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As in the case of extractive reserves, attempts to manage forests in Amazonia for timber or charcoal production are in their infancy (FAO 1990: 11; Fearnside 1989c; Kirmse, Constantino, and Guess 1993; Silva and Uhl 1992; Whitmore 1990: 126). Current wood-harvesting practices for timber in the region often damage the recuperative capacity of the forest.
Traditionally, most of the lumbering in Amazonia has been concentrated along rivers where access to timber is easier. Ucuúba (Virola surinamensis), however, has been logged out of much of the flood-plain forests. As pioneer highways started slicing across the uplands in the 1960s, loggers penetrated deeper into the forest, such as around Itacoatiara near Manaus, and along feeder roads off BR 364 in Rondônia (Browder 1989a; Wesche and Bruneau 1990: 59).
The tempo of timber extraction in Amazonia continues to increase as the regional network of roads expands. The number of licensed sawmills in the Brazilian Amazon increased seventeen-fold between 1952 and 1982 (Browder 1989a). Between 1985 and 1987 alone, the number of sawmills operating in the municipality of Rio Branco in Acre almost doubled, from 23 to 44 (FUNTAC 1990a: 50). In 1973, 287 sawmills and 5 plywood and veneer plants were registered in the Brazilian Amazon; by 1986, the number of sawmills and plywood plants had grown to 2,231 and 70, respectively (Yared and Brienza 1989). Between 1975 and 1984, log production nearly quadrupled in the Brazilian Amazon to 17.4 million m, reaching 24.6 million m by 1988 (Anderson 1987; Browder 1989a; Silva and Uhl 1992). The North region is now Brazil's foremost source of industrial sawlogs, and Pará is the leading producer of timber in the Brazilian Amazon (Homma 1989b).
The advent of larger trucks in the Brazilian market has increased the effective logging radius of sawmills. Longer and more powerful trucks, made by such companies as Mercedes Benz and Volvo, have payloads of 28 tons, in comparison with the 13-ton capacity typical of yesteryear. Larger trucks can profitably pick up logs as far away as 200 km, and, by making two trips a day, can bring back 80 m3 of wood. The smaller trucks are essentially confined to a 100 km radius from sawmills.
Paragominas, a cattle town founded in the mid-1960s along the BelémBrasília highway, has emerged as the most important logging centre in the Brazilian Amazon (fig. 4.3). In 1992,140 sawmills were operating within the urban fringe of Paragominas (D. Callegario, pers. comm.). Other major concentrations of sawmills in Pará are found in the vicinity of Tailândia along the PA 150 highway, Tucurui and Goianeza, and around Tomé-Açu. The municipality of Tailândia alone has 73 registered sawmills (W. Kronbauer, pers. comm.).
The quickened pace of the timber trade has raised questions about the sustainability of logging practices. In a study of a logging operation near Paragominas, Pará one-quarter of the trees with a diameter at breast height of at least 10 cm were killed or severely damaged by logging activities (Uhf and Vieira 1989). The canopy cover was reduced by half. The amount of damage from logging appears to vary widely, however. In parts of Indonesia, loggers sometimes damage as much as 70 per cent of the remaining trees (Whitten et al. 1987: 480).
Logging does not always damage most of the trees or destroy half the canopy. If only a few desirable species are removed, as is typically the case in the Brazilian Amazon, perhaps only a quarter of the canopy is usually affected. During a 40 minute overflight of forest patches on heavily logged ranches near Paragominas in April 1991, only 1030 per cent of the canopy had been torn open. Light gaps are important for generating many commercially important timber trees, such as mahogany (Kirmse, Constantino, and Guess 1993).
Loggers largely ignore regulations designed to conserve timber resources and protect valuable fruit and nut trees. Brazil nut trees are avidly sought by sawmills because of their durable and lustrous red-brown wood. Although it is illegal to cut down Brazil nut trees, landowners frequently allow loggers to remove the trees, particularly if they need cash. A Brazil nut tree can be legally cut down if it is dead or dying or in the way of urban expansion. In the early 1970s, some Transamazon colonists deliberately lit fires at the base of Brazil nut trees to obtain a cash windfall from loggers. In the late 1980s, some loggers in parts of northern Mato Grosso obtained permits to fell Brazil nut trees deemed in the way of urban expansion, even though some of the trees were several kilometres from the nearest house (Rubens Lima, pers. comm.).
