty clay to almost pure sand. In all tex-ture classes, the first few centimeters of top-soil have become sandier as a result of humanoccupation of the site. The exposed condition19Only black earth with potsherds was sampled. Ateach site a composite sample was gathered from fifteenrandomly selected sublocations and then mixed. Blackearth was sampled to a depth of 20 cm. For characteristicsof each site, see Table 2.20 Bennema, op. cit., footnote 3, states that Indianblack earth occurs on kaolinitic yellow latosols but doesnot mention that it is also found in other soil types.
TABLE2.-LOCATION ANDCHARACTERISTICSOFSAMPLEDANTHROPOGENICBLACKEARTHSITESBlackBlack earthearth max. SurroundingSite Location Vegetation area ha depth m soil type ObservaI Gleba 24, lot 20, km 77 Arara Indian field 4 1.5 0.40 Terra roxa Sherds abundaAltamira-Itaituba, yrs old to depth of 1Transamazon, Pard. roughly circuPerennial stream 300 maway.2 Gleba 34, lot 17, km 105 Colonist field in 5.0 0.20 Red- Sherds found bAltamira-Itaituba, coffee, 1 yr old, yellow depth, stoneTransamazon, Para. cleared from latosol roughly circuPerennial stream 300 m mature forestaway.3 Agropolis Miritituba, right Open area in weeds, 10.0 0.20 Yellow Sherds and stobank of Tapaj6s River, cleared from latosol on surface anPard. secondary forest cm. Site strebank and 104 Itupiranga, left bank of Open area in grass 4.0 0.70 Red- Sherds and celtTocantins River, Pard. and mango trees yellow to depth of 5podzolic5 Gleba 24, lot 26, sideroad km Open area by 1.0 0.40 Yellow Sherds on surf80 Altamira-Itaituba, COBAL store, latosol of 10 cm. SitTransamazon, Pard. cleared from forest in shape.Perennial stream 400 m 2 yrs agoaway.6 Gleba 31, lot 12, sideroad km Mature forest 0.5 0.87 Terra roxa Sherds at 15 cm100 Altamira-Itaituba roughly circuTransamazon, Pard.Perennial stream 200 maway.7 Km 139 Itacoatiara-Manaus, Campina 0.5 0.20 Podzol Sherds frequenAmazonas. Perennial to depth of 2stream 300 m away. lenticular in8 Atlantic veneer mill, Open weedy area 30.0 1.00 Yellow Sherds abundaItacoatiara, left bank of latosol frequent onAmazon River, Amazonas. depth of 10 ckm along baninland.9 Lago de Terra Preta, 30 km Maize and squash 0.8 0.45 Red Sherds on surfS.E. of Itacoatiara, field 2 yrs old. latosol depth. Site eAmazonas. Bluff Cleared from 2nd along marginoverlooking blackwater growth inland.lake.
TABLE 2.-CONTINUED.BlackBlack earthearth max. SurroundingSite Location Vegetation area ha depth m soil type Observation10 Entrance to Lago de Batista, Cacao grove some 40 0.4 0.4 Yellow Sherds at 10 cm d25 km S.E. of Itacoatiara, yrs old latosol extends 50 m aloAmazonas. Bluff lake and 80 m inoverlooking blackwaterlake.11 Km 2 Aripuana-Colonia dos Mature forest 0.5 0.20 Latosol Sherds and celts toPatos, northern Mato Site roughly circGrosso. Perennial stream500 m away.12 Aripuana, right bank of Open, town streets 24.0 0.50 Yellow Sherds and celts fAripuana River, northern and square latosol cm depth. Site lMato Grosso. shape.13 Lago de Madruba, 6 km Open grassland 0.5 0.50 Podzol Sherds numerousnorth of Itapiranga, Am. depth. Site extenMargin of blackwater lake. along margin ofinland.14 Itapiranga, left bank of Open backyard 8.0 1.00 Yellow Sherds abundant oParand Silves, Amazonas. latosol to depth of 50 cextends 800 m a100 m inland.15 Terra Nova, Parand do I yr 2nd growth 45.0 0.90 Yellow Sherds common oSilves, 1 km west of latosol to 50 cm depth.Itapiranga, Amazonas. for 1.5 km alongm inland.16 Gleba 24, lot 8, km 74 Manioc field 0.3 0.15 Podzol Sherds abundant oAltamira-Itaituba, to 15 cm depth.Transamazon, Pard. in shape.Perennial stream 30 maway.17 Missdo, left bank of Xingu Open area with weeds 90.0 0.68 Yellow Sherds and celts aRiver, 1.8 km south of latosol surface and to 1Altamira, Pard. Site extends 1.8bank and 500 m18 Praia Dourada, Tarumd Open grassland with 3.2 1.47 Yellow Sherds abundant tRiver, 15 km N.W. of weeds podzolic Celts. Site extenManaus, Am. Blackwater along river andRiver.19 Tapurucuara, Rio Negro, Open grassland 7.0 1.09 Red- Sherds common oAmazonas. yellow to depth of 85 cpodzolic extends 700 m a100 m inland.
