Tropical Rainforests

Describe the climate

Consistent all year.
No seasons.
Wet and warm - humid.

Average temperature

28 degrees C

Average rainfall

>2000mm per year

Describe the soil

- Infertile
- Some nutrients on the surface (decomposition)
- Latosol - red as rich in iron.

Why is the soil infertile?

Leaching of nutrients from heavy rain.

Name the 4 layers of the rainforest

- Emergent
- Canopy
- Understory
- Forest Floor

Describe the biodiversity

>50% of all the worlds species.
High risk from deforestation.

Describe the plants

Evergreen - continual growing season.
Tall trees.
Dense canopy (blocks light).

Describe the nutrient cycling

Very rapid due to hot and humid conditions.

Describe 'drip tip leaves' adaptations

Waxy leaves shaped like a funnel.
- encourages run-off
- reduces water damage + rotting

Describe 'lianas' adaptations

Woody creepers root to ground and wind around trees.
- use trees to climb to get sunlight + nutrients

Describe 'epiphytes' adaptations

Grow on branches of tall trees.
- better access to sunlight in canopy
- don't waste energy + resources as they don't have to grow tall

Describe 'buttress roots' adaptations

Roots spread over a wide area.
- so trees are more stable
- tree can access more nutrients from poor-quality soil

Describe the 'poison dart frogs' adaptations

Bright coloured skin which excretes poison.
- warns predators not to eat it
- so have adapted to look poisonous but aren't

Describe the 'spider monkeys' adaptations

Prehensile tail with 23 vertebrae.
- grasp on tree branches
- hang, swing and pick fruit with it

Describe the 'chameleons' adaptations (rainforests + hot deserts)

Change the colour of their skin and swivelling eyes.
- camouflage to predators and stand out for mates
- pinpoint fast-moving prey

Name the 7 causes of deforestation and the percentages

- Farming (cattle ranching + soybean production) 65-70%
- Subsistence farming 20-25%
- Logging 2-3%
- Road building (TransAmazonian Highway 4000km)
- Mineral extraction
- Energy development
- Population growth

Name 3 impacts of deforestation

- Soil erosion (-100 tonnes of topsoil per hectare/yr)
- Economic development
- Climate Change

Name 7 sustainable management strategies that decrease the rate of deforestation

- Selective logging
- Replanting (afforestation)
- Conservation
- Education
- Ecotourism
- Debt reduction
- International hardwood agreements

Key facts of the Amazon Rainforest

- In South America
- Largest area in Brazil
- Produces 1/5th of oxygen

Why is the rainforest important to people?

- 25% of all medicines
- Reasources
- Indigenous tribes

Why is the rainforest important for the environment?

- >50% of all species in the world
- Trees absorb carbon
- 20% of world's freshwater
- 28% of world's oxygen