Piquiá, another canopy-emergent in the Amazonian forest, is also persecuted by loggers even though it provides a widely appreciated fruit. The light yellow pulp of piquia fruits is cooked and relished in April and May, particularly by poorer people. Piquiá also produces an excellent hardwood, and many trees are converted to handsome yellow-brown tables, chairs, doors, and dugout canoes.
As the more desirable species become scarce in heavily logged areas, sawmills shift to second- and third-tier species. The Rosa Madeireira sawmill in Paragominas, for example, was working with 58 named timber trees in the early 1990s. Some common names of timber trees encompass several species: faveira, a widely used leguminous timber, includes species in several genera, such as Enterolobium, Macrolobium, Parkia, Piptadenia, Stryphnodendron, Vataireopsis, and Vatairea. Rosa Madeireira actually processed over 100 species of timber trees in 1990, some of which are used for veneer production. In July 1992 alone, Dalsam Madeiras of Paragominas processed logs from 47 timber species (table 4.7).
Where road conditions are less favourable, such as in the Marabá area, sawmills tend to work with fewer, more valuable species. Madecil Serraria, the largest sawmill in Marabá, accepts only about 20 species, whereas the smaller Madeireira Marabá buys or harvests only 10 species (table 4.8). Ipê, particularly Tabebuia serratifolia, appears to be the most important timber tree in the Marabá area in terms of volume, whereas mahogany, known locally as mogno, is the most valuable species.
Table 4.7 Timber species and volume processed Into sawlogs at Dalsam Madeiras, Paragominas Pará, July 1992
|Common name||Scientific name||No. of logs||Volume (m)|
spp. and various
other Legume genera
|Angelim pedra||Hymenolobium petraeum||64||161|
|Louro vermelho||Nectadra rubra||32||73|
of Tachigalia and
|Quaruba cedro||Vochysia sp.||34||66|
|Louro canela||Ocotea dissimilis||26||48|
|Pau roxo||Peltogyne lecointe||21||45|
|Angelim vermelho||Dinizia excelsa||11||36|
|Sucupira pele de sapo||Diplotropis sp.||20||23|
|Orelha de macaco||Enterolobium schomburgkii||10||17|
Source: Dalsam Madeiras, Paragominas, Pará, August 1992.
One of the common perceptions about logging in Amazonia is that it is geared primarily to the export trade, particularly to industrial countries. In fact, most tropical timber is harvested for domestic consumption; less than onethird of tropical roundwood and processed wood is typically exported (Atkin 1993; Vincent 1992). International trade accounts for a diminishing share of consumption of tropical timber (Vincent 1992).
Although it is true that some of the premier woods, such as mahogany, are largely sent abroad, much of the timber production in Amazonia is for the domestic market (fig. 4.4). In the Paragominas area, sawmills send about 80 per cent of their production to markets in central and southern Brazil, such as Rio, Espírito Santo, Belo Horizonte, and in the North-east region. Dalsam Madeiras, a mediumsized sawmill in Paragominas, sends 80 per cent of its production to markets within Brazil. An estimated 90 per cent of the timber sawn at Tailandia is sent to national markets (W. Kronbauer, pers. comm.). Further south along the PA 150 highway in Marabá, Madeireira Marabá, one of about 20 sawmills in the rapidly growing town as of 1992, also dispatches 90 per cent of its planks to the Brazilian market, divided roughly equally between the North-east region and the South region (Sinisvaldo Mota, pers. comm.). In spite of the recession, de mend is growing for lower-quality timber for general construction purposes, such as moulds for concrete.
Table 4.8 Some timber species processed by sawmills in Marabá, Pará, 1992
|Local name||Scientific name||Madecil||Marabá|
|Angelim pedra||Hymenolobium petraeum||+|
The increased logging activity may ironically help save some forest stands. In the vicinity of Paragominas, for example, several ranchers have halted deforestation on their properties because of rising income derived from periodically selling logging rights to sawmills. The owner of Fazenda São João, which has 600 ha of pasture, "sold" his 400 ha of forest to sawmill operators in 1982, 1986, and 1988. Although the forest on the São João ranch was unlikely to yield sufficiently valuable timber to justify logging three more times in the 1990s, the shift to less desirable species means that cutting cycles of around a decade could generate reasonably high levels of supplemental income. In some cases, income derived from logging has been reinvested to upgrade pastures.