TABLE 2.-CONTINUED.BlackBlack earthearth max. SurroundingSite Location Vegetation area ha depth m soil type O20 Campina, estrada de Terra Campina 1.0 0.24 Podzol Sherds onPreta, sideroad at km 4 depth. SCacau Pirera-Manacapuru,Am. Margin of perennialstream.21 Km 4 Cacau Pirera- Early 2nd growth 4.0 0.84 Red- Sherds abuManacapuru, Am. Margin yellow to 70 cmof perennial stream. podzolic lenticula22 Estrada de Terra Preta, Campinarana forest 0.5 0.20 Podzolic Sherds infrsideroad at km 4 Cacau to 20 cmPirera-Manacapuru, Am.Perennial stream 200 maway.23 Ponta das Lajes, Rio Negro, 2nd growth of several 6.0 0.25 Yellow Sherds abuManaus, Amazonas. years latosol 25 cm dm alonginland.24 Km 8 Ponta Negra road, Campinarana 35.1 1.41 Podzol Sherds infManaus, Amazonas. to 5 cm2.7 km ainland.25 Ceramica Irco, km 15 Aleixo Grassland 0.8 0.50 Yellow Sherds aburoad, Manaus, Am. Bluff podzolic Site exteoverlooking Amazon. and 60 m26 Manacapuru, Amazon River, 2nd growth of several 80.0 1.00 Yellow Sherds abuAmazonas. years latosol depth. Sbank an27 Itaituba, Tapaj6s River, Pard. Open, bare ground 15.0 0.45 Yellow Sherds rarlatosol cm deptalong ba28 Gleba 12, lot 7, km 30 Backyard weeds, 0.7 0.35 Podzolic Sherds numAltamira-Maraba, cleared from forest 10 cm dTransamazon, Pa. Margin 8 yrs agoof perennial stream.29 Km 30 Itaituba-Altamira, Open, bulldozed 1.6 0.25 Latosol Sherds numjunction of Transamazon 15 cm dand Cuiabd-Santaremhighways, Pa. Perennialstream 200 m away.
1980 ANTHROSOLS AND CARRYING CAPACITY 561of a village promotes the mechanical eluvia-tion of clay to lower horizons. In test plots ofnon-terra preta soils along the Transamazonhighway, the top 5 centimeters became slight-ly, but significantly, sandier within three yearsof exposure.21 The fact that black earth sitesare found on podzols is at variance with theidea that they were formed as a result of ag-ricultural activities. Sandy soils in Amazoniaare especially poor in nutrients. Still, a podzolwould provide a convenient habitation site ifthere were suitable agricultural soils in the vi-cinity since it would be much less muddy inthe rainy season.One of the indicators of former human oc-cupation of a site is the fertility of the soil.Generally, upland Amazonian soils are poorin nutrients because of prolonged leaching andbecause the weathering front of the geologicalsubstrate is too deep to provide nutrients forplants. Fires would liberate nutrients into thesoil and the break down of kitchen middenswould also contribute potash, phosphorus,calcium and nitrogen. Whereas in archeologi-cal sites in California, human urine and excre-ment are considered important sources of nu-trients, they are probably only a minor sourcein black earth sites of Amazonia.22 Adult In-dians generally retire into the bush or forestto eliminate metabolic wastes; small childrenwould contribute a few nutrients to the soil bydefecating and urinating promiscuously withinthe village.Phosphorus, in particular, is considered oneof the most significant elements indicatingformer human occupation of a site.23 Phos-phates are often in short supply in Amazoniansoils. Whereas in oxisols and ultisols, which ac-count for the majority of Amazonian soils, theavailable phosphorus content is usually under5 mg/100 g, in the sampled Indian black earths21 N. Smith, Transamazon Highwiay: A Cultural-Eco-logical Analysis of Settlement in the Humid Tropics, un-published doctoral dissertation, University of California,Berkeley, 1976.22 A 70 kg male daily eliminates, in feces and urine,14.5 g of nitrogen, 2.5 g of phosphorus and 0.9 g of cal-cium; S. Cook and A. Treganza, "The Quantitative In-vestigation of Indian Mounds with Special Reference tothe Relation of the Physical Components to the ProbableMaterial Culture," University of California Publicationsin American Archaeology and Ethnology, Vol. 40 (1950),No. 5, pp. 223-62.23 R. C. Eidt, "Detection and Examination of Anthro-sols by Phosphate Analysis," Science, Vol. 197 (1977),No. 4311, pp. 1327-33.it averaged 40.1 mg/100 g (s = 67.7), and inone case it reached 315 mg/100 g (Table 1).The lowest quantities of phosphorus in thesampled terra preta are found in the sandiersoils; leaching and phosphorus fixation in theform of iron and aluminum phosphates prob-ably are responsible. It seems