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 18:43

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ANTHROSOLS AND HUMAN CARRYING CAPACITY IN AMAZONIA*

NIGEL J. H. SMITH

ABSTRACT. The occurrence of numerous areas of black soil associated with potsherds in Amazonia has stirred controversy on the origins of the soil type and its 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 is anthropogenic. An analysis of the physical and chemical properties of the soil type, based on widespread sampling, supports the anthropogenic argument. The abundance and depth of black earth sites indicates that Indian populations were dense and in many cases sedentary before the arrival of Europeans, even in interfluve areas.

THE current low population density of Amazonia, with only I inhabitant per sq.

km, has long puzzled geographers, anthropol- ogists, sociologists, and economists. Why does such a huge area, roughly 7 million sq. km, which contains one of the world's richest biomes, contain so few people? According to one viewpoint, the rain forest is not conducive to the development of higher cultures.1 The meager protein sources and the generally poor soils 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, DC 20036.

* Soil samples were collected under grants from the Center for Latin American Studies, Berkeley, a Dean's Fellowship, University of California, Berkeley, and from INPA, Manaus. I am grateful to Italo Falesi for arranging to have the soil samples analyzed at the EMBRAPA and IDESP laboratories in Bel6m, Brazil. I would like to thank the Ford Foundation for providing me with a travel grant to conduct library research for the paper at Berkeley. I am also grateful to David Arkcoll, Woodrow Borah, Su- sanna Hecht, and an anonymous reviewer for their helpful comments 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 Potential and the Development of Cultures," Southwestern Journal of 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 has been generally accepted. A mosaic of black earth patches, scattered throughout the Am- azon basin, provides evidence that precontact native populations were in many cases large and sedentary. Black earth, ceramic material, and stone tools are the only vestiges of ancient civilizations in Amazonia; the remainder, ex- cept for artificial mounds, has perished under the hot and humid conditions. To examine the case for the anthropogenic origin of black earth, theories on its genesis are examined, the physical and chemical properties of the soil type are analyzed, and the site character- istics are described. Finally, the controversy on the scarcity of subsistence resources in the region is explored.

THEORIES ON THE ORIGIN OF

BLACK EARTH

In the Brazilian Amazon, black earth with potsherds is referred to as terra preta do indio (Indian black earth) and is recognized as a soil type.2 Terra preta is an anthrosol, character- ized by a distinctive anthropogenic epipedon.3 Intermixed potsherds and celts are a major distinguishing feature of the soil. Dark soils rarely occur without the influence of man in

2 I. Falesi, "Soils of the Brazilian Amazon," in C. Wag- ley, ed., Man in the Amazon (Gainesville: University of Florida 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 December

Amazonia; alluvial soils rich in organic matter are an exception. But Indian black earth is found on a variety of soil types and geomor- phological surfaces, and retains its sooty color even under intense leaching.

Fallout from volcanoes in the Andes has been suggested as the origin of black earth lo- calities on the Belterra plateau south of San- tarem.4 Black earth sites supposedly are only found on the highest portions of the plateau that would have trapped ash in a manner sim- ilar to snowdrifts. The decrease in the levels of phosphorus and calcium down the black earth profiles is cited as further evidence that they are due to volcanic precipitation in the late Tertiary or early Quaternary. Aborigines subsequently occupied the sites leaving bro- ken pieces of pottery and stone tools as ves- tiges.

Several problems arise with the volcanic ash theory. First, prevailing winds in Ama- zonia blow from east to west, thus rendering unlikely the aerial transport of debris several thousand km from the west. Even if the pre- vailing winds were reversed in the past, one would expect a reasonably even distribution of ash over large areas, similar to loess soils, rather than in irregular patches. Second, the theory does not explain why potsherds are en- countered throughout the profile since plough- ing in Amazonia is extremely rare and was almost 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 earth profiles. Third, it is normal for calcium and phosphorus salts to diminish down the profile in most soils since the litter decomposes, and nutrients are generally recycled, close to the surface.

Sedimentation in lakes has been proposed as another origin of terra preta do indio.5 Ac- cording to this theory, black earth patches formed when a large Tertiary lake, formed by the rising Andes, eventually broke through the granitic shield in the east and flowed, as the Amazon River, to the Atlantic. As the vast lake drained, ponds appeared on the uneven bed and these depressions slowly filled in with plants 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.

mat bones in the eutrophication process would account for the generally high phosphorus content of black earth.

It is not certain, however, that a lake formed when the Andes emerged at the begin- ning of the Tertiary.6 Tertiary sediments, ex- tending down several thousand meters in some areas, may have resulted from alluvial or colluvial fill.7 Another problem with the theory is that terra preta sites are also found in areas that would not have been covered by the lake in the western half of Amazonia, such as the Pre-Cambrian Brazilian shield and Si- lurian diabase dikes. Furthermore, Indian black earth is found on Quaternary alluvium.

Another version of the pond theory con- tends that the terra preta sites on the Belterra plateau were formed in recent times. Small depressions would fill with water in the rainy season and erosion of litter from surrounding vegetation, as well as organic matter from aquatic plants, would eventually fill in the ponds and produce a rich, dark soil. Mean- while, Indians would use the ponds to soften manioc tubers before making flour. Discarded platters, once used on the ovens to toast the flour, would account for sherds in the soil.8

A major problem with the recent pond the- ory is that black earth sites also occur in areas where water is unlikely to collect, such as on high banks overlooking rivers, or on tops of hills. Furthermore, it seems unlikely that ab- origines would toss garbage and broken pot- tery into ponds, thereby polluting their water supply.

