Current Issues
There are many issues and problems associated with the Amazon. I will discuss threats to the Amazon floodplain as a whole, and then discuss threats to each individual várzea.
Roads, Settlement, and Development
Historically, the Amazon basin had always been isolated from the rest of Brazil. This was because the only transportation routes were via water, and that great distances were involved. There were few if any routes of transportation over land. Even by 1960, the entire Amazon contained only 6,000 km of roads.
Because the only transportation involved water, population centers in the Amazon were clumped along the major waterways. Only a few native tribes lived in the surrounding rainforest. This population clumping meant that
disturbances to the forest were generally confined.In the last four decades, the lack of roads began to decrease. In 1964, a highway was finished, which was 1,900 km long. Gradually, the number of roads increased. The Brazilian military, which had gained control over the Brazil government in 1964, was committed to occupying the northern region of Brazil, in order to exploit its resources and to build roads. By 1980, the road system had grown to 45,000 km.
The main reason Brazil was moving in this direction was political in nature. Many neighboring countries had already created programs to colonize
and develop their Amazonian land. This made Amazonian Highway Road in Brazil
Brazil's leaders anxious to have national sovereignty,
which would be ensured by creating self-sustainable frontier settlements. Roads were essential for this purpose, as several large cities on or near the Amazon were now connected to southern Brazil.
Roads and settlement both have an impact on deforestation and habitat destruction. Most importantly, roads allow more and more people to settle in the area (which is why Brazil wanted them in the first place).
Logging
Not surprisingly, indigenous people in the Amazon had only a minor impact on the trees in the Amazon
floodplain. When commercial logging began, it started in river channels, rather than in the floodplains.
This is because trees on the river grew right to the rivers edge,
and the soils were undercut during floods. The trees would come
loose, flow down the river, and easily be taken (due to deforestation,
the amount of deadwood that flows down the river like this now is much
smaller. Large-scale commercial logging began in the floodplains
in the 1860's, when steamships were brought into the Amazon. As
cities grew explosively in the 1960's, so did the logging operation, in
order to meet construction demands. By 1980, most of the precious
species in the Amazon floodplain had been logged out.Logging in the Amazon Sadly, because of the depletion of this resource, floodplain logging was even
(click to enlarge) affecting protected areas. The Mamirauá Ecological Reserve is one of few
places left in the Amazon with a large natural floodplain ecoystem. It is very unfortunate that logging is being allowed here, as Mamirauá is the only reserve along the Amazon. The reserve belongs to the government, but is managed by local peoples. This community-based management is being used as an experiment for an administrative tool. As a result, there is little outside police involvement. Unfortunately, logging concentrates on species after species, as overexploitation takes effect.
Today, little commercial logging takes place in the Amazon, mainly because there is little to log. In addition, no reforestation or planting of desirable species has been attempted. Also, no studies have been conducted about floodplain.
Hydropower
The Amazon has one of the largest untapped potentials for hydroelectric power in the world. Several
hydroelectric dams have been proposed in the past, as a result of
Brazil wanting to be less fossil fuel dependent. Luckily, the
largest of these proposals have failed. If dams were built on the
scale that has been proposed, there would probably be a greater
destruction of biodiversity than anywhere else on earth. On the
other hand, because of rich mineral resources, explosive population
growth, and high levels of poverty, the Amazon region won't be able to
develop without additional sources of energy. Perhaps this is for
the best in some ways, because development would be as harmful to the
biodiversity in the Amazon as developing hydropower would be.One dam, Tucuruí, located on the Rio Tocantis, began operating in 1984. This dam is 1,200 meters wide (3937 feet, 3/4 of a mile). Tucuruí Dam
The dam's current capacity is 8,400 megawatts. There are many
problems associated with the dam, both environmental and social. Flooding caused by the dam creates loss of timber, loss of natural ecosystems, and an increase to greenhouse gas emissions. Aquatic systems are affected by the block the dam creates to fish migration, as well as the creation of an anoxic environment. The anoxic water is worsened by vegetation decay, and the anoxic water corrodes turbines. Matters are worsened by the fact that environmental studies have almost no influence on decision making. Social problems include the impact the dam has on indigenous people, resettling a displaced population (when the dam was built), loss of fish and other resources that people downstream from the dam relied on, and health problems, including malaria, a mosquito plague, and mercury accumulation in fish (and in people who consume the fish). Also, an aluminum industry uses 2/3 of the power Tucuruí generates. This completely alters the Brazilian energy economy, as other dams must be built to supply power to cities. Without the aluminum industry, power from Tucuruí could go to cities, reducing environmental impacts involved in creating other dams. These social and environmental problems are given no consideration when decisions are being made.