likely that sitesabandoned long ago also would lose phos-phorus.In an analysis of Indian black earth fromfive sites, Sombroek found phosphorus levelsranging from 6.9 to 99 mg/100 g, also from 0to 20 centimeters deep.24 Other published re-sults of terra preta analyses reveal a phos-phorus content of 32.4 mg/100 g soil to a depthof 30 centimeters,25 24.0 mg/100 g to a depthof 8 centimeters,26 and 1.4 and 11.7 mg/100 gin two black earths sampled to a depth of 10centimeters.27 Ash from fires, bones from fishand game animals, feces, urine, and turtleshells account for the relatively high levels ofphosphorus in black earth. In some cases, hu-man bones may also have contributed to thephosphorus content of terra preta; the Tapi-rap6, for example, used to bury their kin with-in their homes, and the Xikrin practice sec-ondary burial of human bones in theirvillage.28Calcium levels in sampled anthropogenicepipedons are also generally high, averaging4.7 mg/100 g of soil (s = 4.1, Table 1). Som-broek also found unusually high levels of cal-cium in five terra preta soils sampled, rangingup to 25 mg/100 g of soil.29Animal and humanbones would account for some of the concen-tration of the element at black earth sites. Be-cause calcium levels are generally high, basesaturation is usually moderate to high, aver-aging 47.2% (s = 25.9). The pH of sampled24Sombroek, op. cit., footnote 12, p. 256.25 J. Falesi, "Solos de Monte Alegre," Instituto de Pes-quisas e Experimentagdo Agropecuarias do Norte, Be-lem, Serie Solos da Amaz6nia, Vol. 2 (1970), No. 1, pp.1-127.26 B. Silva, J. Araujo, I. Falesi, and R. Rego, "Os Solosda Area Cacau Pirera-Manacapuru," Instituto de Pes-quisas e Experimentagao Agropecuarias do Norte, Be-lem, Serie Solos da Arnaz6nia, Vol. 2 (1970), No. 3, pp.1-198.27 Ranzani et al., op. cit., footnote 12.28C. Wagley, Welcome of Tears: The Tapirape Indiansof Central Brazil (New York: Oxford University Press,1977), p. 173; and L. Vidal, Morte e Vida de Uma Socie-dade Indigena Brasileira (Sao Paulo: Editora Hucitec-Editora da Universidade de Sao Paulo, 1977), p. 174.29Sombroek, op. cit., footnote 12, p. 253.
562 NIGEL J. H. SMITH Decemberblack earth sites averaged 5.4 (s = 0.8),whereas the pH of oxisols and ultisols inAmazonia is usually under 5. Below pH 5.5,the activity of soil bacteria and actinomycetes,as well as the availability of nutrients such asnitrogen, calcium, magnesium, potash, phos-phorus, and sulphur, are sharply reduced.30Aluminum levels of the sampled black earthsites generally were moderate to low, aver-aging 0.4 mg/100 g (s = 0.4). Levels in excessof 1.0 mg/100 g are not uncommon in oxisolsand ultisols in Amazonia, and can be toxic tocrop plants.UTILIZATION OF ANTHROPOGENICBLACK EARTHThe superior fertility of Indian black earthis widely appreciated throughout Amazonia.31Aboriginal groups, such as the Mundurucii ofthe upper Tapaj6s River and the Xikrin of theItacaiunas River, recognize the soil as espe-cially valuable for agriculture.32The Maw6 In-dians favor anthropogenic epipedon to growguarandvines (Paullinia cupana), the fruits ofwhich are roasted and prepared into a refresh-ing regional drink.33On the Belterra plateau the numerous blackearth sites are sought out by civilized Indiansand peasants for farming, though in somecases the abundant sherds create a nuisance.34Peasants favor anthropogenic black earth fortheir garden plots along the Trombetas andJamundai rivers.35 Terra preta do indio is re-puted to be particularly good for growing fruittrees, cacao, bananas, and vegetables.36 Some30 N. Brady, The Nature and Properties of Soils (NewYork: MacMillan, 1974), p. 388.31 L. Castro Soares, Amazonia (Rio de Janeiro: Inter-national Geographical Union, Excursion Guidebook 8,1956), p. 67.32 P. Frikel, "Agricultura dos Indios Mundurukiu,"Bol-etim do Museu Goeldi, N.S., Antropologia, Vol. 4 (1959),pp. 1-35; and idem, "Os Xikrin," Publicaqaoes Avulsasdo Museu Goeldi, Vol. 7 (1968), pp. 3-119.33 N. Pereira, Panorama da Alimentaqiio Indigena:Comidas, Bebidas e T6xicos na Amaz6nia Brasileira (Riode Janeiro: Livraria Sao Jose, 1974), p. 31.34 C. Hartt, "Contribui96es para a Ethnologia do Valledo Amazonas," Archivos do Museu Nacional, Vol. 6(1885), pp. 1-174; F. Barata, "A Arte Oleira dos Tapaj6,"Publicaqcio do Instituto de