Forests Under Threat Flashcards
Where are tropical rainforests?
Evolved at the equatorial climate so have wet weather conditions due to low pressure but also hot temperatures due to concentrated sun beams
What are the 5 rainforest levels?
Herb layer, shrub layer and young trees, under canopy, main canopy, emergent layer
- different species are adapted to each layer
- emergent layer is tallest as they get most rainwater and sunlight
What is the drip tip adaptation?
- mound would grow on all wet surfaces
- this structure allows the leaves to channel water off to prevent rotting
What is the buttress root adaptation?
Large thick roots for stability and balance
- this also means they can absorb more water
- nutrients are concentrated in top layer of soil so these roots must be shallow
How are sloths adapted and wild cats adapted?
- huge claws allow them to hand upside down while their fur grows away from their feet to help shed rain when upside down
- green algae in their fur helps for camouflage from predators
- wild cats have spots for camolfague as the area shifts between brings sunlight and shade due to overhanging trees
What is the rainforest nutrients cycle like?
- the hot damp conditions of forest floors helps with rapid decomposition of dead plant material
- this provides lots of nutrients that are easily absorbed
- yet due to high demand they don’t remained in the soil for long and stay close to the surface
What does Gersheml’s nutrients cycle show?
- 3 places where nutrients are stored (litter, biomass and soil)
- nutrients can enter the soil store from rock weathering and decomposition
- biomass store is huge due to dense vegetation
- litter store is small as decomposition happens faster in warmer climates
- soil store is small as nutrients in the soil are taken up rapidly
What is the tropical rainforest food web like?
- high biodiversity leads to complex food chains as there is loads of different possibilities due to selective eating lead as animals feed particular plants and become pray of others. E.g.b an be both primary and secondary consumers
- variety of tropic levels
What is a food chain?
Represents the succession of organisms that eat another organism and are in turn eaten themselves
-the number of steps an organism is from the start is a measure of its tropic level
How does climate change threaten the tropical rainforest?
- northward shift in atmospheric system could bring constantly dry and hot weather
- animals have adapted to constant temp conditions so can’t tolerate heat spikes so kills some and stresses survivors
- stressed plants and animals have less resistance to disease
- drier forests are at risk of forest fires which TRF is not adapted to
What are direct causes of tropical rainforest deforestation?
- mineral exploitation for example palm oil and coltan/biofuel
- hydroelectric power causes flooding of areas and also clearing of others for access routes, and starving of water downstream
- subsistence agriculture
- cattle farming 60%
- wood and commercial logging
What are the impacts of deforestation in the tropical rainforest?
- loss of habitats and biodiversity
- loss of traditional culture and indigenous tribe land
- less trees to transpire so drought and to regulate gas exchange
- loss of potential medicinal use
- yet, short term economic gains and country can use revenue to develop
What are CITES?
- convention on international trade in endangered species
- currently protects 35000 species and 181 countries that sign up to this agree to stop exports or imports of these species
- provides info
What are pros and cons of CITES?
- cites have a huge international influence (181 countries)
- difficult to check and enforced e.g. poachers still kills rhinos in SA
- requires international cooperation and increases illegal trade as demand stays high
- also doesn’t protect their habitat so they may still go extinct
What is REDD?
Reducing emissions from deforestation and forest degrading
- supports schemes to reduce rate of deforestation e.g. rewarding or paying countries that promote conservation
- the UN monitors the schemes by the use of remote sensing and visits