Tropical Rainforests and Their Deforestation

Date: 2015-10-07; view: 420.

A). Read the text and correct the statement below.

Every hour over ten thousand people are born in different parts of the world that's three humans every second. The human population has now reached over 6 billion and is predicted to reach 9 billion by 2050, stabilizing at some point in the future between 9 to 12 million. This phenomenal increase in humans has brought about large scale changes to the biosphere and atmosphere as humans rush to claim the earths finite resources to match the consumer lifestyle that people in the developed world, and increasingly more the developing world, lead. One such over-consumed ecosystem is the tropical rainforest which is being deforested at an alarming rate to fuel human consumerism.

Tropical rainforests form a lush but now fragmented green belt around the earth's equator. They are the most bio-diverse ecosystems on earth. Tropical rainforests cover just six percent of the worlds land mass yet they harbor half of the world's land species.

Tropical rainforests in Columbia, Ecuador and Peru comprise two percent of the earth's surface and yet contain the highest biodiversity of plants on earth having some

40, 000 species of plants. Indeed seventy percent of all the world's plants are found in tropical rainforest. Moreover, it is believed that fifty percent of all species currently on earth live in rainforests estimated to be between one to fifteen million species.

Tropical rainforests hold a plethora of insects, birds, mammals, amphibians, reptiles far exceeding any ones most vivid imagination before their discovery. There are the great apes such as the formidable mountain gorillas in central Africa, the chimpanzees, our closest living animal relatives and orangutans. Other mammals include different species of tigers, jaguars, monkeys, slow loris and even slower sloths, deers such as the diminutive, shy, knee high lesser mouse deer, forest elephants, the bizarre and elusive okapi, half striped half chocolate brown and a relative of the giraffe nobly strolling through the rainforests of central Africa daintily feeding on fruits and leaves. There are reptiles such as chameleons with their ability to change into a multitude of colours, amphibians such as frogs resembling bird droppings and the splendid tree frog with its green upper body, yellow under body and bright red eyes ringed in black.

There are hundreds of thousands of insects including insects resembling leaves and sticks, a diverse array of beetles and thousands of coloured butterflies darting in and out of the leaves in a rainbow of colours. Bird life is also prolific and there are a multitude of coloured birds including parrots and toucans, and parakeets darting in and out of the trees.

As well as the rich biodiversity and aesthetic appeal, tropical rainforests provide a home to many indigenous people with rich and unique cultures. The "back to nature" artistic movement that flourished in England early in the 20^th century focused on tropical rain forests and inspired some of the most luminous literary description of the period. W. H. Hudson's romantic fantasy "Green Mansions" and Arthur Conan Doyle's "Lost World" were set partly under the cathedral-like arches of Amazon rain forests, and Joseph Conrad's evocative "Heart of Darkness" was based on the author's experiences with rain forests in the Congo.

Well into last century a hint of somewhat sinister mystery pervaded the great rain forests; within living memory, headhunters roamed the Peruvian forests from which the Amazon springs, and even today vestiges of forest Indian culture survive in Brazil and elsewhere in South America.

Tropical rainforests also provide foods, medicines, and other resources. Think of the jungle fowl, from which we derived chickens, nuts such as brazil nuts, bananas, chocolate and spices, anti-cancer drugs from the Madagascan periwinkle, quinine from cinchona bark, rubber for tyres and other uses tapped from rubber trees and many other yet undiscovered foods, medicines and products. All these products can be harvested sustainably to provide peoples needs and benefit local people and the economy.

Tropical rainforests are essential for local climate and the global climate being important for water and carbon cycles. Vast amounts of water are taken up by rainforest trees and vegetation and released again during transpiration. This natural cycling of water maintains the local climate and prevents flooding.

Tropical rainforests are being deforested at an alarming rate.

Each year hundreds of thousands of hectares of tropical rainforests are being opened for logging and then for clearance for plantations for planting sugar cane, for bio-fuels, for growing oil palm plantations and for raising cattle. All of these practices provide short term gains and in their wake some 2 or 3 years later leave a dust bowl where a rainforest once stood. Tropical rainforests are complex ecosystems and nutrients from fallen leaves and debris are quickly recycled in the hot, humid environment and reabsorbed by the trees and vegetation. This rapid recycling of nutrients into the trees means that the soil is nutrient poor, and after the trees are removed the soil quickly becomes depleted of nutrients and is unable to support plantations or cattle and the land is soon barren and abandoned. The barren land is exposed to the elements and wind and rain soon wash away the top soil until a dust bowl remains. The top soil is washed away to lower ground and silts up rivers leading to localized flooding of villages and towns.

