Amazonian and Caribbean agriculture
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Crops of the Amazon and Orinoco regions: their
origin, decline and future
Cupuaçu (Theabrom a grandiflorum)
Peach-palm (Bactris gasipaes)
Species of paullinia with economic potential
Arazá (Eugenia stipitata)
Feioja (Feijoa sellowiana)
Guinea arrowroot (Calathea allouia)
Maté (Ilex paraguariensis)
Tannia, yautia (Xanthosoma sagittifolium)
Crops of the Amazon and Orinoco regions: their origin, decline and future
Origins of agriculture and genetic diversity
The decline of the amazon and orinoco regions
Current erosion of genetic and cultural resources
Crops and wild species that deserve attention
New directions for neotropical agricultural development
Over the last 10 000 years, the landscapes of the Amazon and Orinoco regions have been dominated by numerous types of forest, mainly rain forest, with fields along the southern and northwestern edges. Such an immense area, which occupies almost half of South America, if the tropical forests of the Guyanas are included, may be called ecological Amazonia. As well as being ecologically continuous, there are seasonably navigable connections between the three major drainage basins: Orinoco, Amazon and Paraguay. The Amazon and Orinoco regions are joined physically and ecologically, so it is not difficult to assume that they might once also have been joined culturally.
Recent archaeological findings in northwestern Brazil suggest that the Amerindians discovered South America 40 000 to 50 000 years ago. Their migrations and cultural development can be delimited with some degree of accuracy during the last 5000 to 10000 years through a study of the languages, archaeology and agricultural history (crops and other useful plants).
Lathrap proposed the hypothesis that Amazonia is an important centre of origin of agriculture. His interpretation of archaeological remains identified central Amazonia as the primary centre. The phytogeography of the crops domesticated by the Amerindians suggests that the area of greatest genetic diversity is northwestern Amazonia. The domestication of medicinal and magical plants and plants for other purposes supports this hypothesis, as does the genetic diversity of cassava (Manihot esculenta), which is ecological Amazonia's greatest contribution to world agriculture.
Today it is becoming increasingly clear that the Amerindians' adaptation to the ecosystems of the Amazon and Orinoco regions was much more complex than can be deduced from an analysis of their farming techniques. According to Denevan, at the time of their contact with Europeans there were at least five to six million people living in the Amazon region. There were perhaps two million more in other parts of ecological Amazonia. The pressure exerted by this population was very limited in relation to the region's demographic capacity. This situation contrasts with the situation prevailing at present: a population of 20 to 30 million inhabitants living in poverty, urban settlements which require food and materials to be imported and severe environmental degradation.
Five hundred years after the first contact, it is now recognized that the original inhabitants of Amazonia had an unrivalled agro-ecological knowledge, especially compared with what exists in the region today. In many respects, Andean civilizations were also more advanced than the European adventurers who conquered them. Nowadays it is difficult to practice moderately sustainable agriculture in Amazonia, and self sustainable agro-ecosystems are far from being developed in the humid tropics, owing to population pressure and the economic model that has been chosen. Whatever can be learned from the last Amerindians will help to set up more sustainable systems from an ecological, economic and social point of view.
However, one needs to be aware that cultural conservation is as important in Amazonia as biotic conservation. With the removal of the indigenous populations, a great deal of ecological and agro-ecological knowledge has been lost. The 300 000 to 700 000 people who inhabit the region nowadays are physically and culturally impoverished.
Origins of agriculture and genetic diversity
The very early dates of the discovery of South America by the Amerindians shifted the time-scale in which humans adapted to the rain forest.
Penetration and further colonization of this area by hunters and gatherers depended on the distribution and availability of food resources. During the rainy season there was an abundance of fruits and nuts which could feed large populations, especially in the regions along the rivers, but during the dry season plant resources were scarce. However, the newly arrived Amerindian population was small. Fish in the Amazon region was also seasonally plentiful and was an important source of protein which was easily obtained using simple techniques.
The combination of fruits, nuts, fish, reptiles and mammals constituted a very attractive concentration of natural resources. It can be assumed that colonization of the Amazon region began as soon as these resources were discovered. According to Lathrap, in an environment such as a tropical forest, with scarce resources during certain seasons of the year, it is highly likely that the Amerindians tried to concentrate these resources by sowing food plants (fruit-trees, nuts, leaves, roots) and other plants with various uses in more accessible places. If fruit and nuts were one of the main foods during the rainy season, such species were probably the first to have been tended, whereas root crops must have been domesticated later. These practices subsequently evolved into the complex system of agroforestry and forest management which is to be found today in Amazonia and neotropical regions in general.