Another notable trend is for sawmills to acquire and manage land. In part, this shift to forest management is in response to the requirements of IBAMA for sawmills to have a "management plan" in order to operate, or to contribute to a fund for purchasing national forests. IBAMA has few inspectors to verify if such plans are being carried out, and one sawmill operator was curious why the national government had not done more to acquire forests for lease to timber companies. Demand for expertise in forest management is particularly strong in the vicinity of Paragominas, since many of the sawmills also own ranches with sizeable portions of their land still in forest. Offices have sprung up in various towns in the Brazilian Amazon, such as Marabá offering services in devising "forest management plans."
How well forests are being managed is unclear. In theory at least, blocks of forest are harvested on a rotational basis and care is taken to avoid damaging seedlings. At least some of the sawmills concerned with their long-term survival are apparently taking seriously the need to harvest trees in a rational manner. The larger sawmills, in contrast to the small, mobile ones, are more likely to practice some form of forest management because they often own land and have a greater fixed investment.
In the case of Paragominas, many of the sawmills own ranch or farm land with stands of forest. Dalsam Madeiras, for example, owns two ranches with a total area of 11,500 ha, 10,000 ha of which are in forest. Blocks of forest are logged on a rotational basis and most trees are cut only if they are larger than 1.2 metres in circumference. The more valuable species, such as ipê, sucupira (Bowdichia nitida), and freijó (Cordia goeldiana), are felled even if they are smaller than 1.2 metres in circumference. Near Tailândia, the W.K. Brasil sawmill owns 2,778 ha of forest, of which 1,000 ha are currently managed. Half of the sawmills in Tailandia now own forest (W. Kronbauer, pers. comm.).
The Madeireira Marabá sawmill processes some 12,000 m of logs a year and has a project to manage 3,500 ha. With a yield of some 40 m/ha in the forests within 200 km, this medium-sized sawmill harvests timber from some 300 ha annually. The 3,500 ha management area is unlikely to sustain a cutting cycle of about 12 years for long. Tropical foresters generally recommend longer cycles, such as 70 years in the case of the dipterocarp forests of Indonesia (Whitten et al. 1987: 481). One problem that sawmills are encountering with acquiring land for forest management is that definitive title to large holdings must be approved by Congress, a time-consuming, expensive, and unpredictable process.
At km 101 of the Santarém-Cuiabá Highway, CEMEX (Comercial Madeiras Exportação, S.A.) owns 6,900 ha, mostly in forest, of which 2,930 ha are managed on a 12-30-year cutting cycle (fig. 4.5). On the first cutting cycle, 70 m are removed; it is not known whether this relatively high extraction rate is sustainable, since CEMEX has been managing forest for only six years. The minimum size at which trees are harvested varies by species: jatobá (Hymenaea courbaril), for example, is allegedly cut only when its diameter at breast height (dbh) reaches 60 cm, whereas ipê and virola (Virola sp.) are felled when they reach a dbh of 45 cm and 25 cm, respectively (José Baranek, pers. comm.). Trees with obvious defects, such as twisted trunks, are left as seed sources, while a few undesirable species, such as taxi preto (Tachigalia paniculata) and abiurana (various species of Chrysophyllum, Pouteria, Radlkoferela, Ecclinusa, and Micropholis), are ringed.
If the prime specimens are cut, the quality of the forest from the viewpoint of commercial timber is likely to decline as the inferior stock remains to reproduce (Whitten, Mustafa, and Henderson 1987: 441). From the genetic variation standpoint, it would probably make better sense to leave a random mixture of poor to excellent specimens. At the headwaters of some streams, 110 ha have been set aside as a forest reserve. If such reserves were larger, they could serve as important seed sources for re-stocking or genetic improvement in the future.
