Between May 2000 and August 2005, Brazil lost more than 132,000 square miles of forest... an area larger than Greece.
And since 1970, well over 323,000 square miles of Amazon Tropical Rainforest has been destroyed. Why is Brazil losing so much forest? What can be done to slow deforestation?
In many tropical countries, the majority of deforestation results from the actions of poor subsistence cultivators. However, in Brazil, only about one-third of recent deforestation can be linked to "shifted" cultivators. A large portion of deforestation in Brazil can be attributed to land clearing for pastureland by commercial and speculative interests, misguided government policies, inappropriate World Bank projects, and a commercial exploitation of forest resources. For effective action, it is imperative that these issues be addressed. Focusing solely on the promotion of sustainable use by local people would neglect the most important forces behind the deforestation in Brazil.
Brazilian deforestation is strongly correlated to the economic health of the country. The decline in deforestation from 1998 to 1991, nicely matched the economic slowdown during the same period, while the rocketing rate of deforestation from 1993 to 1998, paralleld Brazil's period of rapid economic growth. During lean times, ranchers and the developers do not have the cash to rapidly expand their pasturelands and operations, while the government lacks funds to sponsor highways and colonization programs and grant tax breaks and subsidies to the forest exploiters.
A relative small percentage of large landowners clear vast sections of the Amazon for cattle pastureland. Large tracts of forest are cleared and sometimes planted with African savanna grasses for cattle feeding. In many cases, especially during periods of high inflation, land is simply cleared for investment purposes. When pastureland prices exceed forest land prices (a condition made possible by tax incentives that favor pasture-land over natural forest), forest clearing is a good hedge against inflation.
Such favorable taxation policies, combined with government subsidized agriculture and colonization programs, encourage the destruction of the Amazon. The practice of low taxes on income derived from agriculture and tax rates that favor pasture over forest, overvalues agriculture and pastureland and makes it profitable to convert natural forest for these purposes when it normally would not be so.
Historically, hydroelectric projects have flooded vast areas of Amazon rainforests. The Balbina dam flooded some 920 square miles of rainforest when it was completed. Philip Fearnside, a leading expert on the Amazon calcuated, that the first three years of its existence, the Balbina Reservoir emitted 23,750,000 tons of carbon dioxide and 140,000 tons of methane, both potent greenhouse gases which contribute to global climate change.
Mining has impacted some parts of the Amazon Basin. During the 1980s, over 100,000 prospectors invaded the state of Para when a large gold deposit was discovered, while wildcat miners are still active in the state of Roraima near the Venezuelan border. Typically, miners clear forest for building material, fuelwood collection, and subsistence agriculture.
Currency Devaluation: The devaluation of the Brazilian Real against the Dollar effectively doulbed the price of beef in reals and created an incentive for ranchers to expand their pasturelands at the expense of the rainforest. The weakness of the real also made Brazilian beef more competitive on the world market. [CIFOR]
Control Over Foot-and-Mouth Disease: The eradication of foot-and-mouth disease in much of Brazil has increased price and demand for Brazilian beef.
Infrastructure: Road construction gives developers and ranchers access to previousley inaccessible forest lands in the Amazon. Infrastructure improvments can reduce the costs of shipping and packing beef.
Interest Rates: Rainforest lands are often used for land speculation purposes. When real pastureland prices exceed real forest land prices, land clearing is a good hedge against inflation. At times of high inflation, the appreciation of cattle prices and the stream of services (milk) they provide may outpace the interest rate earned on money left in the bank.
Land Tenure Laws: In Brazil, colonists and developers can gain title to Amazon lands by simply clearing forest land and placing a few head of cattle on the land. As an additional benefit, cattle are a low-risk investment relative to cash crops which are subject to wild price swings and pest infestations. Essentially, cattle are a vehicle for land ownership in the Amazon.
A significant amount of deforestation is caused by the subsistence activities of poor farmers who are encouraged to settle on forest lands by government land policies. In Brazil, each squatter acquires the right to continue using a piece of land by living on a plot of unclaimed public land (no matter how marginal the land) and "using" it for at least one year and a day. After five years the squatter acquires ownership and hence the right to sell the land. Up until at least the mid-1990s, this system was worsened by the government policy that allowed each claimant to gain title for an amount of land up to three times the amount of forest cleared.
