P1 tropical rainforests Flashcards

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1
Q

where are tropical rainforests found ?

A
  • cover 2% of the earths surface
  • home to half of the worlds plants and animals
  • found in a broad belt close to the equator from south America in the west
  • through west Africa to southeast Asia and Australia in the east
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2
Q

what are the 5 physical characteristics of tropical rainforests

A

-climate
- water
- soil
- people
- plants and animals

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3
Q

Describe the climate in a tropical rainforest

A
  • tropical rainforests thrive in the equatorial climate, experiencing high temperatures (27 deg)
  • high rainfall throughout the year (2000 mm per year)
  • creates ideal growing conditions and accounts for the lush vegetation growth
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4
Q

how is water a physical characteristic of a tropical rainforest

A
  • experience a distinct wet season
  • high rainfall lasting months
  • excess water on the ground, swelling local rivers and sometimes causing flooding
  • water will soak into the soil, dissolving and transporting away nutrients-> called leaching
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5
Q

Describe the soils in tropical rainforests

A
  • rainforest soils are not very fertile
  • nutrients are very concentrated in the upper topsoil and are quickly taken up by plants as they grow
  • in response, trees have shallow roots to maximise their use of these vital nutrients
  • intense leaching removes nutrients from the topsoil and redeposits them further down
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6
Q

how are people a physical characteristic of a tropical rainforest

A
  • traditional tribes living in rainforests live in harmony with the natural environment.
  • hunting and gathering only what they need to survive
  • this is a sustainable system
  • increasingly people are exploiting the rainforests for commercial gain
  • chopping down trees for timber or to make way for ranching or commercial plantations
  • extremally harmful to the rainforest ecosystem as habitats are destroyed
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7
Q

how are plants and animals a physical characteristic of a tropical rainforest

A
  • rainforest have the highest level of biodiversity in the world
  • there are thousands of species of plants and animals
  • birds live in the canopy high above the forest floor, feeding on seeds and nectar from flowing plants
  • mammals, such as monkeys and sloths are well adapted to love in the trees
  • snakes use the trunks of trees as vertices highways from the forest floor to the canopy above
  • animals such as deer and rodents browse on vegetation from the forest floor
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8
Q

how is the tropical rainforest interdependent

A
  • the tropical rainforest ecosystem is a fragile environment
  • it is easily damaged by peoples activities and can take a long time to recover
  • its survival depends on a close interdependence between its complex parts
  • if one component is removed e.g trees are removed through deforestation - harmful knock on effects will threaten the survival of the entire ecosystem
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9
Q

what is nutrient cycling

A
  • the vast majority of nutrients are stored in the biomass
  • the soil contains few nutrients, as any nutrients released by decomposers are quickly absorbed by the trees and plants or leached into the soil by heavy rainfall
  • there are few nutrients in the litter store, as decomposers, thriving in the warm and wet conditions, quickly break down dead leaved and branches
  • there are rapid transfers of nutrients indicated by thick arrows. this is hugely to do with climate conditions; for example warm and wet conditions promote chemical weathering
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10
Q

what are plant adaptations

A
  • the vegetation, and animals, are well adapted to the climate conditions experienced within each layer
  • access to sunshine is a key factor promoting strong vertical growth, as shown by the emergent trees punching through the canopy exploiting maximum sunlight
  • lianas grow around and between the tree trunks to get as much light as possible for growth
  • drip tips help get the water that is intercepted by the canopy to the forest floor where it can infiltrate soils
  • buttress roots helps to anchor the trees to the shallow forest floor
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11
Q

what are animal adaptations

A

-due to the intense competition for food, animals have become adapted to live of specific plants or animals that few others eat. for example toucan and parrots have strong beaks for cracking hard nuts
- bats thrive of the fruits growing in the canopy, which they can reach by flying, they also help to disperse seeds
- animals also use colour to act as a camouflage or to warn predators e.g poison dart frog
- three toed sloth to help them crawl up trees where they live the majority of time

