Brazil Case Study
Although Brazil covers half the land area of South America, its reserves of oil and coal
are relatively small, and Brazilian coal is of relatively low quality. Brazil's search for alternative
energy sources began with the passage of the Forest Code of 1965 and Public Law 5106 in 1966,
which provided incentives for the forest products sector. As a result, the area of forest plantation
increased from 470,000 ha before the incentives to 6.5 million ha in 1993. Currently, a large
portion of the charcoal used in steel production and nearly all feedstocks used in the country’s
pulp and paper industry come from these plantations. Eucalyptus plantations represent 51% of
the planted area; pines (Pinus species) account for another 32%. A native nitrogen fixing tree
species, bracatinga (Mimosa scabrella) is used extensively in wood energy plantations in
southern Brazil. The scale of short-rotation forest plantations in Brazil dwarfs that of other
countries. These plantations provide 39% of the wood used for industrial purposes in Brazil.
Fiscal incentives were important factors in developing Brazil's pulp and paper industry
and charcoal-based iron and steel industry. The cement and composite board industries are also
large consumers of plantation-grown wood products. The growing pulp and paper industry,
however, was probably the most significant factor that promoted development of large eucalypt
plantations in the 1970s. Brazil has become a net exporter of wood products from short-rotation
trees, including pulp and paper, plywood, hardboard, and pine lumber. Forest products account
for 5.6% of Brazil's Gross Domestic Product (GDP), 4% of Brazilian exports and approximately
2.5 million jobs in rural areas.
Farm forestry and agroforestry (intercropping of trees and food crops), has become an
increasingly important element of Brazil's forestry experience. Today farm forestry accounts for
up to 20% of the total plantation area, with some forestry companies expecting to raise this to
50%. In the mid-1980s, federal tax incentives were removed in response to environmentalists'
objections to large plantations. At that time, forestry companies began contracting with private
farmers to expand wood supplies. A forestry company would provide the material (seedlings,
fertilizers, herbicides) and technical know-how for establishing the trees and agree to buy some
or all of the first harvest at an arranged price that would incorporate repayment for the initial
inputs and services.
Farmers have cooperated willingly because the trees provide added income, a sure
market, productive use of marginal land, and more wood for on-farm use. Forestry companies
like farm forestry because it involves lower capital requirements (i.e., lower establishment costs),
no direct tending or maintenance costs, and reduced transport costs, as farms are usually close to
mills.
Site and Species Selection
When the incentives were introduced, planners had no ecological zoning or no
comprehensive body of scientific work to help them select the best species for each region and
site. Plantations were established in savanna-like regions in the central-west and southeast,
primarily because of low land prices there. In these areas, the climate, low annual rainfall and
five- to seven-month dry season were unsuitable for Eucalyptus grandis and E. saligna, the
species planted. These conditions, together with the distance of sites from potential markets,
resulted in major failures. In some cases, plantations were never well established because of
limited groundwater availability or the presence of subsurface gravel layers that roots could not
penetrate. Such failures led to greater recognition of the importance of the site characteristics of
existing vegetation, slope, chemical and physical soil characteristics, availability of water and
energy, and distance from consumers.
In the early years, also, native forest ecosystems were cleared and burned to make room
for "reforestation" plantations. When that was banned, plantations were established on
abandoned or degraded agricultural lands or on land previously occupied by eucalypt stands.
Rising land prices in industrialized regions further reduced opportunities for expanding
plantation area near existing forestry mills. Given these restrictions, companies increasingly
promoted higher productivity through genetic improvement and careful soil management.
In Brazil, the most widespread commercial eucalyptus species is E. grandis. The national
and state governments and forestry companies also con-duct genetic improvement programs for
E. saligna, E. urophylla, E. camaldulensis, and E. citriodora. Controlled hybridization, cloning
and micropropagation have been used to produce homogeneous stands that provide high
productivity, natural resistance to pests and diseases, and uniform raw material. E. camaldulensis
has become the preferred agroforestry species because of its narrower canopy, which minimizes
shading of nearby food crops, with beans the preferred intercrop.