The impressive number of terra preta sites along the Trombetas and Jamundac rivers has led one author to speculate that they must have resulted from the filling in of floodplain lakes.9 This theory does not explain how black earth sites are formed on terra firme.

6 The geomorphological history of Amazonia is poorly understood. See, for example, N. Ab'Saber, "Problemas Geomorfol6gos 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 Clima Tropical," Atas do Simp6sio s6bre a Biota Amaz6nica, Vol. 1 (1967), pp. 327-37.

" E. Cunha Franco, "As Terras Pretas do Planalto de Santar6m," Revista da Sociedade dos Agronomos e Ve- terina'rios do Parid, Vol. 8 (1962), pp. 17-21.

9 J. Faria, A Ceramica da Tribo Uaboi dos Rios Trom- betas e Jamundd (Rio de Janeiro: Imprensa Nacional, 1946).

1980 ANTHROSOLS AND CARRYING CAPACITY 555

The 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 garden plots, presumably as a result of burning slash.10 This explanation does not account for the depth of dark soil, up to 2 m in some cases, since burning forest or second growth would deposit only a thin layer of ash on the soil. In the swidden system, the predominant farming pattern of natives in Amazonia, a plot is burned 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 was formed in Indian fields due to the incorpora- tion of bones and organic matter.'1 But there is no evidence that natives applied organic fer- tilizers to their fields in Amazonia; it is not practiced today. None of the theories so far adequately account for the presence of sherds in terra preta (Fig. 1).

Black earth localities are usually considered to be a cultural layer accumulated at former Indian villages.'2 Terra preta is attributed to

10 G. Prance and H. Schubart, "Nota Preliminar sobre a 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 on the Vegetation of Amazonia I. A Preliminary Note on the Origin of the Open White Sand Campinas of the Lower Rio Negro," Brittonia, Vol. 30 (1978), No. 1, pp. 60-63.

11 Bennema, 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 Middle Xingi River," in J. Steward, ed., Handbook of South American Indians (Washington: Smithsonian Institution, 1948), pp. 213-43; P. Gourou, "Observag6es Geogrdficas na 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 as Applied to a Problem of Amazon Morphology," Comptes Rendus du XVIII Congres International de Geographie, Vol. 2 (1960), pp. 399-424; H. Klinge, "Beitrdge zur Kenntnis Tropishcer Boden V. Uber Gesamtkohlenstoff und 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 Te'cnico, 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 and Documentation, 1966); and B. Meggers and C. Evans, "An Interpretation of the Culture of Maraj6 Island," in

,W, ArpU- i0: 8

poshrd, Itcair, mzns

of refuse. Objections to the anthropogenic or-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~. ...........

FIGin ofAtrooe black earth hae fee rIsedt onithe

grounds that there is insufficient water on the Belterra plateau to support year-round human occupation. 13 Although streams are virtually absent on the plateau, the now extinct TapaJ6 tribe dug wells for water, some of which are still in use by peasants.'14 Black earth is still being formed today; a darkening of the soil can 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.'15 But the rate of black earth formation is prob-

D. Gross, ed., Peoples and Cultures of Native South America (New York: Natural History Press, 1973), pp. 39-47.

13 Cunha Franco, op. cit., footnote 8. 14 C. Nimuendaju, "Os Tapaj6," Boletim do Museu

Goeldi, 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 December

TABLE 1.-ANALYSIS OF ANTHROPOGENIC BLACK EARTH IN THE BRAZILIAN AMAZONa

Texture % % Exchangeable bases mE/100 g Cation Base % Nitro- mg/100 g exchange satura- H20

Site Sand Silt Clay Carbon gen P205 Ca Mg K Sum Al capacity tion pH

1 77 18 5 1.77 0.14 10.99 - - 0.60 10.02 0.00 10.02 100 7.9 2 52 27 21 1.41 0.11 0.54 3.00 1.90 0.30 5.22 0.40 10.50 50 4.9 3 55 22 23 1.84 0.14 16.90 4.60 1.20 0.04 5.87 0.40 10.65 55 5.3 4 68 21 11 1.73 0.08 89.00 6.20 0.59 0.23 7.06 0.10 12.01 59 5.6 5 72 17 11 1.26 0.09 0.49 3.85 0.61 0.05 4.54 0.20 10.31 44 5.4 6 71 16 13 2.06 0.18 1.17 4.14 0.78 0.09 5.04 0.00 12.79 39 5.5 7 81 17 2 0.87 0.05 0.52 0.19 0.02 0.01 0.23 1.60 7.16 3 4.2 8 40 35 25 1.65 0.16 119.60 6.80 0.60 0.10 7.54 0.00 13.31 57 5.3 9 8 44 48 3.50 0.46 33.00 10.00 1.94 0.12 12.09 0.00 18.69 65 5.6