Agroforestry is a very efficient system for improving crops, as it allows rapid genetic progress if there is sufficient variability. Over the millennia, the genetic basis necessary for modifying and completely domesticating numerous annual and perennial species in the Amazon region has been developed.
Taking as his basis the domesticated and semidomesticated perennial fruit crops, the author proposed the establishment of a centre of genetic diversity in northwestern Amazonia, despite recognition of a wide diversity outside this centre. Table 6 shows 21 perennial, fruit-tree and industrial species from the Amazon and Orinoco regions which support the hypothesis of this centre of diversity or of a very early domestication in ecological Amazonia outside this centre.
Cassava, sweet potato (Ipomoea batatas), tannia (Xanthosoma sagittifolium) and other less important roots became the staple food of the region and were taken to other parts of the neotropics and later to the rest of the world. Although coca (Erythroxylum coca) is considered an Andean crop, there is also a domesticated variety, Ipadú, in the lowlands. The domesticated or semi-domesticated plants of Amazonia which were important to Amerindian cultures for ritual and medicinal uses also have a potential for exploitation in modern society.
The decline of the amazon and Orinoco regions
The decline of the Amerindian societies of ecological Amazonia began before the first direct contact with the European adventurers. The extent of this decline before 1542, when Francisco de Orellana descended the Napo and Amazon Rivers, is unknown but it is believed that European diseases reached the interior of the region before the Spanish and Portuguese, coming from the Andes and especially from the Caribbean.
FIGURE 22 The Amazon and Caribbean region
TABLE 6 Domesticated and semi-domesticated perennial fruit-trees and technological crops of the Amazon and Orinoco regions
|Ananas comosus||Bromeliaceae||Southwestern Amazonia|
|Annona muricata||Annonaceae||Northern South America|
|Bactris gasipaes||Palmae||Southwestern Amazonia|
|Bixa orellana||Bixaceae||Northern South America|
|Borojoa sorbilis||Rubiaceae||Western Amazonia|
|Carica papaya||Caricaceae||Northwestern South America|
|Crescentia cujete||Bignoniaceae||Western Amazonia|
|Eugenia stipitata||Myrtaceae||Western Amazonia|
|Lonchocarpus utilis||Leguminosae||Western Amazonia|
|Macoubea witotorum||Apocynaceae||Central Amazonia|
|Passiflora edulis||Passifloraceae||Northern South America|
|Paullinia cupana||Sapindaceae||Central Amazonia|
|Poraqueiba sericea||Icacinaceae||Western Amazonia|
|Pourouma cecropiaefolia||Cecropiaceae||Northwestern Amazonia|
|Pouteria caimito||Sapotaceae||Northern South America|
|Quararibea cordata||Bombacaceae||Northwestern Amazonia|
|Rollinia mucosa||Annonaceae||Northern South America|
|Solanum sessiliflorum||Solanaceae||Northwestern Amazonia|
|Theobroma cacao||Sterculiaceae||Northwestern Amazonia|
Although depopulation is the main indicator of the loss of cultural knowledge, a better index is the number of tribes wiped out during this process, since the disappearance of an ethnic group means that all its acquired knowledge and most of its agricultural artefacts (including the varieties of its crops) have also vanished. With a loss of between 90 and 95 percent of the original population, it is estimated that at least 80 percent of the ethnic groups have disappeared.
According to Lathrap, the Omagua nation in western Amazonia was completely destroyed 100 to 200 years after the arrival of the Europeans. The chronicler of Orellana's expedition, Carvajal, recorded that numerous types of cultivated fruit-trees were grown in the villages which obviously indicates that they were important components of the Amazonian diet. Fortunately, numerous cultivars of cassava, including those from floodable areas that are harvested in six months, and cultivars of numerous fruit species, remained in the region as disquieting reminders of what the diet had been like before contact had been made with the Amazonian peoples.
Each tribal group had its own stock of knowledge on useful and cultivated plants, originally obtained from the surrounding forest or imported as cultivated or domesticated forms from other areas. Each Amerindian nation may be considered as a source of different knowledge. What remains of the few that still exist needs to be conserved, not only for obvious ethical reasons, but also for economic reasons connected with the future of the Amazon region. However, the decline of ecological Amazonia has not yet reached its maximum point and the erosion of its genetic diversity and biodiversity has accelerated in recent years.
