Biodiversity and Change


Biodiversity Definition: Biodiversity simply means the variety of flora and fauna (plants and animals). Tropical rainforests are considered to be biodiversity hotspots because they have a large amount and variety of plants and animals - most of them unique to rainforests. They contain over 50% of the world species in only 7% of the land area. They are home to 90% of insect species and 80% of primate species.

Flora: This simply means plants or vegetation.

Fauna: This simply means animals.

Deforestation: When areas of forest cover are removed.

Reforestation: When areas that have previously been deforested are replanted.

Afforestation: When areas of land that previously had no forest cover, are then planted with trees.

UNEP: The United Nations Environment Programme coordinates environmental activities and helps countries implement environmentally sound development policies.

CITES: The Convention on International Trade in Endangered Species of Wild Flora and Fauna is a multilateral treaty designed to ensure that the trade in animals and plants does not endanger their survival.

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Tropical Rainforests


Tropical rainforests are mainly located between the tropics. The Amazon rainforest in South America is the largest rainforest in the world, but there are also large areas of rainforest in the Congo Basin, SE Asia, Central America, Southern India and Northern Australia. Tropical rainforests cover about 7% of the earth's surface. There typical climate are daily temperatures between 20c and 45c and annual rainfall of 125cm to 650cm. Rainforests tend to be very humid and experience thunderstorms in late afternoon. Rates of deforestation vary widely and even with the use of satellite images are hard to accurate clearly. Estimates claim about 1 and half acres are cleared every second which accounts for the area twice the size of Florida every year. Scientists believe that in 40 years all major rainforests may have disappeared.
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Why are Rainforests Important?

Why are Rainforest Being Destroyed?

What Problems Does Rainforest Destruction Cause?