10 10 55 35 2.50 0.32 35.00 10.00 2.91 0.42 13.40 0.00 19.17 70 5.6 11 66 11 23 1.14 0.12 0.60 0.72 0.28 0.05 1.07 1.04 9.31 11 4.6 12 37 38 25 2.13 0.23 14.55 10.08 1.04 0.56 11.71 0.14 15.29 77 6.2 13 86 3 11 0.45 0.06 15.30 0.80 0.48 0.05 1.36 0.85 6.02 23 4.6 14 66 10 24 0.71 0.08 139.20 5.20 0.48 0.16 5.89 0.15 9.83 60 6.1 15 22 30 48 3.11 0.31 154.80 15.28 2.88 0.11 18.35 0.18 23.90 77 5.9 16 66 13 21 0.81 0.20 14.65 4.56 0.48 0.16 5.21 0.05 5.88 89 7.0 17 38 38 24 2.71 0.26 48.00 11.92 0.72 0.45 13.10 0.07 18.13 72 5.9 18 83 5 12 1.11 0.07 2.80 0.22 0.99 0.01 1.23 0.99 7.11 17 4.6 19 65 19 16 2.70 0.18 30.00 1.21 0.55 0.06 1.84 0.79 10.83 17 4.6 20 96 3 1 0.76 0.05 0.26 0.11 0.33 0.01 0.46 0.69 3.81 12 4.3 21 86 4 10 0.67 0.07 7.76 0.22 0.77 0.03 1.03 1.19 4.46 23 4.6 22 80 5 15 1.25 0.09 0.32 0.22 0.50 0.07 0.81 0.99 5.47 15 4.6 23 19 36 45 4.70 0.34 30.00 10.20 2.77 0.21 13.21 0.10 19.09 69 5.7 24 86 7 7 2.09 0.12 1.13 1.83 0.37 0.03 2.25 0.30 9.20 24 5.4 25 72 8 20 1.12 0.08 37.60 2.51 1.15 0.04 3.72 0.30 9.28 40 5.4 26 55 22 23 1.91 0.16 32.60 5.23 0.63 0.06 5.95 0.10 11.43 52 5.3 27 68 14 18 1.48 0.10 315.00 7.18 0.31 0.07 7.68 0.19 11.58 66 5.5 28 69 20 11 1.30 0.08 0.41 1.67 0.42 0.08 2.21 0.74 8.32 27 4.5 29 74 10 16 1.50 0.11 10.90 3.64 0.93 0.11 4.71 0.16 8.61 55 5.5

a 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, and most fires are built above ground.

PHYSICAL AND CHEMICAL PROPERTIES OF

ANTHROPOGENIC BLACK EARTH

The dark color of terra preta is the most striking feature of the soil; it stands out among the predominant yellow and red soils of the basin. Unlike in temperate areas, peaty soils are very rare in Amazonia. The color ranges from jet 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 was inhabited. The stability of the dark color, even after prolonged exposure to the hot sun and torrential rains, is remarkable. The inky color is most likely due to a complex formation of organic matter and calcium ions that form a coating 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, are probably binding carbon to soil colloids.

The dark color is due largely to residue from fires. Many Indian villages have a cleared space, usually in the middle, which is kept clean 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 the soil to be built up around the village in donut fashion. 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 former occupants heaped earth to escape the water- logged conditions during the rainy season. The deepest portion of Indian black earth sites that I have seen is in the middle, gradually becom-

17 T. Myers, "Toward Reconstruction of Prehistoric Community 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 557

1600 W 1500 w

00 T UARA

FIG.S 2.Loaiosofalakeat ste amld nth Ara nA mo

TACOATIARA ~ ~ MRAB

*TOWNS

HIGHWAYS * ANTHROPOGENIC BLACK EARTH SITE

0 500 km

FIG. 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 burning at all times to cook and keep warm, as well as to ward off evil spirits at night.18 Over de- cades, and in some cases probably centuries or millennia, incomplete combustion around low-heat fires would produce carbon-rich hearths. The carbon content of twenty-nine

18 A. 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 Their Neighbors," in J. Steward, ed., Handbook of South American 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, The Yanoama 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).19

Black earth sites occur on a variety of soil types, including latosols (oxisols), podzolic soils (ultisols), terra roxa eutr6fica (eutrophic oxisols) and podzols (spodosols) (Table 2).2? It thus seems unlikely that terra preta would result from natural soil forming processes. The texture of sampled black earth ranges from 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 human occupation of the site. The exposed condition

19 Only black earth with potsherds was sampled. At each site a composite sample was gathered from fifteen randomly selected sublocations and then mixed. Black earth was sampled to a depth of 20 cm. For characteristics of each site, see Table 2.

20 Bennema, op. cit., footnote 3, states that Indian black earth occurs on kaolinitic yellow latosols but does not mention that it is also found in other soil types.

TABLE 2.-LOCATION AND CHARACTERISTICS OF SAMPLED ANTHROPOGENIC BLACK EARTH SITES

Black ?? Black earth earth max. Surrounding

Site Location Vegetation area ha depth m soil type Observations

I Gleba 24, lot 20, km 77 Arara Indian field 4 1.5 0.40 Terra roxa Sherds abundant on surface and Altamira-Itaituba, yrs old to depth of 15 cm. Site Transamazon, Pard. roughly circular in shape. Perennial stream 300 m away.

2 Gleba 34, lot 17, km 105 Colonist field in 5.0 0.20 Red- Sherds found between 10-20 cm Altamira-Itaituba, coffee, 1 yr old, yellow depth, stone axe found. Site Transamazon, Para. cleared from latosol roughly circular in shape. Perennial stream 300 m mature forest away.