Another management technique is to cut all vines and lianas in a plot when trees are harvested, but the impact of such measures on pollinators and seed dispersal agents is unknown. In Sumatra, climbing plants are significant food sources for primates, such as orangutan and gibbons (Whitten et al. 1987: 481). It could be argued that timber companies are not in the business of managing forests for monkey populations, but at least the ecological implications of vine removal warrant further study. Whenever feasible, managed forests should serve as refuges for wildlife. Managed forest at CEMEX appears to be fulfilling this role at least partially, since jaguar cubs have been encountered by workers when preparing plots for harvesting. Another factor to consider is that vines may pump significant amounts of ground water to the canopy (Nepstad et al. 1991).
Skidders cause much less damage to remaining trees than do bulldozers, so CEMEX employs two skidders to remove logs from the forest. Skidders are equipped with large lyres rather than moving tracks and thus disturb the topsoil less than do bulldozers. The skidders drag logs to small clearings where they are cut into sections for loading on to trucks.
CEMEX began two reforestation/forest enrichment projects in 1989. Reforestation is being attempted in second growth, while enrichment planting with mahogany is being carried out in an adjacent patch of logged forest. By the end of 1992, some 200 ha were planted with a mixture of valuable timber trees. Second growth is slashed and mulched, while the larger trees are ringed. In the logged forest, par allel lines are cut through the semi-open forest and timber seedlings are planted at regular intervals. Mahogany is the most commonly planted tree (table 4.9), in part because it does not occur naturally in this part of Amazonia. Only a few of the mahogany seedlings have been attacked by Hypsipyla grandella, a moth larva that tunnels into the growing shoot, thereby retarding growth and provoking defects in the trunk. This pest is more likely to be a problem when mahogany is planted in monospecific stands.
Table 4.9 The annual planting of timber species species second-growth and logged forest at CEMEX, km 101 Santarém-Cuiabá, Pará
|Common name||Scientific name||Seedlings planted/yr|
Note: Smaller quantities of andiroba, tatajuba, jatobá (Hymenaea sp.), piquiá (Caryocar villosum), gumbeira, and virola are also being planted in second growth.
Although owning forest land provides some incentive for more sustainable logging practices, it remains to be seen how successful the management techniques employed by the sawmills in Para will be, and whether the land will eventually be converted to non-forest uses. A key issue in sustainable forest management for timber production is the duration between harvests. The longer it takes for the forest to regenerate commercially harvestable timber, the less likely it is that landowners will be interested in saving their forests. The owner of São João ranch near Paragominas may have to wait decades before another sizeable harvest of timber is possible in the remaining forest stand on his property. In the Philippines, for example, 30-45 years typically pass before forests are selectively logged again (Schmidt 1987). How short one can make the cutting cycles depends on a variety of factors, such as the proximity of desirable timber species remaining to re-seed logged areas, soil fertility, the degree of damage to seedlings and soil structure, and changes in marketing opportunities for hardwoods.
One of the greatest disincentives to managing forest for timber production in Amazonia and many other parts of tropical America is that other land uses are often more profitable (Kishor and Constantino 1993). The proliferation of pioneer highways and feeder roads in Amazonia during the past three decades has made it cheaper to obtain timber along the agricultural frontier rather than to manage forests. While it is still possible to gain access to mature forests and "cream" the valuable timber, few landholders will want to invest in sustainable harvesting of timber. Rather than open any new roads in Amazonia, efforts might be made to improve existing ones by repairing bridges and side-roads. Incentives are also needed to foster attempts to manage forests for timber and other products.
Few models for sustained management of tropical forests for timber production are available to guide policy makers in Amazonia (Perl et al. 1991; Westoby 1989: 37). Members of the International Tropical Timber Agreement (ITTA) have agreed that tropical timber should be sustainably harvested by the year 2000, whereas only 1 per cent is thought to be sustainably managed today. In 1991, a truck headed for the Belém port loaded with wood was stamped "Ecological Wood." A veritable industry could soon start, with organizations certifying that wood has been harvested "sustainably." Clever public relations cannot disguise the fact that the scientific underpinnings for forest management are wanting. Labels attesting to the sustainability of harvesting methods for a product may not mean much if there is not some independent review board for making such assertions. Monitoring the harvest of tropical timber to verify environmentally sound techniques will be costly.
