Presentation on theme: "Amazon Rainforest: Physical Features World’s largest rainforest 5.5 million km² or 1.4 billion acres (2/3 the size of the continental U.S.) Accounts for."— Presentation transcript:
Amazon Rainforest: Physical Features World’s largest rainforest 5.5 million km² or 1.4 billion acres (2/3 the size of the continental U.S.) Accounts for 54% of Earth’s rainforest Spans 9 countries Brazil (60%) Peru (13%) Columbia Venezuela Ecuador Bolivia Guyana Suriname French Guiana Average annual precipitation: 9 feet Wettest areas can receive up to 35 feet Average temperature: 72-93°F Produces more than 20% of Earth's oxygen, thus the name "Lungs of the Planet"
Amazon Rainforest: Flora & Fauna More than half of the world's estimated ten million species of plants, animals and insects live in tropical rainforests. At least 40,000 plant species More than 3,000 fruits are found in the rainforest 200 are now in use in the Western World The natives of the rainforest use over 2,000 70% of plants found to have anti-cancer properties are found only in the rainforest. An estimated 90% of Amazon rainforest plants used by Amazon natives have not been studied by modern science. Roughly 30% of the worlds animals 90% are insects 1,500 species of birds (1/3 of the world’s total) Over 400 species of mammals Extremely dense growth One hectare (2.47 acres) of rainforest can contain over 750 types of trees and 1500 species of plants.
Amazon rainforest is vertically divided in four layers and each of them has a unique ecosystem, animals and plants... Overstory (Emergent) Uppermost layer – roughly 125 feet and above. The tallest trees are found here, towering as much as 200 feet above the forest floor, with widths reaching up to16 feet around. Many of the rainforest birds, including eagles and parrots inhabit this layer. Canopy Roughly 75 to 125 feet. The primary layer in terms of plants and animals - an estimated 70 to 90% of life in the rainforest exists in this layer. Leaves in the canopy act like miniature solar panes. Through photosynthesis - the process of converting sunlight into energy - they provide the source of power to the forest. Thus, plants in this layer have a higher yield of fruits, seeds and flowers, attracting a wide range of biodiversity. In addition, they play an important role in regulating regional and global climate, because it's the principal site of interchange of heat, water, vapor and atmospheric gases. Understory Between the forest floor and 75 feet. Little sunshine reaches this area - only 2-15% of the sunshine that falls on the canopy. Plants have to grow larger leaves to reach sunlight, thus there are large numbers of ferns and orchids. Forest Floor: Darkest area of the rainforest - less than 2% of sunshine reaches the forest floor. As a result, decay of of organic materials occurs quickly in this layer. Home of the largest animals of the forest. Amazon Rainforest: Layers
Amazon Rainforest: Peoples Pre-colonial populations: estimates vary widely Between 2-9 million, of which at least 1 million were in Brazil Current native population estimated at 250, , ethnic groups 170 different languages There is some evidence that Amazon tribes may be living in the depths of the Amazon rainforest that have never had contact with the outside world. The majority of the current population of the Amazon is located along the Amazon River in larger cities. CityCountryPopulation BelemBrazil1,912,600 ManausBrazil1,524,600 IquitosPeru349,300 MacapaBrazil301,600 Porto VelhoBrazil292,000 SantaremBrazil192,300 Largest Amazon Cities
Amazon River Facts World’s 2 nd longest river (Nile is 1 st ). 3,900 mi (6,280 km) long. Average depth of 150 feet. Width ranges from 1 to 35 miles. Drainage basin (the Amazon Basin) of roughly 2.5 million mi² (40% of South America). Carries more water than any other river in the world. Formed by the junction of two Peruvian rivers, the Ucayali and the Marañón, which flow out of the Andes Mountains
Deforestation: Facts and Figures Since 1970 roughly 825,000 km² of rainforest have been cleared (15% of total). Deforestation has slowed in recent years due to the global economic recession. The historical rate of deforestation has been closely tied to the state of the Brazilian economy. Recent data indicate deforestation is again rising (nearly 12,000 km² in the last calendar year). Rainforests once the covered 14% of earth's surface, but now cover only 6%. Pessimistic estimates indicate rainforests could disappear within 40 years.
1970: The National Integration Program (PIN) provided impetus for the road building boom. Transamazon highway connecting Amazon with NE Brazil. Cuiaba-Santarem highway linking Amazon with S & SE Brazil. Rationale for PIN: Transamazon highway would provide solution to drought problems in NE Brazil by creating jobs for displaced NE families. Alleviate population and social pressures in NE Brazil and promote occupation of Amazon Uncover mineral deposits during road construction. Other motives: national security and fear of foreign domination in the region : INCRA (National Institute for Colonization & Agrarian Reform) established network of villages, towns, cities along the highway and demarcated 100 hectare farm plots with goal to settle 70,000 families. Road building supported by loans from World Bank and Inter American Development Bank in 1980s. A Little History In the 1970s and 1980s the Brazilian tended to see the Amazon as an underused resource.
Deforestation: Why? Logging Cattle Ranching Commercial Farming Subsistence Agriculture and Settlement Mining Hydroelectric Dams Road Building
Logging Commercial logging / timber extraction is one of the largest causes of deforestation. Logging companies sell timber, mainly for use in the construction and furniture industries. Additionally, the paper industry requires a massive amount of pulpwood trees. In order to satisfy the world's demand, more and more of the rainforest is burned and replanted with pulpwood trees.
