Paper 3 : Forests Under Threat Flashcards
Name all structures of the tropical rainforest
Emergents
Canopy
Under canopy
Shrub layer
Name characteristics of the emergent layer
Trees as tall as 60 metres
Animals - birds, bats and gliders
Receives lots of bright sunlight + plenty of rain
Name characteristics of the canopy layer
Deep layer of vegetation - fruits, seeds etc.
Animals - insects, birds, monkeys, frogs, sloths
Home to 90% of animals in the rainforest
Name characteristics of the under canopy layer
Warm , damp sheltered layer
Grows large leafed shrubs suited to warmth, shade and moisture
Low light conditions
Buttress roots
These stretch up from the ground and help to anchor the tree to the ground
Lianas
Woody vibes that start at ground level, and use trees to climb up to the canopy where they spread from tree to tree to get as much light as possible
Drip tips
Waxy leaves with drip tips - these shed water quickly to prevent the leaves from rotting
Epiphytes
Grow upon other plants and evolved to get all nutrients from water and air rather than soil
What are the main threats to the tropical rainforest?
Hydroelectric power Roads Mining Cattle ranching Crop farming Logging
What are the main consequences of drought?
Ecosystem stress
Forest fires
What are the reasons for deforestation?
Growing population Mineral extraction Construction of power and energy sources Logging and timber Farming and agriculture
Why are tropical rainforests at risk?
Economic development
Demand for resources
Poverty
Debt
Why is hydroelectric power a threat to the rainforest?
Needed to produce electricity
Also helps control flooding
Why are roads a threat to the rainforest?
Divide up parts of the forest and can cut off connections between different systems
Why is mining a threat to the tropical rainforest?
The Amazon includes bauxrite, iron, ore manages, gold, silver, and diamonds
Why is cattle ranching a threat to the tropical rainforest?
Brings money into the country and provides food and jobs for country’s growing population
Why is crop farming a threat to the tropical rainforest?
Provides food for rainforest communities and the landless poor of Brazil
Why is logging a threat to the tropical rainforest?
Tropical hardwoods such as ebony and mahogany can be sold for a good price abroad
Why is economic development causing tropical rainforests to be at risk?
Forests are cut down for roads, buildings, hydroelectric power dams and cities
Why is debt causing tropical rainforests to be at risk?
Cutting down forests can help countries to sell hardwoods for good money
Helps clear debt to rich countries
Brazil borrowed money to cut down forests - needs to pay back
Why is poverty causing tropical rainforests to be at risk?
People cut down parts of the forest to farm crops for food - survival
Only way to make a living
Why are demand for resources causing tropical rainforests to be at risk?
Tropical rainforests contain raw materials needed by countries
This involves part of the rainforest being destroyed
Resources used for everyday products
Land is needed to feed growing populations
Name two indirect threats to the tropical rainforest
Climate stress
Global warming
Explain how tropical rainforests are threatened by an indirect threat
Climate stress - rising temperatures from climate stress cause drought which can cause forest fires to break out, burning trees and litter, and releasing carbon dioxide
Major droughts are drying the leaf litter so decomposer organisms die out, threatening the nutrient cycle
Name the indirect threats to the Taiga
Wildfires
Acid rain
Pests
Why are wildfires a threat to the Taiga?
Summer storms generate lightning strikes
Pine needles which litter the floor is perfect tinder for wildfires to start
Coniferous trees have sticky resin which burns easily
Why is acid rain an indirect threat to the Taiga?
Fossil fuels are burnt in power stations to make energy - releases SO2 and NO into atmosphere
SO2 and NO react with water + oxygen to form acids + then fall as acid precipitation
When acid rain falls into lakes + soils, it kills insects + their eggs which reduces food supply for birds
Acid rain also kills the soil + means less nutrients enter the soil which makes plants less resistant to forest fires + disease
Why are pests an indirect threat to the Taiga?
Increase of pests:
Reduces commercial value of the forest, preventing it being sold as timber
They dramatically alter the ecosystem
They change the landscape to a more open landscape with fewer trees
Give one example of a particular pest that has affected Taiga
White pine blister rust - a fungal disease that attacks white pine trees, prevents them from regrowing
Explain how climate change has affected the biodiversity of the Taiga biome
Wildfires - caused by summer storms, generate lightning strikes, causing a reduce in biodiversity and stopping the regeneration of species
Pests - Taiga winters usually kill of pests but in recent years, an increase of pests has reduced the commercial value of the forest, preventing it being sold as well as dramatically altering the ecosystem
What type of trees are in the taiga forest?
Evergreen trees
What features of evergreen trees make them well-adapted to taiga forests?
Have needles instead of leaves - This reduces the surface area of the leaf and means that less water is lost from the tree
Cone shaped trees - The shape means that they do not store much snow on their leaves/branches. If too much snow built up on the trees then they could break
Taiga forest are highly….?
Interdependent