Antropologia e Etnologia doPard, No. 2 (1950), pp. 1-47; Cunha Franco, op. cit.,footnote 8; and Nimuendaju, op. cit., footnote 14.35 Faria, op. cit., footnote 9; and Hilbert, op. cit., foot-note 12.36 Camargo, op. cit., footnote 4; Gourou, op. cit., foot-note 12; and Silva et al., op. cit., footnote 26.authors claim that rubber trees (Hevea bras-iliensis) do not fare well on black earth.37Som-broek asserts, however, that the trees aremore resistant to the highly-destructive fungalleaf blight (Microcyclus ulei) on the soil.38Anthropogenic black earth is in brisk de-mand in urban areas for spreading on yards topromote the growth of grass, ornamentalplants, and vegetables. In Manaus, black earthis trucked from sites along the Amazon Riveras far as 40 km away and is sold for U.S. $100per 4-ton load. In Altamira on the Xingu Riv-er, vehicles bring in black earth from the pe-riphery of town for yards of public buildings,such as the new federally operated hospital.In the Amazon River town of Itacoatiara,mule-drawn carts are loaded with terra pretafrom waste lots within town and distributed toupper class homes. Because of the widely ac-claimed agricultural value of Indian blackearth, and the favorable location of the sites,many of the sites have been heavily disturbed,rendering archeological studies difficult.CHARACTERISTICS OF ANTHROPOGENICBLACK EARTH SITESMost known Indian black earth sites arealong rivers. In the case of silt-laden watercourses, a fertile floodplain provides bountifulharvests and plenty of fish, turtles, and, for-merly, manatees for protein. Early expedi-tions into the Amazon basin, such as that ofOrellana in 1542, traveled along major riversand often encountered dense native popula-tions.39But surprisingly, twelve of the twenty-nine sampled black earth sites are in uplandareas.Since terra preta with sherds is of anthro-pogenic origin, one would expect the sites tobe advantageous for human settlement. A no-table feature of the sampled black earth sitesis that they are either on the bank of a peren-nial water course, or within a few hundredmeters of one (Table 2). Along rivers, blackearth sites are often found just above falls,such as Vila Aripuand by Cachoeira dos An-dorinhos on the Aripuand River or just above37 Gourou, op. cit., footnote 12; and Silva et al., op.cit., footnote 26.38 Sombroek, op. cit., footnote 12, p. 252.39 J. Medina, The Discovery of the Amazon Accordingto the Account of Friar Gaspar de Carvajal and OtherDocuments (New York: American Geographical Society,1934).
1980 ANTHROSOLS AND CARRYING CAPACITY 563rapids, such as at Altamira on the Xingu (Fig.2). Along the Rio Negro, black earth almostinvariably occurs wherever a slab of graniticrock juts into the water. Such sites would pro-vide convenient work benches for grindingfoodstuffs and stone tools. The ready avail-ability of potable water, then, is one of themost important characteristics of terra pretasites.Many black earth sites are occupied by neo-Brazilian communities. The advantages of thesites persist. According to the Mapa da BaciaAinazonica published on a scale of 1:1,500,000,four communities in the Brazilian Amazon arecalled Terra Preta.40Three are in Amazonasstate along the Abacaxis, Canuma, and Ari-puana rivers, and one is in Pard state alongthe Tapaj6s River. In Manacapuru, an Ama-zon River town 80 km west of Manaus, a sub-urb called Terra Preta rests on one of the mostextensive black earth sites so far discoveredin Amazonia.Black earth sites along rivers are usuallylarger, and more linear in shape, than thoseencountered in interfluve areas. Site 17, nearAltamira on the clearwater Xingu, stretches1.8 km along the left bank of the river and 500m inland, thereby covering 90 ha. Site 26 atManacapuru on the banks of the muddy Am-azon extends 4 km along the margin of theriver and 200 m inland. Only recently has thetown of 18,000 grown beyond the boundariesof the 80 ha site. The elongated pattern of thesites suggests linear settlement. Since in manycases the black earth extends several hundredmeters inland, there must have been numer-ous dwellings, not just a single row of huts.Black earth sites sampled along rivers aver-aged 21.2 ha (s = 27.5).In interfluve areas, the twelve sampled terrapreta sites were all under 6 ha and averaged1.4 ha (s = 1.5). Upland sites are roughly cir-cular or lenticular in shape. Such sites wereoccupied by either a large central communalhouse (mnaloca), or several houses in one ormore circles. The shape and area of blackearth sites encountered in the Brazilian Am-azon by other investigators are close to therange that I have found (Table 3). Althoughinterfluvial black earth sites are generallysmall, in some areas they are numerous. Terrapreta is estimated to cover some 50,000 ha40 Published by the Instituto Brasileiro de Geografia eEstatistica, Rio de Janeiro (1971).TABLE 3.