For the time being, one can only grasp at a few cases that shed some light on the potential for harvesting timber from forests in humid tropics. In one part of Surinam, for example, selective logging with carefully planned skid trails and the poisoning of non-commercial trees can produce timber harvests of 20 m3 per hectare every two decades (Graaf 1982). Given the dispersed nature of highly desirable timber trees (Anderson 1987), sustained management of forests in Amazonia would appear to be a low-yield operation.
International markets could be developed for some of the lesser-known timber trees, but dealers like reliable supplies in order to cultivate a new product. Considerable research is needed on potential timber trees and rational harvesting methods that offer reasonable economic returns. Of the more than 700 promising timber species in Amazonian forests, only 10 species accounted for more than 60 per cent of the saw and veneer log production in the region during the 1980s (Anderson 1987).
The Yanesha Forestry Cooperative at Palcazu in the Peruvian Amazon could provide some useful insights into sustainable timber harvesting in tropical forests. With technical assistance from the Tropical Science Centre in San José, Costa Rica, the Peruvian Foundation for the Conservation of Nature (FPCN), and the World Wildlife Fund, the Yanesha clear-cut narrow strips from 20 to 40 metres wide in the forest. In order to minimize disturbance of the topsoil and damage to remaining trees and seedlings, the Yanesha use cattle to extract timber from their 75,000 ha reserve in the Palcazu valley. A 40-year rotation is envisaged for this pilot project (Earhart 1990). Financial assistance is provided by a variety of donors, including the World Wildlife Fund and the US Agency for International Development (Perl et al. 1991:13).
It would be premature to suggest that the Yanesha experience can serve as a model. Wood produced by such methods may be more expensive than from other timber suppliers. For the time being at least, the timber output from the Palcazu project is modest, destined mostly for artisans and local furniture makers. A contract to supply chemically treated poles for the state telephone company provides some additional income, but the entire operation is still subsidized. Furthermore, cattle pasture usually entails clearing forest, and the sawmill at the Yanesha mill is fuelled by diesel rather than waste wood. Yanesha lands are communally owned, thus making it easier to establish strips for harvesting. It could be difficult to arrange for strip harvesting on a checkerboard pattern of small, privately own lots with varying patterns of land clearance.
Start-up funds are usually necessary for pilot projects in forest management, but the acid test for sustainability is whether such ventures can be successfully weaned from external financial support. If "green" companies proliferate, or legislation restricts the importation of tropical timber harvested unsustainable, then natural forest management will have a better chance of succeeding. The Ecological Trading Company in the United Kingdom and Luthier Mercantile in California are customers for timber from the Yanesha Forestry Cooperative, but many more such companies will need to come forward to buy forest products obtained on an allegedly sustainable basis.
Sawmill linkages with other land-use systems
By-products from sawmills are used in other land-use systems. In the Santarém area, sawdust is given to farmers on both terra firma and the Amazon flood plain. The sawdust is employed to help conserve soil moisture and suppress weeds, rather than to supply nutrients.
Upland farmers mound sawdust around black pepper plants, while some vegetable growers on the Amazon flood plain scatter sawdust in tomato beds. In the Marabá area, scrap wood from some sawmills is converted into charcoal for COSIPAR, a pig-iron smelter. Sawmills benefit from this arrangement because they reduce their waste disposal problem.
Charcoal production for pig-iron smelting
Charcoal production has emerged as an important land-use activity in the Marabá area within the past decade. Furthermore, the preparation of charcoal has close linkages with other land uses, and it has the potential to alter landscapes dramatically. In most areas of Amazonia, charcoal is used extensively for cooking, in both urban and rural areas.
In order to generate more domestic employment, plans were drawn up to smelt some of the iron ore from Carajás along the railroad to Itaqui. This 900 km railroad was built in the early 1980s to export minerals, particularly iron ore and manganese, to a deep-water port near São Luis in Maranhão. All told, some 23 pig-iron smelters were planned for construction along the railroad, with charcoal as the main source of energy. In addition, charcoal is used in the reduction process. Natural vegetation was envisaged as the main source of charcoal, at least in the initial stages of production.
