Living World (RAINFORESTS) Flashcards
What is a tropical rainforest?
A warm, wet ecosystem located within the tropics
What is rainfall like in tropical rainforests?
- Extremely high rainfall
- Rainfall exceeds 2000mm per year
- Usually seasonal rainfall (6 months)
- Very humid
What is temperature like in tropical rainforests?
- High temperatures (26-27°C)
- Consistent temp throughout the year
- Sun shines directly on equator throughout the year, explaining consistency of climate
What are the soils like in tropical rainforests?
- Very infertile and nutrient deprived (due to leaching)
- Soil is called latosol
- Thin layer of nutrients from decay of dead organisms at the top layer
Why are soils so nutrient deprived?
- Nutrients are washed away and dissolved by intensive rainfall (LEACHING)
- So a soil called LATOSOL is left behind (infertile, iron-rich soil)
What is the nutrient cycle in tropical rainforests?
- Vegetation and trees rapidly grow and shed leaves
- Vegetation decays and decomposes rapidly
- These nutrients enter the topsoil and are either
absorbed by plants or washed away by rain, so nutrients to not penetrate to deeper soils - Shallow roots take up the nutrients on the forest floor and use them to grow
- Cycle continues
Where can tropical rainforests be found?
Between the tropics -
- South-East Asia
- Central Africa
- Northern Australia
- South America
- Central America
What are the characteristics and layers of tropical rainforests?
Lush and dense
- Emergent Layer
- Canopy Layer
- Understory Layer
- Forest Floor
Climate of tropical rainforests summarised
- Hot, temps average 27°C
- Wet, rainfall over 2000m per year
- Humid
- Wet season lasts around 6 months
Leaching
Where heavy rainfall dissolves nutrients and carries nutrients away from the soil
Adaptations of plants in rainforests
- Leaves have flexible bases so they can turn and face the sun
- Drip top, to allow excess water to drip off
- Thin, smooth tree bark allows water to quickly flow down
- Epiphytes live on branches high up to obtain sunlight and extracting nutrients from air and water
- Buttresses, which are massive ridges to support the base of tall trees
Causes of deforestation in Malaysia
- Logging (trees cut for timber)
- Road building for access to mining areas (tin) and new settlements
- Energy development
- Subsistence farming
- Slash and burn to clear space
- Commercial farming (Malaysia is the world’s largest palm oil exporter)
What is clear felling?
Where all the trees in an area are cut down destroying the forest habitat
What is selective logging?
Where mature trees only are cut down, and trees with ecological importance are left unharmed
Impacts of deforestation
- Soil erosion
- Loss of biodiversity
- Climate change
- Economic development
Economic gains of deforestation
- Improved transport
- Hydroelectric power
- Minerals (gold)
- Palm oil industry benefits
- Jobs created
Economic losses of deforestation
- Water pollution may lead to shortages
- Fires can cause pollution and burn out of control which cost money to fix
- Climate change may have great effects of industries, eg. Certain crops may struggle to grow in different climates which would have negative effects economically
- Tourist numbers decrease
Before and after - Area covered by rainforests
Before - 15.5 million km^3
After - 6.2 million km^3
What did Brazil do to reduce deforestation in 2004?
- Government crackdowns
- Consumer pressure not to use products gained from deforested areas
Reasons why tropical rainforests should be protected
- Biodiversity
- They are carbon sinks
- Produce 28% of the world’s oxygen
- Prevent climate from becoming too hot and dry
- Potential medicines
- Resources are finite
Ways to sustainably manage rainforests
- Selective logging and replanting
- Conservation and education
- Ecotourism
- International agreements
What are some international agreements to protect rainforests?
- Sustainable hardwood forestry promoted by the international FSC
- Debt reduction where lenders reduce debts in exchange for agreement that rainforests will NOT be deforested