-RANGE OF AREAS OF SOME ANTHROPOGENICBLACK EARTH SITES IN THE BRAZILIAN AMAZONArea (ha) Shape Location2-12 Circular to Belterra plateaualenticular2-4 No description Trombetas andJamundd rivers)<3 Circular Belterra plateauc2-3 Lenticular Belterra plateau0.2-0.4 No description Maraj6, CavianaIslandse0.03-0.07 Circular or oval North centralMaraj6 Island1-8 No description Trombetas Riverg80 Linear ManacapuruhFalesi, op. cit., footnote 25.Faria, op. cit., footnote 9.Cunha Franco, op. cit., footnote 8.dGourou, op. cit., footnote 12.Evans, op. cit., footnote 44.Evans, op. cit., footnote 44.Hilbert, op. cit., footnote 12.h P. Hilbert, Arclhiiologi.sche Untersuchlungen am Mittleren Amazonas(Berlin: Dietrich Reimer Verlag, 1968), p. 122.between the Tapaj6s and Curud-Una riversalone.4Most anthropogenic black earth sites areless than 1.5 m deep, though 2 m has beenrecorded (Table 4). The seventeen black earthsites sampled in riverine areas are an average0.73 m (s = 0.38) deep, whereas the twelvesites sampled in interfluvial areas averaged0.36 m deep (s = 0.25, Table 2). Both terrafirme and floodplain environments, then, wereinhabited by sedentary aboriginal groups inprecontact times.DISCUSSIONIt is difficult to estimate how large a popu-lation inhabited each black earth locality. Na-tive buildings were, and still are, made fromwood and palm fronds that soon disintegrate.Another problem is that aboriginal cultures inthe region use different village plans, rangingfrom a large communal house to a circle ofdwellings. The large riverine terra preta sitesmay have been occupied for various periodsby different groups, each time deepening andpossibly extending the area of stained earth.But the entire area of even the largest sitesmay have been settled at one time; the 80 ha41 F. Katzer, "A Terra Preta," Boletim da Secqdo deFomento Agricola no Estado do Parid, Vol. 3 (1944), No.2, pp. 35-38.
564 NIGEL J. H. SMITH DecemberTABLE 4.-MAXIMUM DEPTHS OF SOME ANTHROPOGENICBLACK EARTH SITES IN THE BRAZILIAN AMAZONMaximum depth (m) Location2.0 Lower Amazona1.5 Belterra plateau"1.5 Oriximina, Parde1.2 Belterra plateau1.0 Maraj6 Islande1.0 Belterra plateau0.6 Trombetas Riverg0.5 Belterra plateaUhKatzer, op. cit., footnote 41.Nimuendaju, op. cit., footnote 24.Falesi, op. cit., footnote 24.d Cunha Franco, op. cit., footnote 8.Evans, op. cit., footnote 44.Sombroek, op. cit., footnote 12.9 Hilbert, op. cit., footnote 12.h Gourou, op. cit., footnote 12.Manacapuru site could have been occupied byas many as 18,000 Indians.42Although upland black earth sites generallyare smaller than riverine ones, they neverthe-less could have been occupied by largegroups. A native long-house measuring 34 by24 meters can shelter at least 100 people; Wi-toto malocas that measured 100 by 50 meterssheltered a community of 400.43 Terra pretamounds on Maraj6 Island, once occupied byIndians of the Ananatuba phase, ranged from0.03 to 0.07 ha and were the sites of communalhouses each sheltering from 100 to 150 indi-viduals.44 The interfluvial black earth sites Isampled range from 0.3 to 5 ha. They wereonce occupied by villages containing from 100to 2,000 inhabitants.The depth of black earth is undoubtedly cor-related with the length of time the site wasinhabited, but it is not known how fast ths oilwas formed. In the case of Maraj6 Island, 1m depth of terra preta has been assumed torepresent approximately 100 years of occu-pation.45 It seems unlikely that black earthwould have formed that quickly consideringthe rapid rates of organic matter decomposi-tion. A rate of 1 centimeter of terra preta per10 years of settlement is more likely.42Myers, op. cit., footnote 17.43 R. Lowie, "The Tropical Forests: An Introduction,"in J. Steward, ed., Handbook