Bracatinga, a native nitrogen-fixing tree, has become a major plantation species in the
cold highlands of southern Brazil. Although it shows lower yields than eucalyptus (about 13
steres/ha/year on a seven-year rotation), many farmers prefer bracatinga because it can be grown
at much lower cost, requiring no fertilization, tending or control of leaf-cutting ants (an expense
incurred with eucalypts). Bracatinga stands are generally planted at densities approaching 20,000
seedlings/ha and later thinned to 3,000-4,000 seedlings/ha. By harvest time, bracatinga seeds are
naturally incorporated into the soil, with no need for replanting. Bracatinga has been collected
locally by provenances and, like eucalyptus, has become the subject of genetic improvement
trials.
Plantation Establishment, Tending and Protection
Plantations have been established from vegetatively propagated clonal "seedlings" grown
in dibble tubes filled with vermiculite or a mixture of vermiculite, compost, and ground charcoal.
The nursery process for eucalyptus requires 70-80 days, with seedlings spending the first half of
the nursery period in shade, the second half in the sun. Most planting is done by hand.
Early operations employed harrowing, plowing and furrowing without regard to slope or
runoff direction, causing an enormous amount of erosion. Such unsustainable site preparation
was abandoned in favor of cultivation techniques that minimize soil and nutrient loss through the
use of herbicides, followed by furrowing along topographic contours.
Short-rotation coppice plantations generally use spacings of 3 m x 3 m (1,100 plants/ha)
or 3 m x 1.5 m (2,200 plants/ha). The early fiscal incentives favored denser plantations, but many
with densities of 5,000-10,000 trees/ha failed due to high mortality, small final diameter, and an
excessive proportion of bark to wood. Brazilian experience indicates that wider spacings lead to
greater mean annual increment growth, reduced wind damage, and permit easier harvesting,
weed control, and intercropping of agricultural crops. Spacing is adjusted to produce trees of a
specified diameter at harvest, given site quality, plant genetics and rotation period.
Each seedling normally receives an initial 120 g of N-P-K fertilizer. Early operations
applied a standard fertilizer formulation to sites; later companies developed specific formulations
for each site, species, hybrid and clone.
In eucalyptus plantations, weed control is performed twice a year, and is considered
critical until canopy closure, usually after the first two years. In early Brazilian plantations,
weeds were controlled by discing between rows and hoeing within rows. Discing, however,
caused erosion (since rows were usually oriented downslope) and cut the trees' surface roots,
retarding growth and sometimes causing death. Later, plantation managers adopted methods that
did not disturb the ground surface, such as herbicides (applied just before planting and again at
4-8 months) and mowing. Research found that sheep and cattle could be used for weed control,
and that intercropping with agricultural crops could eliminate the need for tending operations
during the first year.
Resistant clones, hybrids and species are planted to control fungal diseases. Leaf-cutter
insects pose a more serious threat: when established, they can destroy a young plantation in a
few days. Plantations require careful monitoring to detect colonies at an early stage. In 1992,
dodecachlor-based baits were banned, replaced by sulfluramid-based bait. Other local insects,
particularly the families Lepidoptera and Coleoptera, have caused problems for some eucalypts.
Control initially involved pesticides, but environmental damage, growing insect
resistance to pesticides and their high cost limited their use and effectiveness. Insect problems
were partially alleviated through better site-species matching and silvicultural practices such as
pruning. A major breakthrough occurred with the recognition of biological controls, which now
provide the main form of insect control. For example, many insects are controlled by intermixing
native vegetation with the exotic eucalypts, which helps maintain local bird populations.
Growth, Production, and Harvest
Eucalyptus harvesting has become increasingly mechanized, with felling usually done
with chain saws. An average operator cuts 120 trees/day. Crowns are lopped off; trees can be cut
into sections or left whole, depending on the equipment used to move trees to the landing.