Current erosion of genetic and cultural resources
Some governments of the Amazon countries are beginning to help the remaining Amerindians to resist the continuous process of acculturation, especially in Colombia. Although acculturation and population reduction are the main reasons for the erosion of genetic resources, the integrity of these resources is also threatened by other factors. The biggest threat is the rural depopulation of the Amazon peasants, many of whom are of Amerindian descent. The problem is especially serious in Brazil, where they are called caboclos. In the areas where the Amerindians were eliminated or which they abandoned. the caboclos are the heirs of what is left of the Amerindian heritage, including crops. When the caboclos emigrate, the crops disappear because of the competition from secondary vegetation. The caboclo culture also needs to be conserved. through support from governments, especially through development programmes, so that the people may maintain their lifestyle.
Another threat is the immigration of non-Amazonian groups. In Spanish-speaking Amazonia, it is the Andean or coastal peasants who are being settled with the support of their governments or simply because they have abandoned the increasingly poor mountains for the supposedly richer lowlands. In Brazilian Amazonia, it is the peasants expelled from the fertile lands of the south who go in search of new land on which to live. None of these groups knows the Amazon ecosystem, nor do they want to learn from the local experts, Amerindians or caboclos.
The big cattle ranches and other development projects (mining, hydroelectric systems) are a further threat, since they deforest large areas in order to obtain short-term income. These projects are active agents in the acculturation of the Amerindians, rural depopulation and the immigration of non-Amazonians. They are promoted by all the governments of the region, often through direct subsidies. Recent calculations, published by Fearnside, indicate that between 6 and 8 percent of Brazilian Amazonia has been deforested, with most of it being given over to stock farming as part of large-scale projects. In other instances, it is so degraded that it is not possible to sustain human populations adequately.
The conservation of genetic and cultural resources. and of biodiversity in general, will be possible only as part of a regional development programme. A sustainable. permanent and varied agriculture must be the basis of this programme, which will only be feasible if new species and technologies are developed. Many of these species already exist and others can easily be found being managed, cultivated and domesticated by indigenous communities in the Amazon region. Technologies must be developed from indigenous and caboclo techniques and cultures, with the necessary modifications made for dealing with the needs of the more numerous populations of today and the future, under a market economy.
Crops and wild species that deserve attention
Ecological Amazonia has supplied a number of important crops for world agriculture and can still offer many more if scientific research and entrepreneurial action are directed towards this end. Cassava, which has already been mentioned, is considered to be the sixth most important crop in the world's diet. Tannia (Xanthosoma sagittifolium), the Brazil nut (Bertholletia excelsa), peppers (Capsicum spp.), pineapple (Ananas comosus), cocoa (Theobroma cacao) and rubber (Hevea brasiliensis) originate from this region. This section will deal only with certain groups of perennial species which have a potential for more widespread use.
Palms are a natural group including at least a dozen species with a high potential. The peach palm or pejibaye (Bactris gasipaes) is the only palm of the neotropics which has been domesticated and has several potential uses in both advanced and subsistence farming.
The Jessenia/Oenocarpus complex contains several palms which were very important for subsistence in the region. Jessenia bataua contains oil in the mesocarp which is almost indistinguishable from olive oil (Olea europaea) and, moreover, is an excellent-quality protein. The genus Astrocaryum is very popular because of its fruit which is eaten fresh. Some species have potential as oilseed crops. Mauritia flexuosa and Euterpe oleracea are dominant species on the flood plains of the big rivers, where the majority of agricultural crops do not prosper, and they produce enormous quantities of fruit with little care and no fertilization. E. oleracea is the species which produces the greatest quantity of palm hearts for the world market. Orbignya phalerata is another dominant species, found in the southern limits of the Amazon region, which produces millions of tonnes of fruit which is rich in oil and starch and has an excellent woody endocarp for the preparation of carbon. Other palms provide fruit, fibre and building materials and have enormous potential as ornamental plants.
