Anthrosols and human carrying capacity in amazoniaPresentation Transcript
Anthrosols and Human Carrying Capacity in Amazonia
Author(s): Nigel J. H. Smith
Source: Annals of the Association of American Geographers, Vol. 70, No. 4 (Dec., 1980), pp.
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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
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
* 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
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.
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-
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
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.
matbones 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
The impressive number of terra preta sites
along the Trombetas and Jamundacrivers 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'riosdo 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,
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.10This 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.
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 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 anthropogenicor-~~~~~~~~~...........
FIGinofAtrooe black earthhae 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.
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
fromjet 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 duringthe 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
00 T UARA
FIG.S 2.Loaiosofalakeat ste amld nth Ara nA mo
TACOATIARA ~ ~ MRAB
* ANTHROPOGENICBLACKEARTH 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
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
19Only 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.
earth max. Surrounding
Site Location Vegetation area ha depth m soil type Observa
I Gleba 24, lot 20, km 77 Arara Indian field 4 1.5 0.40 Terra roxa Sherds abunda
Altamira-Itaituba, yrs old to depth of 1
Transamazon, Pard. roughly circu
Perennial stream 300 m
2 Gleba 34, lot 17, km 105 Colonist field in 5.0 0.20 Red- Sherds found b
Altamira-Itaituba, coffee, 1 yr old, yellow depth, stone
Transamazon, Para. cleared from latosol roughly circu
Perennial stream 300 m mature forest
3 Agropolis Miritituba, right Open area in weeds, 10.0 0.20 Yellow Sherds and sto
bank of Tapaj6s River, cleared from latosol on surface an
Pard. secondary forest cm. Site stre
bank and 10
4 Itupiranga, left bank of Open area in grass 4.0 0.70 Red- Sherds and celt
Tocantins River, Pard. and mango trees yellow to depth of 5
5 Gleba 24, lot 26, sideroad km Open area by 1.0 0.40 Yellow Sherds on surf
80 Altamira-Itaituba, COBAL store, latosol of 10 cm. Sit
Transamazon, Pard. cleared from forest in shape.
Perennial stream 400 m 2 yrs ago
6 Gleba 31, lot 12, sideroad km Mature forest 0.5 0.87 Terra roxa Sherds at 15 cm
100 Altamira-Itaituba roughly circu
Perennial stream 200 m
7 Km 139 Itacoatiara-Manaus, Campina 0.5 0.20 Podzol Sherds frequen
Amazonas. Perennial to depth of 2
stream 300 m away. lenticular in
8 Atlantic veneer mill, Open weedy area 30.0 1.00 Yellow Sherds abunda
Itacoatiara, left bank of latosol frequent on
Amazon River, Amazonas. depth of 10 c
km along ban
9 Lago de Terra Preta, 30 km Maize and squash 0.8 0.45 Red Sherds on surf
S.E. of Itacoatiara, field 2 yrs old. latosol depth. Site e
Amazonas. Bluff Cleared from 2nd along margin
overlooking blackwater growth inland.
earth max. Surrounding
Site Location Vegetation area ha depth m soil type Observation
10 Entrance to Lago de Batista, Cacao grove some 40 0.4 0.4 Yellow Sherds at 10 cm d
25 km S.E. of Itacoatiara, yrs old latosol extends 50 m alo
Amazonas. Bluff lake and 80 m in
11 Km 2 Aripuana-Colonia dos Mature forest 0.5 0.20 Latosol Sherds and celts to
Patos, northern Mato Site roughly circ
Grosso. Perennial stream
500 m away.
12 Aripuana, right bank of Open, town streets 24.0 0.50 Yellow Sherds and celts f
Aripuana River, northern and square latosol cm depth. Site l
Mato Grosso. shape.
13 Lago de Madruba, 6 km Open grassland 0.5 0.50 Podzol Sherds numerous
north of Itapiranga, Am. depth. Site exten
Margin of blackwater lake. along margin of
14 Itapiranga, left bank of Open backyard 8.0 1.00 Yellow Sherds abundant o
Parand Silves, Amazonas. latosol to depth of 50 c
extends 800 m a
100 m inland.