Poor farmers use fire for clearing land and every year satellite images pick up tens of thousands of fires burning across the Amazon. Typically, understory shrubbery is cleared and then the forest trees are cut. The area is left to dry out for a few months and then burned. The land is then planted with crops like bananas, palms, manioc, maize or rice. After a year or two, the productivity of the soil declines and the transient farmers press a little deeper and clear-cut new forest for more short-term agriculture land. The old, now infertile fields are used for small-scale cattle grazing or just left for waste.
Between 1995 and 1998, the government granted land in the Amazon to roughly 150,000 families. Forty-eight percent of forest loss in 1995 was in areas under 125 acres in size, suggesting that both loggers and peasants are significant contributors to deforestation.
Strange things are happining in the lush Amazonian rainforests and the rising levels of carbon dioxide could be the cause. Even in pristine rain-forests unaffected by human activities such as logging or burning, researchers have noticed dramatic differences in growth patterns of trees over the last twenty years.
That could distort the forest's fragile balance affecting rare plant and animal species. "The changes in Amazonian forests really jump out at you," said lead author Dr. William Laurance, of the Smithsonian Tropical Research Institute in the Republic of Panama and the National Institute for Amazonian Research in Manaus, Brazil. "It's a little scary to realize seemingly pristine forests can change so quickly and dramatically."
The researchers marked out 18 plots of 2.5 acres in central Amazonia and tagged nearly 13,700 trees with a trunk diameter fo more than 10 centimetres. Then they monitored the growth and each species' population over the next 20 years.
Of the 115 most common species, 27 showed spectacular changes in population density and basal area, the amount of land occupied by the trunk of that species, a reliable indicator of biomass. Thirteen species gained in population density and 14 declined; 14 species occupied a greater portion of the land, while 13 species retreated.
The big winners in the fight were spindly canopy trees and shrubs, such as the manbarklak, sclerobium and parkia, which are fast growing and whose wood is of light density.
The losers were slow-growing, dense tropical hardwoods, such as the croton and oenocarpus that live in the dark forest interior.
Their decline is significant, because these slow growers are by far the biggest absorbers of carbon. They are the species that give the Amazon its reputation as a vital "Sink" that can suck up CO2. Levels of CO2 have risen by 30% in the past 200 years because of the emissions from vehicles and industry, and rapid forest burning, particularly in the tropics. Much of the increase in CO2, which plants use from the air as a carbon source for photosynthesis, has occured since 1960.
The scientists suspect the rising CO2 levels are fertlilzing the rainforests and increasing competition for light, water and nutrients in the soil. So the big fast-growing trees have an advantage and are outpacing the smaller ones. The researchers believe the odd change in growth patterns could also be a signal for an overall change in rainforest ecology. The authors looked at other factors that could have driven the change in tree composition, such as recovery from human disturbance, vulnerability of some trees to the El Nino phenomenon, or long-term change in rainfall patterns.
But they believed the most likely cause was rising atmospheric CO2 levels.
The total biomass of ants in tropical rainforests exceeds that of mammals, and it now seems herbivorous ants may play a huge role in the carbon economy of rainforests. Until now, it had been assumed that the ants were predators or scavengers, eating other insects. But in the rainforests of Peru and an island of Borneo, U.S. and Malaysian ecologists have found that ants get essential nitrogen from the liquids exuded by plants and sap-sucking insects, not from chewing leaves or preying on other animals.
The research team, headed by Prof. Diane Davidson from the University of Utah, used an ingenious method to track ant diets. They measured the ratio of a nitrogen isotope, which changes the higher an organism is up the food chain.
They found many rainforest ants have the same ratios of nitrogen isotopes as leaf-chewing and sap-sucking insects, including plants themselves. They also eat pollen, fungi and its spores, and microscopic flora living on leaves.
The discovery means that anys may be indirectly responsible for using far more herbivorous nitrogen and carbon in tropical rainforests than previously believed. Ants are the ecologically dominant animals of the tropical rainforests, conprising up to 94% of arthropods and 86% of the biomass in samples from the canopy. About one-third of tropical trees, shrubs, and vines produce nectar from small glands outside the flowers, on leaves and stems, to attract ants and perhaps spiders. Also, sap-feeding insects such as aphids produce "Honetdew" rich in carbohydrates and with a higher concentration of nitrogen that the sap.
Many tree-dwelling ants 'tend' the nectaries and the insects to 'harvest' the liquids as food. It's a trade-off that works well for all... in return for the investment by the plants in producing nectar and supporting sap-suckers, the ants defend the plants and insects from leaf-chewers and predators.