The spectre of 23 pig-iron smelters concentrated along a relatively thin strip of south-east Amazonia immediately sparked concern about deforestation and potentially adverse impacts on other land-use systems, such as swidden farming by small-scale colonists and indigenous groups. A single pig-iron smelter would require as much as 100,000 ha of forest for sustainable charcoal production, based on the annual production of a typical pig-iron smelter in the region and a charcoal yield of 30 tons/ha in forest.
Pig-iron smelters planned along the Carajás-Itaqui railroad could result in the destruction of 1,500 km of forest each year (Anderson 1990a). On a small scale, the harvesting of native forests for charcoal makes sense, since production costs are low. On a large industrial scale, however, the vast areas of forest needed to sustain harvesting preclude other potentially more productive uses of the landscape and could lead to serious ecological degradation. In the case of pig-iron smelters along the Carajas-Itaqui railroad, for example, some of the densest groves of Brazil nut trees would be lost. At current market prices for pig-iron, plantations of fast-growing exotics, such as eucalyptus, would not be economically viable.
How much forest will eventually be cleared to satisfy the pig smelters is unclear. Iron smelting destroyed much of the oak woodlands of Sussex in England during the Middle Ages, some of which subsequently grew back (Perlin 1989: 168, 177, 189). Earlier, the Romans had cleared much of the forests from south-eastern England for agriculture and to reduce cover for hostile groups. The loss of plant and animal resources will be much greater with the disappearance of forest along the Carajas-Itaqui railroad should all the planned pig-iron smelters come on line.
Thus far, only four pig-iron smelters have been built along the railroad, two on the outskirts of Marabá and the other two further east at Acailandia. Only one of the pig-iron smelters near Marabá was operating in 1992. The three pig-iron smelters currently on line have not accelerated deforestation since the wood is coming from sawmills and from branches and trunks left in fields by swidden farmers (World Bank 1992: 30).
How many pig-iron smelters will be built is uncertain. Brazil's desire to process some of the iron ore to generate jobs is commendable, but it seems unlikely that the projected production goal of 16 million tons of pig iron a year will be reached by 2010 (Treece 1989). Even if electricity from the Tucurui dam provides much of the energy for melting the iron ore, charcoal is still needed for the reduction process.
Uncertainties about whether or not the forest would be managed on a rational basis provoked fears that large blocks of woodland would perish, thereby undercutting the subsistence base of numerous farmers and compromising future options for development and conservation. For a variety of reasons, including a deep recession and heightened concerns about the environmental and social costs of large-scale charcoal production from the Amazon rain forest, only a handful of pigiron smelters are currently functioning.
Before exploring the social and environmental implications of pigiron smelters and highlighting some pertinent research questions, a brief description of current charcoal production can provide insights into interactions with other land-use systems. Charcoal-makers are at the lowest end of the socio-economic ladder, sharing this tenuous position in society with itinerant miners. Fishermen and sharecroppers are next on the societal ladder. Still, movement between these "lower" strata is brisk and frequent, as people move on to other opportunities and thus leave one form of employment for another. At least some of the charcoal-makers come from Minas Gerais, a state where cerrado trees and eucalyptus plantations are converted to charcoal for the steel industry. Other charcoal-makers are from Pará and Maranhão, and have been engaged previously in a range of activities such as farming and fishing.
Charcoal-makers own no land (fig. 4.6). They work on the lots and ranches of others, and pay landlords a percentage of the value of the charcoal produced. In turn, landlords allow the charcoal-makers to live temporarily on their land, and to collect wood left over after burning forest or old second growth. Landowners often provide tangible assistance, such as a bullock and cart, power saws, and bricks to build the ovens. At Sitio Sapecado, a 90 ha property along a side-road leading from km 35 of the PA 150 highway south of Marabá 10 ovens are in production. Charcoal-makers are generally organized into groups, which range in size depending on the number of ovens on the property; a work group can range from as few as 2 men to 20 or more. Families who accompany charcoal-makers build make-shift homes on the property, but generally do not grow any crops.