3 Agropolis Miritituba, right Open area in weeds, 10.0 0.20 Yellow Sherds and stone axes numerous bank of Tapaj6s River, cleared from latosol on surface and to depth of 20 Pard. secondary forest cm. Site stretches I km along

bank and 100 m inland. z

4 Itupiranga, left bank of Open area in grass 4.0 0.70 Red- Sherds and celts on surface and Tocantins River, Pard. and mango trees yellow to depth of 50 cm.

podzolic

5 Gleba 24, lot 26, sideroad km Open area by 1.0 0.40 Yellow Sherds on surface and to depth 80 Altamira-Itaituba, COBAL store, latosol of 10 cm. Site roughly circular Transamazon, Pard. cleared from forest in shape. Perennial stream 400 m 2 yrs ago away.

6 Gleba 31, lot 12, sideroad km Mature forest 0.5 0.87 Terra roxa Sherds at 15 cm depth. Site 100 Altamira-Itaituba roughly circular in shape. Transamazon, Pard. Perennial stream 200 m away.

7 Km 139 Itacoatiara-Manaus, Campina 0.5 0.20 Podzol Sherds frequent on surface and Amazonas. Perennial to depth of 20 cm. Site stream 300 m away. lenticular in shape.

8 Atlantic veneer mill, Open weedy area 30.0 1.00 Yellow Sherds abundant and celts Itacoatiara, left bank of latosol frequent on surface and to Amazon River, Amazonas. depth of 10 cm. Site extends 1

km along bank and 300 m inland.

9 Lago de Terra Preta, 30 km Maize and squash 0.8 0.45 Red Sherds on surface and to 10 cm C

S.E. of Itacoatiara, field 2 yrs old. latosol depth. Site extends 100 m C

Amazonas. Bluff Cleared from 2nd along margin of lake and 80 m C overlooking blackwater growth inland. lake.

TABLE 2.-CONTINUED.

Black Black earth earth max. Surrounding

Site Location Vegetation area ha depth m soil type Observations

10 Entrance to Lago de Batista, Cacao grove some 40 0.4 0.4 Yellow Sherds at 10 cm depth. Site

25 km S.E. of Itacoatiara, yrs old latosol extends 50 m along margin of

Amazonas. Bluff lake and 80 m inland.

overlooking blackwater lake.

11 Km 2 Aripuana-Colonia dos Mature forest 0.5 0.20 Latosol Sherds and celts to 20 cm depth. Patos, northern Mato Site roughly circular in shape.

Grosso. Perennial stream 500 m away.

12 Aripuana, right bank of Open, town streets 24.0 0.50 Yellow Sherds and celts frequent to 50 >

Aripuana River, northern and square latosol cm depth. Site lenticular in Z

Mato Grosso. shape.

13 Lago de Madruba, 6 km Open grassland 0.5 0.50 Podzol Sherds numerous to 50 cm 0

north of Itapiranga, Am. depth. Site extends for 100 m

Margin of blackwater lake. along margin of lake and 50 m inland.

z 14 Itapiranga, left bank of Open backyard 8.0 1.00 Yellow Sherds abundant on surface and

Parand Silves, Amazonas. latosol to depth of 50 cm. Site extends 800 m along bank and > 100 m inland.

15 Terra Nova, Parand do I yr 2nd growth 45.0 0.90 Yellow Sherds common on surface and

Silves, 1 km west of latosol to 50 cm depth. Site extends Z

Itapiranga, Amazonas. for 1.5 km along bank and 300 m inland.

16 Gleba 24, lot 8, km 74 Manioc field 0.3 0.15 Podzol Sherds abundant on surface and

Altamira-Itaituba, to 15 cm depth. Site lenticular

Transamazon, Pard. in shape. Perennial stream 30 m away.

17 Missdo, left bank of Xingu Open area with weeds 90.0 0.68 Yellow Sherds and celts abundant on

River, 1.8 km south of latosol surface and to 10 cm depth. Altamira, Pard. Site extends 1.8 km along

bank and 500 m inland.

18 Praia Dourada, Tarumd Open grassland with 3.2 1.47 Yellow Sherds abundant to 1.4 m depth. River, 15 km N.W. of weeds podzolic Celts. Site extends 188 m

Manaus, Am. Blackwater along river and 170 m inland.

River.

19 Tapurucuara, Rio Negro, Open grassland 7.0 1.09 Red- Sherds common on surface and

Amazonas. yellow to depth of 85 cm. Celts. Site podzolic extends 700 m along bank and

100 m inland.

TABLE 2.-CONTINUED.

Black Black earth earth max. Surrounding

Site Location Vegetation area ha depth m soil type Observations

20 Campina, estrada de Terra Campina 1.0 0.24 Podzol Sherds on surface to 10 cm Preta, sideroad at km 4 depth. Site lenticular. Cacau Pirera-Manacapuru, Am. Margin of perennial stream.

21 Km 4 Cacau Pirera- Early 2nd growth 4.0 0.84 Red- Sherds abundant on surface and Manacapuru, Am. Margin yellow to 70 cm depth. Celts. Site of perennial stream. podzolic lenticular.

22 Estrada de Terra Preta, Campinarana forest 0.5 0.20 Podzolic Sherds infrequent from surface sideroad at km 4 Cacau to 20 cm depth. Site lenticular. Pirera-Manacapuru, Am. Perennial stream 200 m away.

23 Ponta das Lajes, Rio Negro, 2nd growth of several 6.0 0.25 Yellow Sherds abundant from surface to z Manaus, Amazonas. years latosol 25 cm depth. Site extends 550

m along bank and I10 m inland.

24 Km 8 Ponta Negra road, Campinarana 35.1 1.41 Podzol Sherds infrequent on surface and Manaus, Amazonas. to 5 cm depth. Site extends

2.7 km along bluff and 130 m inland.