  • Biodiversity: Although rainforests cover only 7% of the world's land mass, it is estimated that they could contain up to 50% of the world's biodiversity. This is potentially up to 15 million species.
  • Photosynthesis: Tropical rainforests are often referred to as the 'lungs of the earth' and convert large amounts of the greenhouse gas carbon dioxide back into oxygen. It is estimated that the Amazon rainforest alone produces about 20% of the earth's oxygen.
  • Flood control (interception, transpiration): Rainforests are an excellent natural measure to reducing flooding. There is leaf cover in rainforests all year so interception continually happens, extending rivers lag time. All vegetation uptakes water and transpires it.
  • Control of soil erosion: The root systems of trees and shrubs hold the very thin soil of rainforest in place. If trees are removed then both erosion of topsoil and landslides are more likely
  • Source of nutrients to humus layer in soil: The topsoil in rainforests is very thin and relies on the nutrients provided by rotting plants and animals. Because of the rainforests climate, there is a constant supply of leaf litter.
  • Medical remedies: Rainforests have been the source of many of today's drugs, including the basic ingredients for the hormone contraceptive pill, quinine (an anti-malaria drug) and curare (a paralysing drug).
  • Cash crops and agricultural products: Yam, coffee, rubber, mango, banana, sugarcane, cocoa and avocado were all first discovered in rainforests.
  • Ecotourism: With people becoming ever more environmentally conscious and looking for increasing adventures, ecotourism to rainforests is increasing. This not only helps protect rainforests, but creates income for locals. Ecotourism is an important income to countries like Costa Rica and Belize.
  • Home to indigenous groups: Although the number of indigenous groups and people have declined rapidly since colonisation in South America, it is estimated that there are still over 200,000 people that consider the Amazon their home - some groups are still uncontacted (see Alternatives).
  • Cattle Ranching: As the world's population gets bigger and richer, the demand for meat is increasing. To rear the cattle increasing tracts of the rainforest are being cleared to make pastures for grazing.
  • Subsistence Farming: Because of the large amounts of poor people that still live in tropical areas, subsistence farming is still widespread. Because rainforest soil loses its fertility quickly after deforestation, the most common form of subsistence farming is slash and burn. With growing populations this method of farming can cause widespread deforestation.
  • HEP: Many of the world's great rivers flow through rainforests e.g. the Amazon. These great rivers often have the most HEP potential. Unfortunately when a dam and reservoir are built it causes damage during construction, but also floods large areas.
  • Mining: With an ever increasing demand for the world's natural resources, countries and companies are looking at increasingly isolated locations, places like rainforests and Antarctica. The rainforests are believed to have many resources including metals and fossil fuels beneath their soils. Gold mining can be particular damaging as mercury is used in its extraction and often runs off into rivers.
  • Road building: Building new roads like Trans Amazon highway from Brazil to Bolivia not only causes deforestation itself, but its also opens up new ares to urbanisation, mining and farming causing further deforestation.
  • Urban growth: With the world population increasing as well as rates of urbanisation increasing many cities like Manuas in Brazil are growing rapidly causing deforestation.
  • Population growth: As populations grow, particularly in countries like Brazil, Peru, India and Vietnam that contain rainforests the demand for land increases, both to grow food and to live.
  • Plantations: Primary products are often seen as an income source for LEDCs, many of who have large areas of rainforest. At the same time with fossil fuels running out, alternative fuels sources are been searched for including biofuels e.g. Palm oil. This has lead to widespread deforestation in countries like Malaysia and Indonesia to plant cops like palm oil.
  • Timber (hardwoods): Hardwoods like mahogany and teak that take hundreds of years to grow are still in high demand to make things like furniture. The extraction of these trees can kills trees around them. Also many countries like China are also demanding large amounts of normal timber that are not always taken from sustainable sources.
  • Hunting: Hunting takes two forms, one form is for bushmeat to feed families and enough the sale of animals either alive e.g. parrots or dead for their skins e.g jaguars.
  • Flooding: Flash floods become more common after deforestation because there is less interception and less root uptake and transpiration. As such rainwater reaches the ground quick, saturating it and causing surface run-off and potential flooding.
  • Landslides: By removing trees and vegetation, you are making the soil less stable. Combine this with saturated ground and the likelihood of floods increases.
  • Biodiversity loss: Because all the species that live in the rainforest are not known it is hard to calculate species loss. However, scientists believe that 1 mammal or bird extinction can be extrapolated to approximately 23,000 extinctions.
  • Reduced photosynthesis: As more and more trees are removed the rate of photosynthesis reduces, releasing more carbon dioxide into the atmosphere and contributing to the greenhouse effect.
  • Silting of rivers: With increased flooding and surface run-off moil soils and silt is washed into rivers, this can not only change local ecosystems (water temperature and clarity) but can also reduce the depth of rivers making navigation harder.
  • Silting of seas and oceans: With the increased frequency of flooding and landslides more silt gets washed into the oceans. The increased amount of silts reduces the transparency of the sea reducing the light reefs receive and the temperature of the water. Increased silt can also block important shipping lanes.
  • Breaking of nutrient cycle: The top soil of rainforests is very thin an receives the majority of its nutrients from rotting flora and fauna. By removing trees you also remove animals and therefore the source of the soils nutrients. With increased erosion the top soil (humus) layer is quickly washed away.
  • Sandification/desertification: Because rainforest soil loses its fertility very quickly after deforestation it quickly becomes hard to grow any vegetation on it, leading to sandification and possibly desertification.
  • Loss of indigenous homes: By clearing rainforests you are obviously destroying the homes of indigenous groups. But also moving close to indigenous groups can spread disease and alter local culture and traditions.
  • Reduced rainfall: Deforestation can lead to reduction in local rainfall because less water is intercepted and transpired from vegetation into the atmosphere reducing the formation of clouds and rainfall.
Map of Biodiversity hotspots - BBC

Ecotourism hopes for Ecuador's tribes - BBC article
Palm oil and deforestation - Independent article

Peru - Brazil Highway to Bring Economic Benefits but at what cost to the Amazon - BBC article

Rate of Deforestation increases in Amazon - BBC article

Amazon Dam Given Go Ahead - BBC article
New Pictures of Remote Tribe Threatened by Deforestation - BBC article

Mining Pollution in French Guiana - Guardian article



Why is Biodiversity Important?