In the early days of Amazon exploration, collecting specimens helped catalog the variety and number of plants and animals. This gentlemanly past-time's purpose was to advance knowledge. However, the practice also sowed the seeds fo destruction. As the rainforests wonders were unveiled, more and more people wanted to include specimens in private collections, simply for the status of owning exotic plants and animals.
So the rush was on. Millions upon millions of plants, insects and other specimens were collected for sale to avid enthusiasts in North America, Europe and Asia. There is no way we can know the total numbers, but some orchids and butterflies became particularly rare, perhaps extinct. So they became more desirable, their price went up, and the incentive to collect them became even greater.
Spiralling demand pushed some species to the brink of extinction. Only enforcement of strict export laws curtailed this way of life. Today... commercial collecting still continues, although mostly illegal.
Animals are widely hunted in the Amazon and some, like the tapir and peccaries are hunted for food. On this small scale, hunting has no longterm effect. Other animals, notably caimans, wild cats and the large snakes are killed for their skins. There are few laws against hunting and these tend to be poorly enforced.
Local people see the forest as a source of income so ultimately, it is the buyers of wild animal products who must be deterred. Excessive hunting can disrupt the ecological balance, especially when top predators are removed, the prey species can multiply uncontrollably. In some cases, hunting can push a species toward extinction. Sometimes the animal is hunted for sale as a pet or for research, and on a large scale this can be as devastating as animals hunted for their skins.
Road building can have a tradgic effect on the rainforests integrity as an ecosystem. One effect is to disrupt the natural migration of the animals. Some birds for example, will not cross open spaces. A road is an effective barrier, hemming them in and preventing them moving to a new food source or nesting area.
Roads also assist in the spread of non-native weeds and pest animals, which can hitch a ride on cars and trucks. These species can out-compete local organisms. However, the worst effect of road building is to provide access to people for settlement. Once a road is built, the people follow...
The stage is set for the degradation of forest due to the settlement and subsequent unbanization.
The Amazon itself is sparsely populated, about 10 million people inhabit an area almost the size of the United States. But the fragile habitat is easily disrupted by the activities of settlers. As the population of Amazon countries continues to increase at a rapid rate, the people move into the rainforest lowland, having a dramatic effect on the ecosystem. The local agriculture based on traditional practices is not harmful, but when the land is cleared for grazing and ranching, the effect is devastating.
Urbanization is also damaging. Besides forest clearing, pollution affects the habitat well beyond the boundaries of cities and towns. New satellite imagery clearly illustrates this damage. The desire for what is perceived to be a better life is one of the motives driving migration into the large cities.
People in the remote villages dream of a happier life in the city. When exposed to the dominant westernized culture, they realize something is missing... an abundance of material goods. Most of the village people do not have luxury goods such as televisions, computers, CD players or labor-saving devices.
The Amazon Basin spans South America and contains 40% of the world's remaining tropical forest. But every year more and more is being cut down. Last year, 2007, about 25,500 square miles of forest were felled. So far, the beginning of this year it seems even more is going up in flames. As environmentalists call for action, the Brazilian Government is attempting to curb the deforestation. But why is the Amazon Rainforest so special?
When the rains have fallen, the river rises by up to fifteen feet. Biodiversity is a word often associated with the Amazon. The forest contains a fifth of all the known plants on the Earth.
It is home to 2.5 million insects and 75,000 types of tree. There are about 90,000 living plants in one square mile. .
"It's the most biologically diverse real estate on the planet," says Dr. William Laurance, from the Smithsonian Institution in the United States, who has been studying tropical forests for about 20 years. "One biologist found more ants in one tree in the central Amazon than occurs in the whole country of Great Brittain." The forest is also believed to contain thousands of plants and insects that have still not been discovered, let alone studied by scientists.
Many pharmaceutical drugs derive from tropical rainforests. "Biochemists don't really create new compounds," says William Laurance, "They use the millions of years of evolutionary innovation that has occured in tropical rainforests, in which plants have had to evolve incerdible compounds to defend themselves fron insects and other organisms that are trying to eat them."
What worries people like Laurance is, that this pharmaceutical store cupboard is being destroyed. What about the effect on the global climate?
It's almost a cliche to describe the Amazon Forest as "The Lungs of the World," with its image of trees discharging oxygen into the atmosphere. However, it is now believed that during the night, the Amazon forest uses up most of the oxygen it produces during the day.
So what will the impact on the climate change if the Amazon continues to be cut down?
The Brazilian Institute of Space Research (INPE) monotors the destruction of the Amazon forest using satellite imagery. The big question is:
Is burning, to clear the forest the main source of Brazil's greenhouse gas emissions?