25 Ceramica Irco, km 15 Aleixo Grassland 0.8 0.50 Yellow Sherds abundant to 30 cm depth. road, Manaus, Am. Bluff podzolic Site extends 130 m along bluff overlooking Amazon. and 60 m inland.

26 Manacapuru, Amazon River, 2nd growth of several 80.0 1.00 Yellow Sherds abundant from 5-90 cm Amazonas. years latosol depth. Site extends 4 km along

bank and 200 m inland.

27 Itaituba, Tapaj6s River, Pard. Open, bare ground 15.0 0.45 Yellow Sherds rare from surface to 15 latosol cm depth. Site extends 1 km

along bank and 150 m inland.

28 Gleba 12, lot 7, km 30 Backyard weeds, 0.7 0.35 Podzolic Sherds numerous from surface to Altamira-Maraba, cleared from forest 10 cm depth. Site lenticular. Transamazon, Pa. Margin 8 yrs ago of perennial stream.

29 Km 30 Itaituba-Altamira, Open, bulldozed 1.6 0.25 Latosol Sherds numerous from surface to junction of Transamazon 15 cm depth. Site lenticular. and Cuiabd-Santarem highways, Pa. Perennial stream 200 m away.

1980 ANTHROSOLS AND CARRYING CAPACITY 561

of a village promotes the mechanical eluvia- tion of clay to lower horizons. In test plots of non-terra preta soils along the Transamazon highway, the top 5 centimeters became slight- ly, but significantly, sandier within three years of exposure.21 The fact that black earth sites are found on podzols is at variance with the idea that they were formed as a result of ag- ricultural activities. Sandy soils in Amazonia are especially poor in nutrients. Still, a podzol would provide a convenient habitation site if there were suitable agricultural soils in the vi- cinity since it would be much less muddy in the 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 poor in nutrients because of prolonged leaching and because the weathering front of the geological substrate is too deep to provide nutrients for plants. Fires would liberate nutrients into the soil and the break down of kitchen middens would 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 source in black earth sites of Amazonia.22 Adult In- dians generally retire into the bush or forest to eliminate metabolic wastes; small children would contribute a few nutrients to the soil by defecating and urinating promiscuously within the village.

Phosphorus, in particular, is considered one of the most significant elements indicating former human occupation of a site.23 Phos- phates are often in short supply in Amazonian soils. Whereas in oxisols and ultisols, which ac- count for the majority of Amazonian soils, the available phosphorus content is usually under 5 mg/100 g, in the sampled Indian black earths

21 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 to the Relation of the Physical Components to the Probable Material Culture," University of California Publications in 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 in one case it reached 315 mg/100 g (Table 1). The lowest quantities of phosphorus in the sampled terra preta are found in the sandier soils; leaching and phosphorus fixation in the form of iron and aluminum phosphates prob- ably are responsible. It seems likely that sites abandoned long ago also would lose phos- phorus.

In an analysis of Indian black earth from five sites, Sombroek found phosphorus levels ranging from 6.9 to 99 mg/100 g, also from 0 to 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 depth of 30 centimeters,25 24.0 mg/100 g to a depth of 8 centimeters,26 and 1.4 and 11.7 mg/100 g in two black earths sampled to a depth of 10 centimeters.27 Ash from fires, bones from fish and game animals, feces, urine, and turtle shells account for the relatively high levels of phosphorus in black earth. In some cases, hu- man bones may also have contributed to the phosphorus 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 their village.28

Calcium levels in sampled anthropogenic epipedons are also generally high, averaging 4.7 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, ranging up to 25 mg/100 g of soil.29 Animal and human bones would account for some of the concen- tration of the element at black earth sites. Be- cause calcium levels are generally high, base saturation is usually moderate to high, aver- aging 47.2% (s = 25.9). The pH of sampled

24 Sombroek, 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 Solos da 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. 28 C. Wagley, Welcome of Tears: The Tapirape Indians

of 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.

29 Sombroek, op. cit., footnote 12, p. 253.

562 NIGEL J. H. SMITH December

black earth sites averaged 5.4 (s = 0.8), whereas the pH of oxisols and ultisols in Amazonia is usually under 5. Below pH 5.5, the activity of soil bacteria and actinomycetes, as well as the availability of nutrients such as nitrogen, calcium, magnesium, potash, phos- phorus, and sulphur, are sharply reduced.30 Aluminum levels of the sampled black earth sites generally were moderate to low, aver- aging 0.4 mg/100 g (s = 0.4). Levels in excess of 1.0 mg/100 g are not uncommon in oxisols and ultisols in Amazonia, and can be toxic to crop plants.

UTILIZATION OF ANTHROPOGENIC

BLACK EARTH

The superior fertility of Indian black earth is widely appreciated throughout Amazonia.31 Aboriginal groups, such as the Mundurucii of the upper Tapaj6s River and the Xikrin of the Itacaiunas River, recognize the soil as espe- cially valuable for agriculture.32 The Maw6 In- dians favor anthropogenic epipedon to grow guarand vines (Paullinia cupana), the fruits of which are roasted and prepared into a refresh- ing regional drink.33

On the Belterra plateau the numerous black earth sites are sought out by civilized Indians and peasants for farming, though in some cases the abundant sherds create a nuisance.34 Peasants favor anthropogenic black earth for their garden plots along the Trombetas and Jamundai rivers.35 Terra preta do indio is re- puted to be particularly good for growing fruit trees, cacao, bananas, and vegetables.36 Some

30 N. Brady, The Nature and Properties of Soils (New York: 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 Avulsas do Museu Goeldi, Vol. 7 (1968), pp. 3-119.