Loading is done with grapple loaders. Nearly 70% of transport to mills is by truck, the remainder
by rail. The haul distance averages 70 km one way, with maximum hauls in the range of 200-300
km. Transport fuel expense remains a major concern to forest companies.
Bracatinga is mainly grown on smaller farms, and harvested by axe. Logs are cut into
0.8-1.2 m lengths with a minimum 4 cm diameter. Horse carriers or tractor trucks transport logs
to the roadside. Logs typically are sold from the roadside.
Productivity of short-rotation, large-scale eucalyptus plantations in Brazil has increased
dramatically over the past two decades. In some areas, annual yields rose from 35 steres/ha/year
in 1970 to 70 steres/ha/year in 1993. This resulted from a substantial research effort, particularly
in genetics and biotechnology, reinforced by better silviculture and management practices.
Yields from farm forestry remain somewhat lower (with lower establishment costs).
The costs of growing one hectare of eucalyptus on a seven-year rotation vary widely
depending on the region, soil fertility, species, and technology. In 1989, logging and transport
costs, for example, varied with region and terrain from 51%-70% of total delivered wood costs.
Because the planting and cultural costs of bracatinga were lower, logging and transport costs
could comprise up to 93% of total operational costs.
After harvest, logging slash is burned or used for energy. If the plantation employs
coppicing for regeneration, the area is disced and broadcast fertilized. Stump sprouts normally
appear within 2-3 weeks. In cases where the stand is replanted, stumps are removed or covered
with soil, and seedlings planted in the rows between stumps.
In the 1970s and 1980s, yields declined for eucalyptus stands established by coppicing.
Contributing factors included use of inappropriate sites and provenances, large genetic variation
of planting materials, high incidence of canker and leaf cutter attacks, and the damage to coppice
stumps caused by harvesting. Most of these problems were later addressed.
Lower costs of coppice establishment (about 10% of planting costs) partially offset the
reductions in yields (approximately 15% for the first coppice and 30% for the second). Due to
the rapid improvement of genetic stock, however, Brazilian companies have shifted to renewing
stands after the first harvest.
Observations
Brazil's experience indicates that success requires direct links between plantation
establishment and an existing or planned end user. Success also requires a fully funded
government oversight organization and educational and research institutions.
As a result of considerable pressure from environmental groups to limit further eucalypt
plantation establishment, national, state and municipal forest legislation in Brazil is becoming
more restrictive. Critics of monocultural eucalyptus plantations maintain that these plantings
reduce biodiversity, encourage soil erosion, reduce soil nutrients, lower local water table levels
and compete with food crop production.
To minimize the environmental impact of eucalyptus plantations, Brazilian researchers
proposed the following actions:
• Use ecological zoning for better species selection and management.
• Augment biodiversity through increased use of agroforestry systems.
• Conduct research on the ecology of native forest species that may substitute for
eucalyptus.
• Implement more biological (vs. pesticide-based) pest control.
• Reduce the use of mechanized techniques on steep slopes.
• Institutionalize a process of environmental impact assessment.
As a result, forest companies have moved toward sustainable management of other forest
resources (including water, air quality, soil, wildlife, recreational and scenic values) in addition
to wood products. Many of the large companies now include strips or blocks of native vegetation
within plantations.
Tree farmer programs, which bring small farmers into the companies' supply planning
and operations, are becoming more important supply sources. These small farmer programs are
seen as promoting rural economic development, reducing migration to urban areas, and limiting
the concentration of land ownership by large forest companies. The companies are also
conducting agroforestry research to gain the biological, technical and economic information
needed for such programs. The companies have improved their public image through
agroforestry and local education programs, and donations toward preservation of endangered
ecosystems.
There has always been intense public scrutiny of commercial bracatinga harvests.
Harvesting is permitted only for mature stands and only on a sustained-yield basis. Widespread
clearcutting of bracatinga was banned to reduce soil erosion and preserve water tables. The
policy has stabilized fuelwood supply during a period of rising demand. This has helped raise the
real price of bracatinga and the income of thousands of small farmers.