Gold, And Other Mineral Extraction
Natural gas has been discovered in the western
Amazon, and oil in Ecuador and Peru. Despite this, it seems that
the Amazon basin is richest in minerals. These include bauxite,
iron ore, manganese, and most importantly, gold. In recent
decades, gold has been the most valuable resource exported from the
Amazon, with annual revenues between one and three billion dollars.
Despite this, little scientific research has been done to
determine the environmental effects of mining.Gold Mining in the Amazon.
Current Status of Várzea
Gurupa
Main activities on this várzea include subsistence agriculture, fishing, selective logging, and ranching. The forest on the banks of the Lower Amazon, as well as the natural savannas, have been cleared and altered to create pasture for grazing animals. Some urban areas are located on the river bank, reducing natural habitat. Also, several major timber species are nearly depleted.
Habitat at Gurupa is threatened by human alteration. The savannas are taxed by cattle and water buffalo. The fertile soils have attracted large-scale agriculture, which obviously degrades habitat. Logging and fisheries operations are a threat to species populations.
Iquitos
The Iquitos várzea is highly affected by human activities because it lies along water "highways." Most of the várzea is used by small farmers for agriculture and managed forest. These systems usually are very biodiverse. Despite this, Iquitos suffers from heavy deforestation. Part of Iquitos is protected by the Pacaya-Simiria National Reserve (20,000 sq km).
As with Gurupa, the main threat to the várzea is human alteration of habitat. At Iquitos, gold mining is contaminating rivers and fish. Heavy sedimentation from forest degradation is threatening animal habitat. Mahogany and other timber species have been wiped out in certain areas, as well as the tapir and many species of primates. Fish and aquatic mammals are being threatened by river contamination and commercial fishing. Patches of floodplain forests are burned and cleared, to encourage native grasses to grow for livestock grazing. This destroys habitat and food for many fish species.
Marajó
As with Gurupa and Iquitos, Marajó is greatly affected by human activities (especially because it is located at the mouth of the Amazon). The natural habitat and biodiversity have been highly degraded by large-scale agriculture, forestry, and ranching. None of Marajó is protected. The largest source of depredation is by cattle and water buffalo ranching. Their replacement of native grazing animals, such as deer and tapir, highly degrades the natural grasslands. Ranching also reduces habitat for capybaras and manatees, since they must compete with cattle for vegetation. Fruit-eating fish are becoming rare or extinct at Marajó, due to habitat depredation and loss of food availability.
Monte Alegre
The main human activities at Monte Alegre are subsistence agriculture, fishing, and selective logging. A lot of the forest is intact (although it is secondary forest), although there is degraded forested habitat, mostly where cattle are grazed. Like Iquitos, this várzea has rivers and fish that are contaminated by gold mining activities. Monte Alegre is suffering from heavy sediment buildup, a result of forest destruction. Not much of this várzea is protected. The Lago Aiapuá State Reserve is located at the edge of the várzea, near the Purus River, and covers 6,100 sq km.
Purus
Most of this várzea is used for agriculture and forestry by small farmers. Some small-scale ranching and logging also takes place. Fish populations are very threatened by large-scale fishing. High collection of some aquarium fish are also threatening. Gold mining contaminates fish. In some areas, large-scale cattle ranching and commercial logging is threatening the forest. Purus might be better off in terms of conservation than other várzea, as it is part of a large corridor of protected areas which have strong conservation programs.
< Click for Conclusion >