Without tropical rainforest trees and vegetation to take up water the water cycle changes and there is further and more extensive flooding. Rainforest vegetation is a voracious consumer of atmospheric carbon dioxide, which is increasing at a troubling rate leading to enhanced global warming and climate change on a global scale. It is estimated that deforestation accounts for 25% of the annual emissions of carbon dioxide and other heat trapping gases. Saving tropical rainforests is at the heart of preventing climate change. The deforestation of tropical rainforests is leading to a phenomenal loss of global biodiversity and the consequent loss of medicines, foods and other resources. Deforestation is also leading to localized changing weather patterns, flooding and an increase in carbon emissions and climate change. The loss of the rainforests is affecting the entire planet and needs to be halted right now.

1. The main reason of rainforest deforestation is growing cities.

2. Rainforests are valuable due to geographical position.

3. Rainforest species biota covers two percent of the earth surface.

4. Rainforests make the ground for Western underground cultures.

5. Food and medical products provide by the rainforest may be harvested on condition of the inevitable extermination of some species.

6. The word ‘sustainable' in the text means ‘supportive'.

7. Natural cycling of water in the rainforest is concluded in increasing precipitation.

8. The long-term result of rainforests deforestation is the soil able to support plantations.

9. Among the most destructive consequences of rainforest deforestation they name rising global sea level;

(b) Look at the NASA photos and graphs depicting the rate of the rainforest deforestation.

Taken by NASA's Landsat 1 satellite in 1975 and 2012, the two images reveal dramatic effects of clear-cutting for roads and agriculture in Rondônia, a rural state in western Brazil. This process began with the construction of a major north-south highway in the 1970s, according to NASA's Earth Observatory, followed by secondary roads through dense forest at right angles to the first road. As settlers continued expanding over the decades — first by cutting down trees, then burning ground cover — their merging agricultural tracts took on a "fishbone pattern," as NASA describes it.

The rate of Amazon deforestation is now much slower than it used to be, having fallen nearly 80 percent since its most recent peak in 2004). Yet roughly 224,000 square miles of the rain forest have still been lost since 1980, including more than 1,000 square miles per year in Rondônia from 1980 to 1992. And deforestation speed isn't necessarily the most important stat to measure.

"Because these roads cut deep into the rain forest and then spread outwards, there's a much greater loss of habitat and species than if there was a single area of deforestation," Tucker says in a NASA statement accompanying the photos, "because the amount of edge is critical for biodiversity."

Even at relatively slow rates of destruction, the effect on biodiversity can be devastating if wildlife habitats are fragmented — a distinctive effect of Rondonia's fishbone pattern, Tucker and Skole found, because it creates more exposed edges between clear-cut areas and intact forest. These "edge areas" not only suffer more from wind damage and desiccation, but they also provide humans with easier access for hunting, poaching, animal capture and logging.

(c) Using the information in 3 (a) and (b), fill in the chart below and organize a short panel discussion distributing the aspects among reporters: Rainforests: Will they Stay?

For reference as for reasons and threats of deforestation you may use the following sites Mongobay.com; Rainforest Information Centre.

(d) Look at the map of deforestation hotspots and comment on it using facts about forests below.

10 Facts about Forests

01. The total forest area of the world is just below 4 billion hectares, nearly 30 percent of Earth's area. Russia contains the largest forested area, followed by Brazil, Canada, and the United States. Tropical rainforests cover an area larger than Europe.

02. Over 1 billion people rely on forests for their livelihoods. Around 60 million indigenous people, about the population of the United Kingdom, depend on forests. A third of the world's people use biomass fuels, mainly firewood, for cooking and heating.

03. The world's rainforests are home to half of life on earth. The Amazon is the richest biodiversity hotspot in the world, holding about a quarter of land species.

04. Tropical and temperate forests absorb around a ton of CO2 per hectare per year from the atmosphere. Due to the depth of peat, one hectare of tropical peat forest can store 3000 to 6000 tons of carbon per hectare.

05. An area of rainforest the size of a football pitch is lost every four seconds. About 13 million hectares of tropical forests are destroyed each year, an area nearly twice the size of Belgium.

06. The highest levels of deforestation are in South America, with 4.3 million hectares lost per year. The fastest rates of deforestation are in Southeast Asia.

07. Deforestation and forest degradation releases about 1.7 billion tons of carbon annually, about 20 percent of global carbon emissions. Total emissions from deforestation in 2008-2012 are expected to equal 40 billion tonnes of CO2.

08.The biggest causes of deforestation and forest degradation are agricultural expansion,cattle ranching, road and urban infrastructure development, commercial logging, mining, subsistence farming, and collection of firewood.

09. The United States is the world's biggest supplier of wood, with nearly 20 percent of the world market. It is followed by Brazil, Canada, Russia and China. According to WWF, nearly 30 percent of the EU's timber imports could be from illegal logging.

10.To halve emissions from the forest sector by 2030 through carbon markets would cost between 17 and 33 billion dollars a year, according to the Eliasch Review. The EU reckons that it would cost 15 to 25 billion euros every year to halve deforestation by 2020.