33 N. Pereira, Panorama da Alimentaqiio Indigena: Comidas, Bebidas e T6xicos na Amaz6nia Brasileira (Rio de Janeiro: Livraria Sao Jose, 1974), p. 31.

34 C. Hartt, "Contribui96es para a Ethnologia do Valle do 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 do Pard, 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.37 Som- broek asserts, however, that the trees are more resistant to the highly-destructive fungal leaf blight (Microcyclus ulei) on the soil.38

Anthropogenic black earth is in brisk de- mand in urban areas for spreading on yards to promote the growth of grass, ornamental plants, and vegetables. In Manaus, black earth is trucked from sites along the Amazon River as far as 40 km away and is sold for U.S. $100 per 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 preta from waste lots within town and distributed to upper class homes. Because of the widely ac- claimed agricultural value of Indian black earth, and the favorable location of the sites, many of the sites have been heavily disturbed, rendering archeological studies difficult.

CHARACTERISTICS OF ANTHROPOGENIC

BLACK EARTH SITES

Most known Indian black earth sites are along rivers. In the case of silt-laden water courses, a fertile floodplain provides bountiful harvests and plenty of fish, turtles, and, for- merly, manatees for protein. Early expedi- tions into the Amazon basin, such as that of Orellana in 1542, traveled along major rivers and often encountered dense native popula- tions.39 But surprisingly, twelve of the twenty- nine sampled black earth sites are in upland areas.

Since terra preta with sherds is of anthro- pogenic origin, one would expect the sites to be advantageous for human settlement. A no- table feature of the sampled black earth sites is that they are either on the bank of a peren- nial water course, or within a few hundred meters of one (Table 2). Along rivers, black earth sites are often found just above falls, such as Vila Aripuand by Cachoeira dos An- dorinhos on the Aripuand River or just above

37 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 According

to the Account of Friar Gaspar de Carvajal and Other Documents (New York: American Geographical Society, 1934).

1980 ANTHROSOLS AND CARRYING CAPACITY 563

rapids, such as at Altamira on the Xingu (Fig. 2). Along the Rio Negro, black earth almost invariably occurs wherever a slab of granitic rock juts into the water. Such sites would pro- vide convenient work benches for grinding foodstuffs and stone tools. The ready avail- ability of potable water, then, is one of the most important characteristics of terra preta sites.

Many black earth sites are occupied by neo- Brazilian communities. The advantages of the sites persist. According to the Mapa da Bacia Ainazonica published on a scale of 1:1,500,000, four communities in the Brazilian Amazon are called Terra Preta.40 Three are in Amazonas state along the Abacaxis, Canuma, and Ari- puana rivers, and one is in Pard state along the 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 most extensive black earth sites so far discovered in Amazonia.

Black earth sites along rivers are usually larger, and more linear in shape, than those encountered in interfluve areas. Site 17, near Altamira on the clearwater Xingu, stretches 1.8 km along the left bank of the river and 500 m inland, thereby covering 90 ha. Site 26 at Manacapuru on the banks of the muddy Am- azon extends 4 km along the margin of the river and 200 m inland. Only recently has the town of 18,000 grown beyond the boundaries of the 80 ha site. The elongated pattern of the sites suggests linear settlement. Since in many cases the black earth extends several hundred meters 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 terra preta sites were all under 6 ha and averaged 1.4 ha (s = 1.5). Upland sites are roughly cir- cular or lenticular in shape. Such sites were occupied by either a large central communal house (mnaloca), or several houses in one or more circles. The shape and area of black earth sites encountered in the Brazilian Am- azon by other investigators are close to the range that I have found (Table 3). Although interfluvial black earth sites are generally small, in some areas they are numerous. Terra preta is estimated to cover some 50,000 ha

40 Published by the Instituto Brasileiro de Geografia e Estatistica, Rio de Janeiro (1971).

TABLE 3.-RANGE OF AREAS OF SOME ANTHROPOGENIC

BLACK EARTH SITES IN THE BRAZILIAN AMAZON

Area (ha) Shape Location

2-12 Circular to Belterra plateaua lenticular

2-4 No description Trombetas and Jamundd rivers')

<3 Circular Belterra plateauc 2-3 Lenticular Belterra plateau'

0.2-0.4 No description Maraj6, Caviana Islandse

0.03-0.07 Circular or oval North central Maraj6 Island'

1-8 No description Trombetas Riverg 80 Linear Manacapuruh

Falesi, 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 rivers alone.4'

Most anthropogenic black earth sites are less than 1.5 m deep, though 2 m has been recorded (Table 4). The seventeen black earth sites sampled in riverine areas are an average 0.73 m (s = 0.38) deep, whereas the twelve sites sampled in interfluvial areas averaged 0.36 m deep (s = 0.25, Table 2). Both terra

firme and floodplain environments, then, were inhabited by sedentary aboriginal groups in precontact times.

DISCUSSION

It is difficult to estimate how large a popu- lation inhabited each black earth locality. Na- tive buildings were, and still are, made from wood and palm fronds that soon disintegrate. Another problem is that aboriginal cultures in the region use different village plans, ranging from a large communal house to a circle of dwellings. The large riverine terra preta sites may have been occupied for various periods by different groups, each time deepening and possibly extending the area of stained earth. But the entire area of even the largest sites may have been settled at one time; the 80 ha

41 F. Katzer, "A Terra Preta," Boletim da Secqdo de Fomento Agricola no Estado do Parid, Vol. 3 (1944), No. 2, pp. 35-38.

