Amazon forest has been inhabited since the beginning of humanity. It is esteemed that some million of indigenous people already lived here when European colonists arrived in the region in XVI century. The modern occupation of the Amazon forest started around 1540, however, until the end of the Second World War, the human being presence almost did not change the environment and natural vegetal covering. A new period started with the politics, mainly in Brazil, aiming at the agricultural development and the nesting of immigrants, deriving of densely populated and/or devoid regions. All these modifications in the Amazon region can have climatic, ecological and ambient implications for the region, the continent and the globe.

The INPA (National Institute of Research of the Amazon region) has given an important contribution to the scientific and technological knowledge of the Amazon region. The set of this knowledge constitutes the greatest and more important bank of scientific information on the Amazon region, whose consultation became indispensable for a correct creation of regional public politics.

The Amazon region occupies area of 6 countries: Bolivia, Brazil, Colombia, Equator, Peru and Venezuela. It represents in numbers:

> 1/20 part of the terrestrial surface.

> 4/10 of the South America.

> 3/5 of Brazil.

> 1/5 of the available worldwide freshwater.

> 1/3 of the worldwide reserves of tropical forests.

69% of this area belongs to Brazil, enclosing the States of Pará, Amazonas, Maranhão, Goiás, Mato Grosso, Acre, Amapá, Rondônia and Roraima. The 4.871.000 km2 of lands, waters and forests, shelter 10 million inhabitants, only two and half thousandth of the world-wide population, with a 2 density of hab./Km2.

The Amazon

> Total area (Great Amazon): 7.584.421 Km2 (including 9 countries).

> Brazilian area: 5.033.072 Km2.

> Amazon Basin (excluding Tocantins, Maranhão and Mato Grosso States): 4.982.000 Km2.

> This value represents 7% of planet surface.

> The Amazon region shelters about 50% of worldwide biodiversity.

The Forest

> 78% of Terra-Firme (Forest that never flooded) soils are acid and low natural fertility.

> It is esteemed a total of 19 millions Km2 of tropical forests.

> The Amazon possesses 3.650.000 Km2 of continuous forests, the biggest of world.

> Average temperature: 26ºC;

> The period (the time of the day) varies of 30 to 50 minutes, between the longest and shortest day.

> The annual amount of rain in the Amazonian basin: 15 trillions m3.

> Of this amount, in average 48% is used and evapotranspirated by the Amazonian ecosystem; others 52% flows off for rivers, approximately the half. The rainforest ecosystem changes significantly this average: in its environment, only 25% is evaporated and 25% goes to the rivers: the major part is retained in the forest itself.

> The liquid production of oxygen (surplus) is in average of 96 tons per year, that represents 0.000008% of the total of the atmosphere of the land. This indicates to be a small global participation.

> However, recent studies show that the amount of carbon settled for the forest is significant, and therefore the Amazon region can be interpreted as being an ecological filter, therefore it reduces the amount of CO2 of the atmosphere.

> A total area deforested is calculated in the Amazon region of about 500 a thousand km2, or either, about 12,5% the original forest. In the decade of 80, in Rondônia, the deforestation tax was of the order of 35 a thousand km2 per year, equivalent to a field of soccer (1 ha) to each 5 seconds.

> There are in the Amazon region about 5.000 species of trees (bigger that 15cm of diameter). In the Inpa collection there are 10,200 exsiccates, being of about 3.500 species. In the North America there are about 650 species of trees.

> The diversity of trees in the Amazon region varies between 40 to 300 different species per hectare, comparing 4 to 25 in the North America.

> Of 250,000 species of superior plants of the World, 170,000 (68%) live exclusively in tropics, being 90,000 in the South America.

The Population

> About 17 million people live in the Amazon region, and therefore the demographic density is of about 3,4 inhabitants for km2.

> 62% of the population live in urban zone and 38% in the rural zone.

> In average, during the year, the "caboclo"(inland people) uses about 3.2 hours/day for agriculture and 5.1 hours/day the extraction activities (hunting, fish, collect...).

> The oldest ceramics found in the Amazon region date of about 7.000 the 8,000 years.

> Of the parasitic illnesses of the population, the malaria is the main endemic disease. It was verified in Porto Velho 90% of the total population has caught malaria at least once; Boa Vista 82%; Macapá and Rio Branco 22%, Manaus 14%; Palms 11%, Cuiabá 6% and Belém 0,2%.

> The region (inland) has one of the biggest animal protein consumption (fish) in the world: 140 gr per person/day.

> In the total area, 70% of children has nanism and 18% nutritional atrophy; 37,5% of anemia; 56,5% lack of zinc and 50% lack of calorie, iron, vitamin and other vitamins.

> In the urban area 72.2% of malnutrition were detected.

The Rivers

> Volume of water in the estuary of the Amazonas River: 100 to 300 m3/s, depending on the time of the year.

> Considering the average of 200 m3/s, this means the daily consumption of a city of 2.000 inhabitants would be supplied by one second of the volume of the river.

> The amount of water of the Amazonas River represents about 17% of all the liquid water of the planet.

> The average depth is of 40 the 50 meters, being able to reach up to 100 meters, next the Óbidos City.

> The effect of the tides can be perceived until 1,000 km of the sea (Óbidos).

> Basically, there are three types of rivers:.

> White or clay water (Solimões, Amazonas, Madeira...) with visibility the 0.1-0.5 meters; pH 6.5-7.0.

> Black water (Negro, Urubu...) visibility of 1.50-2.50 meters, pH 3.5-4.0.

> Clear water (Tapajós, Trombetas...) visibility more than 4 meters, pH 4.0-7,0.

The Fauna

> There are about 3.000 species of fish in the Amazon region, that represents 85% of South America and 15% of continental waters. The INPA has registered 40% of this total.

> In State of Amazonas, only 36 species are explored. 90% of fish are represented by 18 species, but 61% are of 4 species: Tambaqui (18%), Jaraqui (32%), Curimatã (11%) and Pacus (5%).

> The last estimates are that the pluvial forests of the world can have up to 30 million species of insects.

> In an only plant in the Amazon region had been found more than 80 species of ants, representing the double of the species of ants found in the British Islands.

> The great insects of the Amazon region:
bigger beetle: 20 cm
bigger fly: 5 cm
bigger chinch-bug: 10 cm
bigger dragonfly: 15 cm
bigger butterfly: 30 cm
bigger buzzer: 9 cm
bigger wasp: 7 cm.

More about fauna in the region of Cuieiras River: Cuieiras river/Monkeys & Cuieiras river/Birds

Source: Instituto Nacional de Pesquisa da Amazônia - INPA -
Responsible: Dr. Carlos R. Bueno - Coordination of Extension Dept. in 2002.