"The rains in the Amazon are very important for the atmosphere, for the circulation, for the winds all over the world. So a change in the rainfal patterns in the Amazon might impact rainfall patterns in remote areas of the planet. We know that the potential for affecting distant regions exist."
Since the earliest adventurers explored the Amazon Valley, their quest has been for its treasures... minerals, oil, animal skins, precious stones and metals, just to name a few. At times, they have succeeded. Gold, Emeralds, Petroleum and other raw materials so important to Western civilization have been exported from this vast region.
However, by "Taming" the forest and extracting its wealth, biological diversity has become the victim. Gold miners have polluted the Amazon and its tributaries with their Mercury and other chemicals; the search for iron and aluminum has destroyed huge areas of wilderness, converting verdant habitats to wasteland; and industrial ventures have turned millions of acres of pristine rainforest to desert-like habitat... all in the name of prosperity and economic return.
The richest treasure of the Amazon's biological diversity has been ignored. Millions of species of insects, animals, plants, and other organisms that inhabit this tropical wilderness are of extraordinary value to the indigenous communities and colonists that inhabit the region.
From the botanist's perspective, these lands are among the richest and most diverse forests on the planet. Botanist Alwyn Gentry found nearly 300 different species of trees growing on one-hectare plots he studied in the Peruvian Amazon. These plants were trees with a trunk diameter greater than 10 inches.
Among these "Green Treasures" are a wealth of plants that hold great promise for wider utilization. Indigenous and other local people presently utilize many of these species, and some have been introduced to agriculture elsewhere in the tropics. Some species possess specific advantages for cultivation, for example:
The ability to grow under harsh conditions, with minimal care, or have superior content of quality of oils, proteins, drugs, insecticides, waxes, or other products of importance. Without such a verdant and diverse flora, the ability of humans to survive and flourish in the Amazon Valley would have been impossible.
Astrocaryum aculeatum Meyer
A. murumuru Mart
A. vulgare Mart
Regional names: 'Murumuru'; 'Tucuma'
This group of palms, with characteristic heavily spined trunks, grow to 20m tall and are found commonly in many areas of the lowland Amazon.
They grow in both moist and dry habitats, e.g. in areas that remain uninundated during the rainy season, as well as along rivers. The fruits of these palms provide edible oil, and palm hearts can be obtained from the meristem.
One study of Astrocaryum vulgare reported that the fruit contained 3.5% protein, 19.1% carbohydrate and 16.6% fat.
In addition, the Vitamin A content was found to be a remarkable 50,000 i.u. per 100 grams of pulp, three times higher than that of the carrot. The oil derived from this plant is chemically similar to coconut oil.
Local people steam the fruits and eat them, or crack open the young fruits to drink the clear, sweet liquid inside. Fiber is also extracted from the leaves of Astrocaryum and used to make hammocks, baskets, hats and other necessities of Amazonian life. In the days of wind powered ocean going ships, voyages were made possible by the sails and masts lashed together with rope woven from Astrocaryum fiber, resistant to the rot and damage caused by long months at sea.
Bactris gasipaes H.B.& K.
Regional names: 'Cachipay (Colombia); 'Pifuayo' (Peru); 'Pupunha' (Brazil) 'Tembe' (Bolivia)
In English, this species is known as the "Peach Palm" and growes in clusters of several trunks, each reaching to 20m tall. The leaves, to 2m long, are variably spined with ferocious 10cm long needles. Each palm can yield up to a dozen fruit bunches annually. The fruits are orange to red on the exterior and inside contain a yellowish, mealy flesh surrounding a hard seed. The flesh, upon boiling for an hour or more in salty water, has been described as similar between a chestnut and potato in flavor but more palatable then either one. This palm is an extremely valuable plant, providing food to indigenous peoples who plant it wherever they live.
Indeed, when a group of these palms is found in the forest, it is a clear indication that a house once occupied the site. Many different forms of peach palm have been selected and domesticated by indigenous people, resulting in a broad range of colors, oil content, taste, fruit size and shape.
In recent times, the plant has been domesticated for the production of palm hearts in plantations in Costa Rica and Brazil, where it is now an agriculture crop. The "Heart" (apical meristem) is canned in a preservative for local consumption and export.