of South American Indians(Washington: Smithsonian Institution, 1948), Vol. 3, p.17; and Myers, op. cit., footnote 17.44 C. Evans, "Lowland South America," in J. Jenningsand E. Norbeck, eds., Prehistoric Man in the New World(Chicago: University of Chicago Press, 1964), pp. 419-50.45 Evans, op. cit., footnote 44.If 1 centimeter of black earth was createdevery 10 years, then 2 meters of the soil wouldrepresent some 2,000 years of settlement. Astudy of sherds from black earth sites 5 and6 along the Transamazon highway reveals thepresence of at least two, and possibly three,wares at each locality.46 Several differentwares at a site does not necessarily mean thatthe locality was abandoned and occupied bydifferent groups; the wares could be transi-tional, or trade items. If a 2 meter black earthsite was not continuously settled, it couldhave been first occupied tens of thousands ofyears ago.The oldest date so far for pottery in the Bra-zilian Amazon is 980 BC ? 200 years, fromcharcoal associated with Mangueiras phasesherds on Maraj6 Island.47The earliest ceram-ic date for the Ucayali River in the PeruvianAmazon is 650 BC ? 100 years.48 Some ar-cheological sites along the Ucayali have beenoccupied as many as eighteen times with anaverage stay of 100 years. There have beenrelatively dense settlements along the Ucayaliand other rivers of Amazonia for at least 4,000years.49In many terra preta sites, sherds do not al-ways extend to the bottom of the profile; it ispossible that preagricultural folk once inhab-ited some of the sites. Leaching of carbonmight account for some, but not all, of theblack earth in the lower profile without ce-ramics. Man has been in South America for atleast 22,000 years, and in the Brazilian statesof Goias, Pernambuco, Minas Gerais, andMato Grosso for a minimum of 10,000 years.5046 W. DeBoer, N. Smith, D. Haarmann, and M. Veale,"Notes on Collections of Ancient Ceramics from the Al-tamira Area, State of Par," mimeographed, n.d.4 M. Sim6es, "The Castanheira Site: New Evidenceon the Antiquity and History of the Ananatuba Phase,"American Antiquity, Vol. 34 (1969), pp. 402-10.48 D. Lathrap, "Aboriginal Occupation and Changes inRiver Channel on the Central Ucayali, Peru," AmericanAntiquity, Vol. 33 (1968), pp. 62-79.49 D. Lathrap, The Upper Amazon (New York: Prae-ger, 1970).50 R. MacNeish, "Early Man in the Andes," ScientificAmerican, Vol. 224 (1971), pp. 36-46; H. Walter, Ar-queologia daiRegido de Lagoa Santa (Minas Gerais): In-dios Pre-Colombianos dos Abrigos Rochedos (Rio de Ja-neiro: Sedegra, 1958); 0. Fonseca, "Parasitismo eMigragdes Humanas Pr&Hist6ricas," in P. Duarte, ed.,Estudos de Pre-Hist6ria Geral e Brasileira (Sdo Paulo:Instituto de Pr6-Historia da Universidade de Sdo Paulo,1969), pp. 1-346; and B. J. Meggers, "Climatic Oscillationas a Factor in the Prehistory of Amazonia," AmericanAntiquity, Vol. 44 (1979), pp. 252-66.
1980 ANTHROSOLS AND CARRYING CAPACITY 565Amazonia with its abundant fish, turtles, in-sects, and fruits would have provided a corn-ucopia for early hunters and gatherers. Thereis no ecological reason why they might nothave lived in the region, and built campfires,for as long as they have in Minas Gerais, orany other part of South America.Objections have been raised that aboriginalpopulations were too sparse and transitory tohave been responsible for terra preta. It isclaimed that Indian settlements are unlikely toexceed 200 individuals in upland areas withmanioc as a basic staple.5 On the other hand,it has been convincingly argued that a tribe of2,000 can remain sedentary on terrafirtme bycropping the highly productive tubers in aswidden system within a 6.4 km radius of thevillage.52 The fact that no Indian villages inAmazonia attain such a size now does notmean they did not in the past. In 1824, evenafter a century of intermittent contact withLuso-Brazilians, and at least one smallpox ep-idemic, three Apinaye villages on the inter-fluve between the Tocantins and Araguaiacontained 1,000 individuals each or more.The largest sheltered 1,600.The alleged shortage of protein sources inthe interfluvial forests of Amazonia has beenhighlighted as a major factor restricting thesize and permanence of aboriginal groups.Game is apparently rapidly depleted in the vi-cinity of a village, and