564 NIGEL J. H. SMITH December

TABLE 4.-MAXIMUM DEPTHS OF SOME ANTHROPOGENIC

BLACK EARTH SITES IN THE BRAZILIAN AMAZON

Maximum depth (m) Location

2.0 Lower Amazona 1.5 Belterra plateau" 1.5 Oriximina, Parde 1.2 Belterra plateau' 1.0 Maraj6 Islande 1.0 Belterra plateau' 0.6 Trombetas Riverg 0.5 Belterra plateaUh

Katzer, 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 by as many as 18,000 Indians.42

Although upland black earth sites generally are smaller than riverine ones, they neverthe- less could have been occupied by large groups. A native long-house measuring 34 by 24 meters can shelter at least 100 people; Wi- toto malocas that measured 100 by 50 meters sheltered a community of 400.43 Terra preta mounds on Maraj6 Island, once occupied by Indians of the Ananatuba phase, ranged from 0.03 to 0.07 ha and were the sites of communal houses each sheltering from 100 to 150 indi- viduals.44 The interfluvial black earth sites I sampled range from 0.3 to 5 ha. They were once occupied by villages containing from 100 to 2,000 inhabitants.

The depth of black earth is undoubtedly cor- related with the length of time the site was inhabited, but it is not known how fast ths oil was formed. In the case of Maraj6 Island, 1 m depth of terra preta has been assumed to represent approximately 100 years of occu- pation.45 It seems unlikely that black earth would have formed that quickly considering the rapid rates of organic matter decomposi- tion. A rate of 1 centimeter of terra preta per 10 years of settlement is more likely.

42 Myers, 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. Jennings and 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 created every 10 years, then 2 meters of the soil would represent some 2,000 years of settlement. A study of sherds from black earth sites 5 and 6 along the Transamazon highway reveals the presence of at least two, and possibly three, wares at each locality.46 Several different wares at a site does not necessarily mean that the locality was abandoned and occupied by different groups; the wares could be transi- tional, or trade items. If a 2 meter black earth site was not continuously settled, it could have been first occupied tens of thousands of years ago.

The oldest date so far for pottery in the Bra- zilian Amazon is 980 BC ? 200 years, from charcoal associated with Mangueiras phase sherds on Maraj6 Island.47 The earliest ceram- ic date for the Ucayali River in the Peruvian Amazon is 650 BC ? 100 years.48 Some ar- cheological sites along the Ucayali have been occupied as many as eighteen times with an average stay of 100 years. There have been relatively dense settlements along the Ucayali and other rivers of Amazonia for at least 4,000 years.49

In many terra preta sites, sherds do not al- ways extend to the bottom of the profile; it is possible that preagricultural folk once inhab- ited some of the sites. Leaching of carbon might account for some, but not all, of the black earth in the lower profile without ce- ramics. Man has been in South America for at least 22,000 years, and in the Brazilian states of Goias, Pernambuco, Minas Gerais, and Mato Grosso for a minimum of 10,000 years.50

46 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 Evidence on the Antiquity and History of the Ananatuba Phase," American Antiquity, Vol. 34 (1969), pp. 402-10.

48 D. Lathrap, "Aboriginal Occupation and Changes in River Channel on the Central Ucayali, Peru," American Antiquity, 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," Scientific American, Vol. 224 (1971), pp. 36-46; H. Walter, Ar- queologia dai Regido de Lagoa Santa (Minas Gerais): In- dios Pre-Colombianos dos Abrigos Rochedos (Rio de Ja- neiro: Sedegra, 1958); 0. Fonseca, "Parasitismo e Migragdes 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 Oscillation as a Factor in the Prehistory of Amazonia," American Antiquity, Vol. 44 (1979), pp. 252-66.

1980 ANTHROSOLS AND CARRYING CAPACITY 565

Amazonia with its abundant fish, turtles, in- sects, and fruits would have provided a corn- ucopia for early hunters and gatherers. There is no ecological reason why they might not have lived in the region, and built campfires, for as long as they have in Minas Gerais, or any other part of South America.

Objections have been raised that aboriginal populations were too sparse and transitory to have been responsible for terra preta. It is claimed that Indian settlements are unlikely to exceed 200 individuals in upland areas with manioc as a basic staple.5' On the other hand, it has been convincingly argued that a tribe of 2,000 can remain sedentary on terra firtme by cropping the highly productive tubers in a swidden system within a 6.4 km radius of the village.52 The fact that no Indian villages in Amazonia attain such a size now does not mean they did not in the past. In 1824, even after a century of intermittent contact with Luso-Brazilians, and at least one smallpox ep- idemic, three Apinaye villages on the inter- fluve between the Tocantins and Araguaia contained 1,000 individuals each or more. The largest sheltered 1,600.

The alleged shortage of protein sources in the interfluvial forests of Amazonia has been highlighted as a major factor restricting the size and permanence of aboriginal groups. Game is apparently rapidly depleted in the vi- cinity of a village, and the group must move on to a fresh area in order to survive.54 Large

51 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 Closer Look at its Implications for Settlement Patterns," in A. Wallace, ed., Men and Cultures (Philadelphia: University of Pennsylvania Press, 1960), pp. 229-34; R. Carneiro, "Slash-and-Burn Cultivation Among the Kuikuru and its Implications for Cultural Development in the Amazon Basin," in J. Wilbert, ed., The Evolution of Horticultural Systems 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: Catholic University of America Press, 1939), p. 6.