There are numerous nuts and species with seeds similar to nuts. The best known is the brazil nut, which is sown and widely used by the Amerindians as well as other inhabitants of the region and exported to international markets. A related species is the paradise nut, Lecythis pisonis, which has a better flavour but which is very difficult to gather, as the fruit does not fall from the tree when it is ripe. In the north, the souari nut, Caryocar nuciferum, was once important and may become important again. In Peru, a related species, Caryocar glabrum, is widely used and could be converted into an export crop if it were adequately researched. Caryodendron orinocensis is a promising species which is receiving a certain amount of attention in Colombia. Couepia longipendula, found in Manaus, is distinguished by its delicate flavour, earliness and growth in cultivation. The cashew, Anacardium occidentale, is native along the Brazilian coast to the south of ecological Amazonia. There are at least two related native species from the rain forests that merit investigation. Other species of nut should be the subject of scientific and market studies because of their ease of preparation, use and marketing.
Several fruits with mesocarps rich in oil and starch were important native resources managed and cultivated by the Amerindians. This group includes Poraqueiba sericea, a cultivated fruit species whose origin is unknown. It is domesticated and widely grown throughout the region and forms the basis of an agroforestry system aimed at the Iquitos market in Peru. Caryocar villosum is used mainly for its oily and starchy mesocarp and has an excellent-flavoured nut.
The succulent, aromatic fruit is abundant and can offer new options both for the fresh and processed fruit markets. The Smooth cayenne pineapple originated in the Orinoco region and is the predominant cultivar throughout the world, especially for processing.
Of the numerous domesticated or cultivated species studied by Cavalcante (1988), only a few may be mentioned here. The South American sapote or sapodilla, Quararibea cordata. has a resilient skin which enables it to be transported and stored easily. It has a sweet, succulent, delicious, orange flesh. The arazá, Eugenia stipitata, has a delicious aroma and exquisite flavour, but is extremely sour. However, it does have a great potential for processing in the agrifood industry. The camucamu (Myrciaria dubia) is the wild species which contains a greater quantity of vitamin C than any other fruit (±4 g per 100 g). The cupuaçu, (Theobroma grandiflorum) is a species related to cocoa whose flesh has a strong, bitter-sweet flavour and which is very suitable for juices or ice-creams.
Species rich in various types of essential oils are common in ecological Amazonia, as are others which produce oil, resins, gums and latex. Palo rosa, Aniba roseodora, which is now almost extinct owing to destructive exploitation, is used to obtain an essential oil which is in great demand on the perfume market. The leaves have been found to contain even more oil than the trunk, and it could be harvested in a sustainable rather than in a destructive way. Copaifera multijuga produces a liquid oleoresin directly in its trunk which can be used as a substitute for diesel. It also has a medicinal use and its application is being studied in the cosmetics industry. The sowa or sorva, Couma utilis, exudes a nonelastic gum which is used in chewing gums. Synthetic chicle is the component of most gums, but sowa gum has not yet been synthesized and is collected from wild trees. Unfortunately, its collection is also destructive, although it has been shown that, like rubber, it could be harvested in a sustainable form.
There are more than 100 timber-yielding species, although only about two dozen are widely marketed. As the reserves of Asia and Africa dry up, Amazonia is becoming the focus of excessively destructive exploitation since, to date, none of the region's governments has vigorously regulated forestry activity. Genetic resources are being eroded very quickly and this process can only be halted if forest management controls exploitation.
This chapter has dealt basically with the wild and cultivated perennial species, since the forest needs to be conserved not only because it is an important element in the planet's ecological balance, but because it contains irreplaceable natural and artificial products and systems. The only way of conserving it is to find development models that consider forest ecosystems and their related activities to be more valuable than timber or pasture land. The governments of the Amazon countries need to draw up sustainable development programmes which are fair for all inhabitants of the region.
New directions for neotropical agricultural development
Recognizing the value of forests is essentially a political question, since research has shown that the products extracted and scientific forest management prove to be of greater value in the long term than any of the alternatives currently practised in ecological Amazonia. This is especially true when a well-planned collection or scientific forest management system is compared with conventional agriculture on poor Ultisols and Oxisols. Collecting from wild populations is frequently seen as an imperfect system which needs to be improved by development. However, the shortcomings in this form of exploitation seem to derive more from the approach to planning at a government and international development agency level. These bodies consider it to be basically a subsistence strategy that is closely connected with rural poverty. In actual fact, as Altieri, Merrick and Anderson (1987) have shown, collecting can be turned into an important economic factor and. in the rural framework, it is already an activity that prevents many families from descending into absolute poverty.