the group must moveon to a fresh area in order to survive.54 Large51 Camargo, op. cit., footnote 4; and E. Galvdo, "Ele-mentos Bdsicos da Horticultura de Subsistencia Indi-gena," Revista do Museu Paulista, N.S., Vol. 14 (1963),pp. 120-44.52 R. Carneiro, "Slash-and-Burn Agriculture: A CloserLook at its Implications for Settlement Patterns," in A.Wallace, ed., Men and Cultures (Philadelphia: Universityof Pennsylvania Press, 1960), pp. 229-34; R. Carneiro,"Slash-and-Burn Cultivation Among the Kuikuru and itsImplications for Cultural Development in the AmazonBasin," in J. Wilbert, ed., The Evolution of HorticulturalSystems in Native South America: A Symposium (Cara-cas: Sociedade de Ciencias Naturales La Salle, 1961), No.2, pp. 47-67.53 C. Nimuendaju, The Apinaye (Washington: CatholicUniversity of America Press, 1939), p. 6.54 W. Denevan, "A Cultural-Ecological View of theFormer Aboriginal Settlement in the Amazon Basin,"Professional Geographer, Vol. 18 (1966) pp. 346-51; R.Carneiro, "Transition from Hunting to Horticulture in theAmazon Basin," Proceedings of the 8th Congress of An-thropological and Ethnological Sciences (Tokyo andKyoto, 1970), Vol. 3, pp. 244-48; W. Denevan, "CampaSubsisitence in the Gran Pajonal, Eastern Peru," Geo-graphical Review, Vol. 61 (1971), No. 4, pp. 496-518; J.game mammals are reduced within a few yearsaround peasant communities in the Amazonbasin.55 But hunger for mammal meat shouldnot be confused with a protein shortage; manytribes consume large quantities of insectswhich are an excellent source of aminoacids.56 Vegetable sources of protein alsomake an important contribution to the nativediet, including fungi, beans, nuts, palm fruits,and palm hearts.57By conducting extended hunting trips of upto several months, some groups, such as theKayap6 of the middle and upper Xingu andthe Xikrin of the Itacaiunas River, spreadhunting pressure over a wide area.58 TheSiskind, To Hunt in the Morning (London: Oxford Uni-versity Press, 1973); D. Gross, "Protein Capture and Cul-tural Development in the Amazon Basin," American An-thropologist, Vol. 77 (1975), pp. 526-49; and E. Ross,"Food Taboos, Diet, and Hunting Strategy: The Adap-tation to Animals in Amazon Cultural Ecology," CurrentAnthropology, Vol. 19 (1978), No. 1, pp. 1-36.55 N. Smith, "Utilization of Game Along BrazilsTransamazon Highway," Acta Amazonica, Vol. 6 (1976),No. 4, pp. 455-66; and N. Smith, "Human Exploitationof Terra Firme Fauna in Amazonia," Ciencia e Cultura,Vol. 30 (1978), No. 1, pp. 17-23.56 J. Carvalho, "Relagoes Entre os Indios do Alto Xin-gu e a Fauna Regional," Publica(&es Avulsas do MuseuNacional Vol. 7 (1951), pp. 3-16; K. Oberg, "IndianTribes of Northern Mato Grosso, Brazil," SmithsonianInstitution, Institute of Social Anthropology, Publication,No. 15 (1953), 1-144; P. Bruzzi Alves da Silva, A Civili-zagdo Indigena do Uaupes (Sdo Paulo: Linogrdfica Edi-t6ra, 1962), p. 220; N. Chagnon, Yanomamo: The FiercePeople (New York: Holt, Rinehart and Winston, 1968),p. 30; H. Baldus, Tapirap&:Tribo Tupi no Brasil Central(Sdo Paulo: Companhia Editora Nacional, 1970), p. 165;Harner, op. cit., footnote 18, p. 62; G. Reichel-Dolmatoff,Amazonian Cosmos: The Sexual and Religious Symbol-ism of the Tukano Indians (Chicago: University of Chi-cago Press, 1974), p. 62; K. Taylor, Sanumd Fauna: Pro-hibitions and Classifications (Caracas: Fundaci6n LaSalle de Ciencias Naturales, 1974), p. 23; Smole, op. cit.,footnote 18, p. 163; B. Platt, "Tables of RepresentativeValues of Foods Commonly Used in Tropical Countries,"Medical Research Council, London, Special Report Se-ries, No. 302 (1962), pp. 1-46; and "Amino-Acid Contentof Foods," Food and Agricultural Organization, Nutri-tional Studies, No. 24 (1970), pp. 1-285.57 G. Prance, "The Mycological Diet of the YanomamIndians," Mycologia, Vol. 65 (1973), No. 1, pp. 248-50;0. Fidalgo and G. Prance, "Ethnomycology of the San-ama Indians," Mycologia, Vol. 68 (1976), No. 1, pp. 201-10; S. Beckerman, "The Abundance of Protein in Ama-zonia: A Reply to Gross," American Anthropologist,Vol. 81 (1979), pp. 533-60.58 S. Dreyfus, Les Kayapo du Nord, Etat de Pard-Bre-sil: Contribution a lEtude des Indiens Ge (Paris: Mouton,1963); D. Werner, "Trekking in the Amazon Forest,"Natural History, Vol. 87 (1978), No. 9, pp. 42-55; and R.