Oenocarpus bataua (Mart.) Burret
Local names: 'Majo' (Bolivia); 'Milpesos', 'Pataua' (Brazil); 'Seje' (Colombia and Venezuela); 'Unghuaray' (Peru)
(Pataua palm oil, similar in chemical composition and taste to olive oil)
This is a beautiful palm with feathery leaves up to 8m long. In the wild, these palms grow to 25m in height. It is social in habit and in certain ecological zones such as swamps, may occur in pure stands of tens of thousands of individuals.
Pataua' is a common species throughout the Amazon Valley and highly regarded by local inhabitants. The tree produces large clusters of dark purple, olive-sized fruits with a nutritious pulp and high quality oil. The oil, light green or yellow in color, is almost identical to olive oil in its physical and chemical properities.
In addition, the protein found in this fruit is comparable to that of good animal protein, and much better than most grain and legume sources of protein.
For example: in comparison with the value of soybean and animal protein, pataua' scored approximately 40% higher. Although the palms in this group are very slow growing, they provide a wealth of products to the local and indigenous communities, including thatch for roofing, fiber for arrow-heads and blow-gun darts, medicine from the roots and young seedlings, palm hearts, edible oil, protein rich meal, animal feed, fiber for backpacks and weaving as well as other products.
Orbignya phalerata Martius
Local names: 'Babassu' (Brazil); 'Cusi' (Bolivia)
The babassu palm is another plant native to the Amazon Valley, with a widespread concentration in areas close to this region, especially north-eastern Brazil.
Throught its distribution it forms the dominant vegetal cover over millions of hectares of forest. The babassu palm is valued by indigenous people for all of its parts, which provide important uses. In fact, the babassu palm is known as the "Tree of Life" as it is so important to the existance of people wherever it is found.
For example: the leaves provide thatch and can be woven into mats for constructing house walls, the stems are used for timbers and, most importantly, the fruits yield a variety of products.
Some of the products of the fruit, including fertilizer, alcohol tar and acetic acid, can only be derived through industrial processing while others, such as edible oil, charcoal and flour have been traditionally used by indigenous peoples throughout the region. The fruits of babassu look like small coconuts, born in clusters of a few dozen to several hundred. Some trees can yield up to one-half ton of fruits per year and these are gathered and cracked by hand on an up-turned ax head to separate the oil-rich kernal from the flour and shell which is later converted to charcoal.
The babassu palm has great potential for reforestation of degraded tropical ecosystems. Although it is somewhat slow growing, taking 15 to 20 years to mature, once established in an area, it is an extremely aggressive component of the ecosystem. As such, it could be introduced into many degraded sites, providing support for the soil, food and shade to the local animal population, and products to the humans that inhabit the region.
Hevea brasiliensis (Willd. Ex Adr. De Juss.) Muell. Arg.
Local names: 'Caucho' (Colombia); 'Seringueira' (Brazil)
Seringueira is one of the most important plants of the Amazon Valley and is known to the rest of the world as Rubber. About 99% of the world's natural rubber is produced from a fast-growing tree native to the lowland forests of the Amazon Basin.
The trees can grow up to 40m in height in the wild, but when introduced into plantations, the trees cease growth at 25m. The most important product of this plant is latex, obtained from the conduction cells and tapped by cutting into the trunk.
A knife with a V-shaped edge is used to cut channels into the tree at angles of 25 to 30 degrees, beginning from the top left and extending to the bottom right. Botanists currently recognize nine species of Hevea. Hevea brasiliensis is the most important, but others have resistance to diseases such as the South American Leaf Blight. This plague has resulted in major devastation to rubber trees planted in the Amazon region.
Thus, by growing different species, disease problems could be overcome. The industry based on harvest of wild trees collapsed with the introduction of cultivated rubber to the Old World tropics in the early 1900s, and todaythere is limited production of wild rubber in the Amazon. Local harvest cannot compete with the mechanized modern plantations established in countries such as Malaysia, and for the moment, the production of rubber in the Amazon Valley is of minor importance.
In conclusion, the plants of the Amazon have always provided its inhabitants with products to their subsistence and economic livelihood. These include rubber, gums, waxes, fibers, oils and foods. The study of the relationship between plants and people is known as ethnobotany, and certainly the Amazon Valley is an extraordinary place for the study of this science.
Tragically, deforestation is reducing the genetic diversity of the tropical regions around the world and, as forests are destroyed, valuable plant and animal species are driven to extinction. Conservation must involve not only preservation of valuable species in botanical gardens, seed banks, and other such collections, as well as preservation of wilderness regions of such great value to civilization.
Michael J. Balic, Ph.D.
Philecology Curator and Director
Institute of Economic Botany
The New York Botanical Garden
Bronz, New York 10458-5126