15 Terra Nova, Parand do I yr 2nd growth 45.0 0.90 Yellow Sherds common o
Silves, 1 km west of latosol to 50 cm depth.
Itapiranga, Amazonas. for 1.5 km along
16 Gleba 24, lot 8, km 74 Manioc field 0.3 0.15 Podzol Sherds abundant o
Altamira-Itaituba, to 15 cm depth.
Transamazon, Pard. in shape.
Perennial stream 30 m
17 Missdo, left bank of Xingu Open area with weeds 90.0 0.68 Yellow Sherds and celts a
River, 1.8 km south of latosol surface and to 1
Altamira, Pard. Site extends 1.8
bank and 500 m
18 Praia Dourada, Tarumd Open grassland with 3.2 1.47 Yellow Sherds abundant t
River, 15 km N.W. of weeds podzolic Celts. Site exten
Manaus, Am. Blackwater along river and
19 Tapurucuara, Rio Negro, Open grassland 7.0 1.09 Red- Sherds common o
Amazonas. yellow to depth of 85 c
podzolic extends 700 m a
100 m inland.
earth max. Surrounding
Site Location Vegetation area ha depth m soil type O
20 Campina, estrada de Terra Campina 1.0 0.24 Podzol Sherds on
Preta, sideroad at km 4 depth. S
Am. Margin of perennial
21 Km 4 Cacau Pirera- Early 2nd growth 4.0 0.84 Red- Sherds abu
Manacapuru, Am. Margin yellow to 70 cm
of perennial stream. podzolic lenticula
22 Estrada de Terra Preta, Campinarana forest 0.5 0.20 Podzolic Sherds infr
sideroad at km 4 Cacau to 20 cm
Perennial stream 200 m
23 Ponta das Lajes, Rio Negro, 2nd growth of several 6.0 0.25 Yellow Sherds abu
Manaus, Amazonas. years latosol 25 cm d
24 Km 8 Ponta Negra road, Campinarana 35.1 1.41 Podzol Sherds inf
Manaus, Amazonas. to 5 cm
2.7 km a
25 Ceramica Irco, km 15 Aleixo Grassland 0.8 0.50 Yellow Sherds abu
road, Manaus, Am. Bluff podzolic Site exte
overlooking Amazon. and 60 m
26 Manacapuru, Amazon River, 2nd growth of several 80.0 1.00 Yellow Sherds abu
Amazonas. years latosol depth. S
27 Itaituba, Tapaj6s River, Pard. Open, bare ground 15.0 0.45 Yellow Sherds rar
latosol cm dept
28 Gleba 12, lot 7, km 30 Backyard weeds, 0.7 0.35 Podzolic Sherds num
Altamira-Maraba, cleared from forest 10 cm d
Transamazon, Pa. Margin 8 yrs ago
of perennial stream.
29 Km 30 Itaituba-Altamira, Open, bulldozed 1.6 0.25 Latosol Sherds num
junction of Transamazon 15 cm d
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
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,
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-
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
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.29Animal 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
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.
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.
27 Ranzani et al., op. cit., footnote 12.
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.
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
UTILIZATION OF ANTHROPOGENIC
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.32The Maw6 In-
dians favor anthropogenic epipedon to grow
guarandvines (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-
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 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.39But surprisingly, twelve of the twenty-
nine sampled black earth sites are in upland
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,
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
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.40Three 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
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
2-4 No description Trombetas and
<3 Circular Belterra plateauc
2-3 Lenticular Belterra plateau'
0.2-0.4 No description Maraj6, Caviana
0.03-0.07 Circular or oval North central
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
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
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.
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
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.47The 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
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-
50 R. MacNeish, "Early Man in the Andes," Scientific
American, 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 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 terrafirtme 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),
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
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
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-
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.
61 S. Davis, Victims of the Miracle: Development and
the Indians of Brazil (Cambridge: Cambridge University
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.
E. Galvdo, "Cultura e Sistema de Parentesco das
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 1500.65But
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-
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.67More 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.
Prance and Schubart, op. cit., footnote 10.