Foreign companies (fast-food companies, beef industry) have bought large areas of the Amazon which they have turned into cattle ranches. Grazing land degrades fast due to the lack of gradients and overgrazing, which means new rainforest land needs to be obtained to satisfy their needs. Brazil is now home to the world's largest marketable herds of cattle(166 million head), and ranks fourth worldwide in beef exports. Cattle Ranching
Large-scale Plantation Farming Cash crop production (e.g. rubber, sugar, coffee) by large companies can account for large areas of the forest being cleared. Soybean is the largest crop. It is estimated that less than 10% rainforest land is suitable for conventional agriculture. Furthermore, the soil quickly deteriorates due to lack of sustainable cultivation practices. As a consequence, more land must be cleared so that agricultural production can continue. Commercial Farming
The government relocated large numbers of people to small farms in the Amazon rainforest in an attempt to provide opportunities for land-less farmers, alleviate poverty, increase political control over the region, and to reduce the pressure on over-crowded urban areas in the south-east of Brazil. The vast majority of these people are engaged in subsistence agriculture. Erosion and poor soil quality, which lead to declining crop yields, often lead families to move in search of new land to clear within a few years of settlement. Several larger cities have developed along the Amazon River over the past 30 years. Subsistence Agriculture and Settlement
Slash and burn techniques are used to clear the land for settlement, agriculture, and ranching.
Mining Large quantities of valuable natural resources have been discovered in the Amazon Rainforest. They include iron ore, bauxite, gold and other minerals.
There are two types of miners in the Amazon: 1)Those that work in the official mines, which are regulated by the Brazilian government. 2)Illegal miners such as the gold prospectors (garimpeiros). Both groups have caused damage to the ecosystem by cutting down large areas of forest, and by using chemicals to purify their metals. However, the official mines have made some efforts to repair some of the environmental damage they have caused. For example, at a large bauxite mine on the Trombetas River in the state of Para, the mining company has stopped dumping their tailings (sludge from washing the ore) into the river and they have started a reforestation project. The garimpeiros are more difficult to monitor. They use enormous amounts of mercury to purify the gold and this toxic metal is released into the rivers and is absorbed into the food chain. Mining
Hydroelectric Dams Dams have an impact on the local wildlife, especially affecting migratory fish. Reservoirs have displaced many native peoples that lived upstream from dam sites. Furthermore, reservoirs have also served as breeding grounds for diseases, and insects that carry diseases (i.e. mosquitos).
Road Building Roads have been built through the Amazon to facilitate development in the region, transport timber, cattle, minerals, and crops, and to move heavy equipment. Since the 1970s, more than 9,000 miles of road have been built through the rainforest.
Roads Population Agricultural Profitability Colonist Turnover Deforestation Clearing Per Colonist (+) Positive feedback loop Causal loop diagram adapted from “Deforestation and International Economic Development Projects in Brazilian Amazonia” by Philip M. Fearnside Linking Population Migration and Deforestation “Roads facilitate entry of settlers whose land claims (established by deforestation) justify building more roads.” (Feanside-Deforestation…, 214)
In 2000, the Brazilian government introduced a development plan which aims to create roads, railways, waterways and hydroelectric dams in the Brazilian Amazon region. 338 projects throughout Brazil US $43 billion in development projects over 8 years. Called for paving an additional 7,500 km of highways in Amazonia. ç Many analysts believe that Avança Brasil owes its origins to the IMF restructuring of Brazil in the late 1990s (like many Latin American countries, Brazil was a victim of the debt crisis). Structural adjustment requirements included increasing Brazil's export earnings, attracting more foreign investment, and expanding the construction industry. Rainforest Development: Avança Brasil (Advance Brazil)
Why Build Roads: The Economic Perspective World demand for cheap supplies of mahogany and other tropical timbers. When contractors build roads into forest-rich regions, they improve access to urban markets which sparks additional logging (and other economic activities) along the roads. When contractors pave dirt roads, access improves again, which continues to increase land-clearing and production. The Brazilian government argues that the rising population needs land to improve their quality of life, and the country needs to make money from natural resources to industrialize and to pay off foreign debt.
Avança Brasil (Advance Brazil) Social, Economic and Political Expectations of New Roads -Increased available land -New access into pristine, previously undisturbed forests -Onset of new agriculture -Lower transportation time (as opposed to barges and ships) Increased capital/ Economic development
What will this do to the Amazon? Scenarios suggest that, fully implemented, Avança Brasil will lead to the loss of between 28% and 42% of the Brazilian rainforest by This is an annual increase in forest loss of between 14% and 25% over pre-project estimates. Tropical land temperature could potentially increase between 2˚C and 8˚C. Average global temperatures are likely to rise by 0.1˚C to 0.3˚C. Road networks will effectively fragment the most dense and remote areas of the Amazon Rainforest and leave it vulnerable to destruction through fire. A likely increase in illegal mining and logging activities. Will allow for easier transportation routes between cities and ports. New roads increase access for new migrants and increase the amount of land available for colonization. Highway construction in the Amazon over the last 20 years has resulted in considerable land conversion from tropical forests to farming.
What will this do to the Amazon? Impacts on Wildlife: Roads have not only caused deforestation, but also fragmentation, both of which are harmful to animals and plants Roads have 3 major negative effects: 1) Creation of edge effects – some species won’t cross roads. 2) Promotion of invasive species. 3) Increase of human disturbances and hunting. Roads have the potential to not only divide populations into smaller ones, but in doing so they increase species’ vulnerability to decreased genetic variation and thus make local populations extinct