B: Tropical Rainforests Flashcards
What’s the climate like in tropical rainforests
Same all year round there is no definite seasons
It’s heart (generally between 20–28° C and any varies by a few degrees over the year) because it’s near the Equator the Sun is overhead all year round
Rainfall is very high around 2000 MM per year it rains every day usually in the afternoon
Soil in tropical rainforest
Isn’t very fertile as heavy rain washes nutrients away there any trains at the service due to the Decayed leaf fall for this layer is very thin as because fast in the warm moist conditions
Plants in tropical rainforests
Most trees are evergreen (they don’t drop their leaves in a particular season) to take advantage of the continual growing season
many trees are really tall and the vegetation cover is dense – very little light reaches the fourth floor.
There are lots of epiphytes (plants that grow and other living plants and take nutrients and moisture from the air) eg orchids and germs
Animals in tropical rainforests
Rainforests are believed to contain more animals species than any other ecosystem
Grillers Jaguars anacondas tree frogs and sloths are all examples of rainforest animals
Loads of species of insects and birds many animals are brightly coloured and make a lot of noise
People in tropical rainforests
Rainforests are home to many people have adapted to life that over many generations they make a living by hunting and fishing gathering nuts and berries and green vegetables and small garden plots
Plant adaptations to the rainforest
Buttress roots – support for trees competing for sunlight
Drip tips (thick waxy leaves with pointed tips) – channel the water to appoint so it runs off the weight of the water doesn’t damage the plant no standing water for fungi and bacteria to grow in waxy coating of the leaves also helps repel the rain
Smooth thin bark - no need to protect the trunk from cold temperatures the smooth surface allows water to run off easily
Four distinct layers – emergence only have branches at the crown (when most light reaches them) and plants in the under Canopy have large leaves to absorb as much light as possible
Lianas (climbing plants) – use tree trunks to climb up to the sunlight
Drop their leaves throughout the year – they can go on growing all year round
Animal adaptations to the tropical rainforest
Many animals when there entire lives higher up on the Canopy - strong limbs to climb and leap from trees e.g. Howler monkeys
Flaps of skin – helps them to glide between trees e.g. flying squirrels
Suction cups – for climbing e.g. red eyed tree frogs
Short pointy wings - easily manoeuvre between the dense tangle of branches in the trees e.g. harpy eagle
Camouflage – e.g. leaf tailed geckos to hide from predators
Nocturnal (active at night) – e.g. sloths. They sleep through the day and feed at night when it’s cooler – this helps them to save energy
Low light levels – anteaters have sharp sense of smell and hearing so they can detect predators without seeing them
Swimming – e.g. Jaguars they can cross river channels
Rainforests have a very High?
Biodiversity
What is biodiversity
The variety of organisms living in a particular area - both plants and animals
Rainforests have extremely Hugh biodiversity they contain around …….% of the worlds plant animal and insect species
50%
May contain around half of all life on earth
Rainforests are stable and productive environments because it’s hot and wet all year round. Therefore plants and animals don’t have to
Cope with changing conditions and there is always plent to eat
Many organisms have evolved to depend on just a few species for survival -
They are very specific to a particular habitat and food source and many species are only found in a small area
What is likely to lead to the extinction of many species and the loss of biodiversity?
Deforestation (cutting down trees) and unctrolled development of the rainforest
Number of endangered s cues in Brazil increased from 218 in 1989 to 628 in 2008
Why are tropical rainforest chopped down
Population pressure Mineral extraction Energy development Commercial loggoing Commercial farming Substitandw farming
What’s population pressure deforestation
As the population in an area increases, trees are cleared to make land for new settlements
What’s mineral extraction within deforestation
Minerals (eg gold and iron ore) are mined and sold to make money
What energy development to do with deforestation
Building dams to generate hydro electric power floods large areas of forest
What’s commercial logging to do with deforestation
Trees are felled to make money. Road building for logging also requires more tree clearance
What’s commercial farming to do with deforestation
Forest is cleared to make space for cattle grazing or for huge palm oil or soya plantations
What’s substance farming to do with deforestation
Forest is cleared socfarmers can grow food for themselves and their families
General environmental impacts of deforestation
No trees to hold soil together - heavy rain washes away the soil (soil erosion) this can lead to landslides
Without a tree canopy to intercept (catch) rainfall and tree roots to absorb it, more water reaches the soil. This reduces soil fertility as nutrients in the soil are washed away out of reach of plants
Trees remove CO2 from the atmosphere also burning vegetation to clear forest produces CO2 so deforestation means more CO2 in atmosphere, which adds to the greenhouse effect deforestation is resposnislbe for at least 15% of all global CO2 emissions each year - more than all the worlds annual transport emissions combined
General economic impacts of deforestation
Logging farming and mining create jobs
A lot of money is made from selling timber mining and commercial farming
In the long term, deforestation can destroy the resources that countries depend on eg timber and reduce attractiveness of the area to tourists
The livelihoods of some local people are destroyed cause deformation can cause the loss of the animals and plants that they rely on to make a living
What is the rate of deforestation
Is very Hugh
Rougjyly 300 000 km^2 per year from 2000-2010
Globally rate seems to be slowing down but there are still hotspots where it’s increasing eg Borneo and Nigeria
OverLl deforestation in Brazil and Indonesia accounted for almost half of the global total between 2001 and 2014 though Brazil has reduced its deforestation rate since 1990
Case study for deforestation?
Amazon
How large is the Amazon compared to others
It’s the largest on the earth - covering an area of around 8 million km^2
Since 1978 over how much km^2 has the Amazon been destroyed by deforestation?
750 000km^2
Caused of deforestation in the Amazon between 200-2005
65-70% commercial (cattle) ranching
20-25% small scale subsistence farming
5-10% commercial farming - mostly soy farming but rice corn and sugar cane also
2-3% logging - lots of illegal logging. New roads have opened up areas of forest which were previously hard to get too
1-2% other activities eg mineral extraction road building energy development and new settlements
What puts pressure on the Amazon rainforest
Population growth and migration
Brazilian government offers land in the rainforest to poor people from overcrowded cities
There are many more small scale subsitence farmer now and people who have no land or whose land had become unproductive are opening up more areas of the forest
Environmental impacts of Amazon deforestation
Amazon stores around 100billion tonnes of carbon - deforestation wil lrealsed some of this as carbon dioxide which causes global warming
Brazil is losing 55 million tons of topsoil every year because of soil erosion caused by soy farming
Economic impacts of the deforestation of the Amazon
Brought wealth to countries the were poor
Farming makes a lot of money for countries in the rainforest eg in 2008, Brazil made $6.9 billion from trading cattle it is also the worlds clsecond biggest exporter of soy beans
The mining industry created jobs for loads of people eg Buenaventura mining company in Peru employs over 3100 people
Logging contributes a huge amount to Brazil’s economy
Local Brazilian rubber tappers who extract natural rubber from rubber trees have lost their livelihood as trees have been cut down
