GCSE Geography "The Living World" ; Tropical Rainforests

KEY CASE STUDY! (For this topic.)

Amazon Rainforest, Brazil, South America.

General TR: Density location

• Found in close proximity to the Equator

• Found in regions like South America, Southeast Asia and West Africa.

General TR: Climate

An equatorial climate;

• High temperatures (around 27 degrees on average all year round.)

• High rainfall ( around 2000mm of rainfall on average all year round.)

General TR: Water

• Water = Distinct wet season (lasts about half a year.) with high rainfall.

• Impacts on other parts of TR = Excess water can cause nutrient leaching to occur, causing soil to be infertile.

General TR: Soil

• Soil = Latosols topsoil (red coloured, iron-rich soil) is formed due to rapid nutrient leaching.

• Impacts on other parts of TR = Due to high nutrients concentration, plants have adapted by developing shallow roots systems.

General TR: TR Layers

• TR have high biodiversity levels due to the large range of habitats available in the layers of the TR. Some examples include;

  • Ground layer = Rodents ,e.g. Agouti (0m - 20m)

  • Undercanopy = Lizards, e.g. Panther Chameleon (20m - 30m)

  • Canopy = Climbing animals, e.g. Howler Monkeys (30m - 40m)

  • Emergent = Birds, e.g. Toco Toucan (40m ≤)

General TR: Plant adaptations

Some key plant adaptations are -

• Epiphytes = Specially adapted plants capable of growing on other vegetation to grow themselves;

  • Lichens = Plants capable of growing tree barks and rocks.

• Rainforest trees (e.g. the Kapok tree) = Have a number of adaptations in order to maximise growth;

  • Wide and waxy leaves = Maximises photosynthesis while ensuring surface run-off of rainfall.

  • Smooth bark = Allows for surface run-off of rainfall to take place.

  • Buttress roots = Specially adapted tree roots which spread over a wide area and penetrate deep in soil to maximise nutrient absorption.

General TR: Animals adaptations

Some key animal adaptation are -

• Camouflage = Allows animals to avoid predators.

• Flight = Allows for easier mobility through TR.

• Adapted limbs = Allows for easier mobility through TR.

• Nocturnal = Allows animals to conserve energy.

Amazon Rainforest; Biodiversity comparison

• The entirety of the Amazon contains around 16,000 types of tree species.

• In comparison, the entirety of North America has around 700 types of tree species.

General TR; Reasons for biodiversity

Some of the reasons for such a biodiversity are-

• Lack of human interaction

• Climactic conditions

General TR; Threats and issues with biodiversity

Some of the threats to the TR’s biodiversity are - PIA

• Agriculture (“Slash-and-burn” methods)

• Infrastructure (Deforestation demands)

• Pollution (Global warming)

Some of the issues with these threats are - FE

• Forced relocation of local inhabitants.

• Extinction of animal and plant species.

Amazon Rainforest; Causes of deforestation

Some of the key causes of deforestation are - REMPS

• Road building = The construction of the Trans-Amazonian Highway created an estimated 5 million hectares of deforested land.

• Energy development = The construction of the Belo Monte Dam in the Xingu river caused 40,000 hectares of rainforest to be flooded.

• Mineral extraction = The continuous expansion of the Carajas mine has cleared tens of hundreds of millions of trees.

• Population growth = The growth of demand for tree-based products from a growing population (0.61% at 212.64 million as of 2024) has contributed to increased reliance of felling.

• Substinence farming = Cattle ranching of the Amazon contributes to 80% of all its deforestation (1.5 million hectares per year in total.)

Amazon Rainforest; Rate of deforestation

The rates can be seen in the following;

• 1990s-2000s: High deforestation; (~20,000-30,000 km²/year), peaking at 27,000 km² in 2004.

• 2004-2012: 70% drop; Due to government interventions (e.g. the Action Plan), lowest at 5,000 km²/year by 2012.

• 2012-2018: Stabilization; Fluctuating around 6,000-8,000 km²/year.

• 2019-2021: Sharp increase; ~10,000 km² in 2019, peaking at 11,000 km² in 2020 due to relaxed regulations.

General TR: Impacts of deforestation

• Some of the impacts are -

  • Economic impacts = More positive.

    • Improved infrastructure

    • Increased job opportunities

    • Cheaper utilities, e.g., cheap hydroelectricity

  • Environmental impacts = More negative.

    • Increased soil erosion due to higher exposure to torrential rain.

    • Increased CO2 emissions due to more trees being burnt.

    • Drier climate due to decreased rates of evotranspiration due to less trees. (Can also lead to increased number of forest fires.)

General TR: Importance of the TR to the World

Some of the key reasons are -

1) To People =

a) Medicine; 25% of all medicines come from the TR.

b) Resources; 37% of global coal reserves in Southeast Asia alone are in TR’s.

c) Indigenous tribes; Achuar Tribe, Peru = A group of tribespeople who rely on the TR for natural resources; made up of 10,000 people.

2) To the Environment =

a) Water; 20% of the world’s freshwater supply comes from the Amazon Basin.

b) Climate; 30% of the world’s oxygen supply comes from TR’s.

c) Biodiversity; TR’s contain around half of the world’s biodiversity.

General TR; Sustainable Management methods

Some key sustainable management methods include - CIDSE

1) Conservation =

• Givaudan (a TN perfume corporation) which exchanges the conservation of parts of the Amazon in Venezuela for large volumes of tonka beans with Conservation International.

2) International Agreements =

• The “International Tropical Timber Agreement” restricts the trade of unlicensed hardwood on the market to reduce illegal deforestation; involves 55 countries (29 producers, 25 consumers.)

3) Debt reduction =

• “Debt-for-nature swapping” agreements, e.g. between U.S.A relieving Brazil of £13m of debt in exchange for the protection of large parts of the Amazon .

4) Selective logging =

• The Malaysian Selective Logging Management System (40 year monitoring plan) = Has allowed for more sustainable and legalised logging of their TR to take place.

5) Ecotourism =

• Santa Lucia Cloudforest Reserve, Ecuador = Has reduced the environmental effect of tourism, e.g. eco-lodge construction, while making it more beneficent to locals, e.g. the reserve employs over 6,000 people