It will obviously be impossible to maintain the whole forest area of Amazonia because it is being felled very rapidly and it would prove difficult to halt its destruction immediately. However, what is more important is that there are no proven alternatives to win the support of governments and inhabitants. For this reason, the scientific institutions of the Amazon region and their collaborators in other regions ought to develop a programme with three simultaneous approaches in order to identify a good number of new crops for the market. This programme should include conventional agriculture (monoculture), agroforestry and multipurpose forest management, and its subject should be perennial instead of annual crops.
Conventional agriculture does not require any comment, as all institutions of the region know it well. However, not all native species can be used for this model of agriculture since, when they are sown in greater densities than is normal in the traditional ecosystems or agro-ecosystems, they may be susceptible to pests and diseases that have evolved with them. An example is Caryodendron orinocensis, from northwestern Amazonia which grows at low density in the forest or in indigenous agroforestry systems. When the Araracuara Corporation organized a germplasm collection in San Jose de Guaviare and sowed it in a well-designed monoculture, C. orinocensis was immediately attacked by a leaf caterpillar which almost paralysed the plants' growth and made it impossible to characterize and evaluate them. This type of problem could occur in many indigenous species and it is the main reason for following a triple-approach programme.
"Agroforestry" is a new name for a very old practice which combines several crops in an ecologically integrated unit. Indigenous agroforestry -the traditional agricultural practice of ecological Amazonia - is one form of this type of exploitation. Throughout the world, agroforestry is practiced by small farmers, since it is relatively labour-intensive. It contrasts with the conventional agriculture of the First World, which is capital-intensive. Development may also be based on labour instead of capital, especially since labour in the neotropics is relatively plentiful, whereas capital is less so.
Multipurpose forest management is a practice whereby a section of the forest is managed for the benefit of the greatest number of people. Conventional forest management, by contrast, has frequently excluded the region's original inhabitants and only benefited the big landowners and corporate entities. A multipurpose system of forest management should be aimed at enriching the forest with species that produce fruit, nuts, latex and essential oils as well as timber-yielding species. In this way, the forest can be harvested in different ways throughout the year to the benefit of the communities which inhabit them, instead of benefiting just a few people. Brazil's reservations may evolve towards this type of system, although the research necessary would have to be greater than in the other two approaches mentioned.
Agroforestry and multipurpose forest management require multidisciplinary research which must begin with ethnobiology and which must study the agricultural practices and customs of the Amerindians and caboclos. Geneticists, horticulturists and forestry experts must improve not only the genetic material used but also the indigenous exploitation systems which are perhaps not sufficiently market-orientated to be attractive to the majority of farmers, extensionists and government planners. These activities must be carried out in collaboration with business in such a way that priorities are established in terms of the market.
The future development of ecological Amazonia needs to be planned to benefit the region's inhabitants without degrading the natural environment. Conservation of cultural and genetic diversity and biodiversity must be the essential features of this programme. Forests need to be recognized as a valuable resource, and agricultural agroforestry and management practices must be devised in such a way that this resource can be exploited rationally instead of being destroyed.
Altieri, M.A., Merrick, L.C. & Anderson, M.K. 1987. Peasant agriculture and the conservation of crop and wild plant resources. Conserv. Biol., 1: 49-58.
Cavalcante, P.B. 1988. Frutas comestíveis da Amazônia, 4th ed. Souza Cruz, Belém, Brazil, Museu Paraense Emilio Goeldi.
Clement, C.R. 1988. Domestication of the pejibaye (Bactris gasipaes): past and present. Adv. Econ. Bot., 6: 163- 180.
Clement, C.R. 1989. A center of crop genetic diversity in western Amazonia. Bioscience 39: 624-631.
Clement, C.R.1991. Amazonian fruits: neglected, threatened and potentially rich resources require urgent attention. Diversity, 7: 56-59.
Denevan, W.M. 1976. The aboriginal population of Amazonia. In W.M. Denevan, ed. The native population of the Americas in 1492 p. 205-234. Madison, USA, University of Wisconsin Press.
Fearnside, P.M. 1988. An ecological analysis of predominant land uses in the Brazilian Amazon. The Environmentalist. 8: 281 -300.
Lathrap, D.W. 1977. Our father the Cayman, our mother the gourd: Spinden revisited, or a unitary model for the emergence of agriculture in the New World. In C.A. Reed. ed. Origins of agriculture p. 713-752. The Hague, Mouton.
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