  • Plant biodiversity ensures a varied and interesting diet (more fruits, nuts, vegetables, etc make our diet more interesting and healthier).
  • Greater biodiversity ensures sustainability for all aspects of food webs
  • Biodiversity provides medical remedies for humans, many of which we may not have discovered yet.
  • It ensures the healthy circulation of nutrients in the nitrogen cycle
  • It creates a more diverse and interesting world to live in and promotes ecotourism (natural beauty)
  • Varied ecosystems with high biodiversity are better able to recover from natural and manmade disasters.
  • Creates a diverse gene pool, ensuring continued survival of flora and fauna
  • They can clean water in the hydrological cycle
  • Regulate climate (temperatures and rainfall)




Methods of Protecting Rainforests and Biodiversity


Guyana Rainforest Sale


Guyana located in NW South America is home to some of the world's last reaming virgin rainforest. The Guyanese government has pledged that it wants to protect this rainforest, but its is also very poor and could benefits from its exploitation (logging and mining). Therefore the Guyanese government has proposed a schemes where sections of the rainforest are sold to investors and countries who want to commit themselves to sustainability and carbon neutrality.
One million acres of Guyanese rainforest is up for sale.

As the amount of carbon trading increases and national and international regulations become more strict, countries and companies will increasingly look for ways of reducing their net carbon emissions. Because it is not possible to reduce all carbon emissions to zero, by buying sections of rainforest, it gives countries and companies a chance to reduce net emissions to zero because rainforests are carbon sequesters.

Carbon sequestration: The capture and storage of carbon.

Guyana's Forest Future - BBC

Guyana Rainforest Sale - Independent article


The FSC (The FSC Homepage)


The Forest Stewardship Council is a non-profit NGO that aims to promote sustainable use of the world's forests. It was established in 1993. The FSC aims to achieve sustainable forestry by setting standards for sustainable forestry and certifying sustainable products. By certifying sustainable products, it allows customers to make informed choices. You can recognise certified products by looking for the FSC logo. Although the FSC is supported by a number of large environmental NGOs like the WWF, other like Friends of the Earth have criticised the thoroughness of its certification.

To date 107 million hectares of forest in 78 countries have been certified by the FSC as being sustainable and meeting their guidelines. To become FSC, you have to meet their 10 principles, which include; meeting all national and international forestry laws, respect indigenous groups, ongoing environmental assessments, equitable distribution of profits and the promotion and conservation of natural forests.
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Consumers Must Stop Forest Destruction - BBC article

Sustainable wood may still cause damage - Guardian article


Rainforest National Parks (The Tumucumaque National Park)


The Tumucumaque National Park is located in the Amazon Rainforest in NW Brazil. It was declared a National Park on 23rd August 2002. It is the world's biggest tropical rainforest national park covering an area of 38,874km2. If you include the Guianan Amazonian National Park in French Guiana the protected area covers 59,174km2. The area is very sparsely populated, but rich in biodiversity including rare animals like jaguars and tapirs.

The natural environment is fairly impassable with waterfalls, raging rivers and giant outcrops. As well as known species, it is expected to contain many yet undiscovered species. Although Brazil's national parks are protected by law many still suffer from illegal logging, mining and hunting. The government department in charge of protecting the parks are underfunded and don't even have adequate vehicles to survey the park. However, because the park was designated in conjunction with the WWF, it is hoped that it will receive international funding.

National Parks are very important in attempts to protect biodiversity and indigenous groups, but they can also give rainforests an economic value through tourism. If you kill and animal or fell a tree you only receive money for it once. However, if you can encourage tourists to view the animals and vegetation you can create ongoing income.
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Brazil creates largest rainforest reserve - BBC article
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Other Rainforest and Biodiversity Articles


Indigenous groups protest against dam - BBC article

Brazil Judge blocks Amazon Belo Monte Dam - BBC article

Seeking a solution to Amazon deforestation - BBC article

Climate Deal can't Ignore Rainforests - BBC article

Can Carbon Offsetting Save Rainforest - Guardian article

Climate Change Transforming Rainforests into Major Carbon Emitters, warn scientists - Guardian article

Amazon Could Shrink by 85% due to Climate Change, Scientists say - Guardian article

Bringing Extinct Animals Back from the Dead - BBC article

Alien worm invasion threat to forests - BBC article

Wolf makes comeback in France - BBC article

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