Each dome-shaped oven is designed to produce 1.5 tons of charcoal a week. Wood, cut into 1 to 1.5 metre lengths, is stacked inside the oven and then allowed to burn for two days. The temperature of the burn is controlled by blocking some of the holes in the side and bottom of the oven. After the charcoal has formed, the oven cools for three days before the charcoal is taken out. Large trucks pick up the charcoal and take it to COSIPAR, which began smelting in 1986. COSIPAR pays US$9/ton for charcoal at the "farm gate." Another pig-iron smelter in Marabá SIMAR, is apparently slated to come back on line in the near future; if this occurs, greater competition may boost the price paid for charcoal.
Charcoal production interacts with three other main land uses in the Marabá area: swidden agriculture, ranching, and sawmills. In the first, charcoal producers remove branches and the smaller logs remaining after fields are burned for subsistence crops such as rice, maize, beans, and manioc. In this regard the removal of the wood could reduce the amount of nutrients and organic matter entering agro-ecosystems. Furthermore, scattered logs and branches help check soil erosion in swidden fields, which is particularly important in the case of steep slopes or plots cleared on sandy soils. In the case of ranching, landholders employ charcoal-makers to help defray the cost of clearing land. In exchange for preparing as much charcoal as they can, the temporary workers agree to plant pasture seed at the appropriate time, usually as the rains are beginning. Increasingly, the rancher or farmer supplies the grass seed, usually Brachiaria brizantha. This process is well developed in other parts of the humid tropics in Latin America, such as in the highlands of Costa Rica. Sawmills appear to be a significant source of wood for charcoal-making for use in pig-iron smelting, but hard data on the relative contribution of wood from the three land-use systems for charcoal production are lacking. One point is clear, however: forest is not currently being cut down solely for charcoal production.
Silviculture for charcoal production
In response to the requirements of IBAMA that consumers of wood must either manage forest on a sustainable basis or replant, COSIPAR has recently established a project to plant eucalyptus to supply the charcoal ovens. As of November 1992, COSIPAR had planted 400 ha of eucalyptus, mainly Eucalyptus urophylla, along a side-road leading from km 35 of the PA 150 highway south of Marabá A further 800 ha of eucalyptus was slated for planting in 1993. All plantings are in second growth. Three fertilizer treatments of 65 g of triple super phosphate are applied to the trees according to the following schedule: when the seedlings are planted; at 45 days; and then again three months after planting.
It is unlikely that eucalyptus plantings for charcoal will be a viable proposition in Amazonia for the near future. At Jari, over 20,000 ha of eucalyptus have been planted for pulp production, a relatively high-value product. The abundance of forest and old second growth in the Marabá area, as well as the high cost of labour and inputs, undercut the economic viability of silviculture for charcoal. When the pioneer front has moved on and naturally occurring wood becomes more scarce, silviculture for biomass fuel might become a more attractive investment.
Two ways to help make biomass plantations more promising are to select superior germ plasm and to incorporate other crops and/or livestock. A few hectares of the COSIPAR plantation are intercropped with pasture, a common practice in Minas Gerais where most of the natural woodlands have long since been cleared. Nevertheless, substantial subsidies would likely be needed to accelerate eucalyptus plantings for charcoal production in the twentieth century in the Marabá area.
Perhaps natural regeneration could be managed by the addition of some quick-growing nitrogen-fixing trees, such as species of Gliricidia. If ashes from smelters are not returned to the land, fertilizers will eventually be needed. The economics and ecological implications of large-scale charcoal production in Amazonia are currently being investigated by CVRD in collaboration with scientists from Brazil and abroad. Large-scale monocultures for charcoal production are unlikely to become economically attractive ventures in the near term; perhaps managed second growth could satisfy some of the market for charcoal.
Another possibility would be small-scale agro-forestry, in which farmers grow fast-growing trees for charcoal alongside food and other cash crops (Shaeff1990: 95). An advantage of such an agroforestry approach is that it would involve many of the small farmers in the region and could be incorporated into existing farming systems. Farmers would need technical support for such a venture, however, and research would be needed on appropriate trees. Agro-forestry systems are unlikely, however, to supply sufficient charcoal for 22 pigiron smelters, let alone many of the other enterprises in the Marabá area that draw on charcoal supplies. Some 4 million metric tons of charcoal would be needed annually to supply the planned pigiron smelters, cement plants, and other industries during the 1990s (Shaeff 1990: 7).
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