54 W. Denevan, "A Cultural-Ecological View of the Former Aboriginal Settlement in the Amazon Basin," Professional Geographer, Vol. 18 (1966) pp. 346-51; R. Carneiro, "Transition from Hunting to Horticulture in the Amazon Basin," Proceedings of the 8th Congress of An- thropological and Ethnological Sciences (Tokyo and Kyoto, 1970), Vol. 3, pp. 244-48; W. Denevan, "Campa Subsisitence 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 years around peasant communities in the Amazon basin.55 But hunger for mammal meat should not be confused with a protein shortage; many tribes consume large quantities of insects which are an excellent source of amino acids.56 Vegetable sources of protein also make an important contribution to the native diet, including fungi, beans, nuts, palm fruits, and palm hearts.57

By conducting extended hunting trips of up to several months, some groups, such as the Kayap6 of the middle and upper Xingu and the Xikrin of the Itacaiunas River, spread hunting pressure over a wide area.58 The

Siskind, 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," Current Anthropology, Vol. 19 (1978), No. 1, pp. 1-36.

55 N. Smith, "Utilization of Game Along Brazil's Transamazon Highway," Acta Amazonica, Vol. 6 (1976), No. 4, pp. 455-66; and N. Smith, "Human Exploitation of 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 Museu Nacional Vol. 7 (1951), pp. 3-16; K. Oberg, "Indian Tribes of Northern Mato Grosso, Brazil," Smithsonian Institution, 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 Fierce People (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 La Salle de Ciencias Naturales, 1974), p. 23; Smole, op. cit., footnote 18, p. 163; B. Platt, "Tables of Representative Values of Foods Commonly Used in Tropical Countries," Medical Research Council, London, Special Report Se- ries, No. 302 (1962), pp. 1-46; and "Amino-Acid Content of Foods," Food and Agricultural Organization, Nutri- tional Studies, No. 24 (1970), pp. 1-285.

57 G. Prance, "The Mycological Diet of the Yanomam Indians," 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 l'Etude 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 December

smoked and sun-dried meat and collected tor- toises provide protein when local hunts are unproductive. The protein problem of the Am- azonian interfluves has been exaggerated; an adult requires 0.77 g protein a day per kg of body weight if the amino acids are derived from vegetable and animal sources.59 A 65 kg adult need only consume 37 g of meat, or 60 g of meat and vegetable protein, to satisfy his daily amino acid requirements.

The small and often seminomadic habits of groups that live in interfluve areas of Ama- zonia are not a vignette of the past. Most tribes have been drastically reduced, or have died out, since contact. During the first half of this century, at least eighty-seven tribes have become extinct in Brazil, mostly in the Ama- zon region. Introduced diseases have often devastated immunologically virgin groups.60 Violent conflicts with rubber tappers, cat hunters, settlers, and cattle ranchers have also checked the establishment of large, sedentary aboriginal populations.61

Other cultural factors operate to keep some groups small, such as fissioning because of in- tratribal disputes.6 A group may abandon a village site because of superstition and fear of the deceased.63

Caron, Cure d'Indiens (Paris: Union Gen6rale d'Editions, 1971), p. 278.

59 "Energy and Protein Requirements," World Health Organization, Technical Report Series, No. 522, pp. 1- 118.

60 D. Ribeiro, "Indigenous Cultures and Languages of Brazil," in J. Hopper, ed., Indians of Brazil in the 20th Century (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 and the Indians of Brazil (Cambridge: Cambridge University Press, 1977).

62 p. Lima, "Os Indios Waur'," Boletim do Museu Nacional, 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.

63 E. Galvdo, "Cultura e Sistema de Parentesco das

CONCLUSIONS

Numerous terra preta sites in the Amazon basin provide strong evidence that precontact native populations were in many cases large and sedentary, particularly along rivers. Un- like other areas of Latin America, there are no careful colonial records on aboriginal pop- ulations for Amazonia. Nevertheless, based on missionary reports, accounts of early trav- elers, and estimates of the carrying capacity of various environments, Denevan suggests that there may have been as many as 6.8 million Indians living in the region toward the close of the fifteenth century.64

Denevan's figure is much higher than has hitherto been proposed. Wagley allows only 1 million for the Amazon basin in 1500.65 But even Denevan's 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. The disappointing results of the efforts to colonize the interfluves of Amazonia along pioneer roads should not be blamed on the biophysical environment. Settlement problems are due more to cultural, rather than ecological, limi- tations .66

Biologists should be wary when they dis- cuss virgin Amazonian ecosystems. Potsherds and black earth may lurk under control plots and pristine nature reserves. What appears to be untouched wilderness could have been a garden plot, or a bustling village, hundreds or thousands of years ago. The savannas of Ro- raima and the grasslands of Marajo Island are due partly to man-made fires. Open campina scrub on sandy soils was once cleared by In- dians.67 More cultural surprises await beneath the 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 of the Americas in 1492 (Madison: University of Wisconsin Press, 1976), pp. 205-34.

";5 Wagley, op. cit., footnote 28, p. 272. 66 N. Smith, "Agricultural Productivity Along Brazil's

Transamazon Highway,' Agro-Ecosystems, Vol. 4 (1978), pp. 415-32.

67 Prance and Schubart, op. cit., footnote 10.