566 NIGEL J. H. SMITH Decembersmoked and sun-dried meat and collected tor-toises provide protein when local hunts areunproductive. The protein problem of the Am-azonian interfluves has been exaggerated; anadult requires 0.77 g protein a day per kg ofbody weight if the amino acids are derivedfrom vegetable and animal sources.59 A 65 kgadult need only consume 37 g of meat, or 60g of meat and vegetable protein, to satisfy hisdaily amino acid requirements.The small and often seminomadic habits ofgroups that live in interfluve areas of Ama-zonia are not a vignette of the past. Mosttribes have been drastically reduced, or havedied out, since contact. During the first half ofthis century, at least eighty-seven tribes havebecome extinct in Brazil, mostly in the Ama-zon region. Introduced diseases have oftendevastated immunologically virgin groups.60Violent conflicts with rubber tappers, cathunters, settlers, and cattle ranchers have alsochecked the establishment of large, sedentaryaboriginal populations.61Other cultural factors operate to keep somegroups small, such as fissioning because of in-tratribal disputes.6 A group may abandon avillage site because of superstition and fear ofthe deceased.63Caron, Cure dIndiens (Paris: Union Gen6rale dEditions,1971), p. 278.59 "Energy and Protein Requirements," World HealthOrganization, Technical Report Series, No. 522, pp. 1-118.60 D. Ribeiro, "Indigenous Cultures and Languages ofBrazil," in J. Hopper, ed., Indians of Brazil in the 20thCentury (Washington: Institute for Cross Cultural Re-search, 1967), p. 238; J. Neel, "Lessons from a Primi-tive People," Science, Vol. 170 (1970), pp. 815-22; E.Arnaud and A. Alves, "A Extingdo dos Indios Karara6(Kayap6), Baixo Xingu, Pard," Boletim do Museu Goel-di, Antropologia, No. 53 (1974), pp. 1-19; and E. Arnaud,"Os Indios Gavides de Oeste: Pacificagdo e Integragdo,"Publicaq6es Avulsas do Museu,Goeldi, No. 28 (1975), pp.1-86.61 S. Davis, Victims of the Miracle: Development andthe Indians of Brazil (Cambridge: Cambridge UniversityPress, 1977).62 p. Lima, "Os Indios Waur," Boletim do MuseuNacional, N.S., Antropologia, No. 9 (1950), pp. 1-25; I.Goldman, The Cubeo: Indians of the Northwest Amazon(Urbana: University of Illinois Press, 1966);and N. Chag-non, "Fission in an Amazonian Tribe," The Sciences,Vol. 16 (1976), No. 1, pp. 14-18.63E. Galvdo, "Cultura e Sistema de Parentesco dasCONCLUSIONSNumerous terra preta sites in the Amazonbasin provide strong evidence that precontactnative populations were in many cases largeand sedentary, particularly along rivers. Un-like other areas of Latin America, there areno careful colonial records on aboriginal pop-ulations for Amazonia. Nevertheless, basedon missionary reports, accounts of early trav-elers, and estimates of the carrying capacity ofvarious environments, Denevan suggests thatthere may have been as many as 6.8 millionIndians living in the region toward the closeof the fifteenth century.64Denevans figure is much higher than hashitherto been proposed. Wagley allows only1 million for the Amazon basin in 1500.65Buteven Denevans figure is surely too low; it rep-resents an average of only 1 person per sq.km. There is no ecological reason why the car-rying capacity could not be much higher. Thedisappointing results of the efforts to colonizethe interfluves of Amazonia along pioneerroads should not be blamed on the biophysicalenvironment. Settlement problems are duemore to cultural, rather than ecological, limi-tations .66Biologists should be wary when they dis-cuss virgin Amazonian ecosystems. Potsherdsand black earth may lurk under control plotsand pristine nature reserves. What appears tobe untouched wilderness could have been agarden plot, or a bustling village, hundreds orthousands of years ago. The savannas of Ro-raima and the grasslands of Marajo Island aredue partly to man-made fires. Open campinascrub on sandy soils was once cleared by In-dians.67More cultural surprises await beneaththe forest mask.Tribos do Alto Rio Xingu," Boletim do Museu Nacional,Antropologia, Vol. 14 (1953), pp. 1-56.64 W. Denevan, "The Aboriginal Population of Ama-zonia," in W. Denevan, ed., The Natihe Population ofthe Americas in 1492 (Madison: University of WisconsinPress, 1976), pp. 205-34.";5 Wagley, op. cit., footnote 28, p. 272.66 N. Smith, "Agricultural Productivity Along BrazilsTransamazon Highway, Agro-Ecosystems, Vol. 4(1978), pp. 415-32.67Prance and Schubart, op. cit., footnote 10.