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12
Q

why are there high levels of biodiversity in rainforests

A
  • wet and warm climate encourages a wide range of plants and trees to grow, providing many habitats for animals
  • the rapid recycling of nutrients speeds up plant growth (producers) and provides food fir consumers
  • many parts of tropical rainforests are untouched by people, enabling a range of plants and animals to thrive
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13
Q

what are the threats to biodiversity in tropical rainforests

A
  • with the exception of natural events such as lightening strikes(fires), floods, and disease, the greatest threats come from people
  • unsustainable timber harvesting
  • development of roads and settlements
  • slash and burn agriculture, creating commercial plantations
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14
Q

what are the main issues associated with biodiversity decline

A

keystone species: a species that has multiple connections with other species. as it a multiple food source, there could be serious knock on effects if its number decline.
-indigenous tribes being unable to survive in rainforest and having to abandon there traditional lifestyle
- plant and animal species may become extinct
- important medical plants may become extinct

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15
Q

how is the rate of deforestation changing in the amazon rainforest

A
  • despite the previously high levels of deforestation, from 2004 deforestation has reduced significantly
  • the main reason is the action plan implemented by the Brazilian government in 2004
  • however since the change in Brazil’s government in 2019 there has been renewed deforestation in the amazon and rates are set to increase rapidly
  • scientists are concerned about a potential ‘carbon bomb’ if the burning continues
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16
Q

what are the 6 causes of deforestation in the amazon rainforest

A
  • subsistence farming and commercial farming
  • logging
  • road building
  • mineral extraction
  • energy development
  • settlement and population growth
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17
Q

how is subsistence farming and commercial farming a cause of deforestation in the amazon rainforest

A
  • indigenous rainforest tribes practise subsistence farming
  • recently land has been cleared for commercial farming
  • in Brazil, cattle ranching account for 80% of deforestation
  • soy beans, palm oil and sugar cane (for biofuel) are the major crops
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18
Q

how is logging a cause of deforestation in the amazon rainforest

A

-trees such as mahogany and teak are used for furniture
- smaller trees are used for fuel, pulped or made into charcoal
- Malaysia is one of the largest exporters of tropical wood
- 80% of deforestation in Malaysia is for logging

19
Q

how is road building a cause of deforestation in the amazon rainforest

A
  • roads bring supplies and provide access to new mining areas and settlement
  • in brazil the trans-Amazonian highway stretches for 4000 km
20
Q

how is mineral extraction a cause of deforestation in the amazon rainforest

A
  • in Brazil many minerals such as gold and copper are mined extensively, causing huge scars in the landscape and polluting the rivers
21
Q

how is energy development a cause of deforestation in the amazon rainforest

A
  • high rainfall creates ideal conditions for HEP and there are several large dams and reservoir’s
  • in Brazil, the belo monte dam (opened in 2019) is a huge hydro-electric power complex, the second largest in the country. in damming the xingu river, a tributary of the amazon, over 400,000 hectares of rainforest have been flooded and 20,000 local people displaced
22
Q

how is settlement and population growth a cause of deforestation in the amazon rainforest

A
  • settlements have developed to service the developments in the Brazilian and Malaysian rainforests
  • such as farming and mineral extraction
  • this has lead to an increase in population
23
Q

what is the impact of economic development on deforestation

A
  • mining and commercial farming generate employment and tax for the government
  • taxes can be used to improve education and social conditions
  • hydro electricity provides cheap renewable power, boosting industrial development
  • improved infrastructure opens up new areas for economic development and settling etc
24
Q

what is the impact of soil erosion on deforestation

A
  • soil erosion is a major issue in many countries
  • once land is exposed due to deforestation, the soil is much more vulnerable to the torrential rain
  • without the roots to hold it together the loose soil can be easily washed away
25
Q

what is the impact of climate change on deforestation

A
  • at the local scale, tropical rainforest retain and emit moisture to the atmosphere
  • when large areas of rainforest is cut down, the climate becomes drier
  • high levels of evaporation from leaves and branches cools the air
  • when rainforests are cut down this cooling process stops and the air becomes warmer
  • trees are important ‘sinks’ for co2
  • when trees are burned, carbon is released back into the atmosphere, enhancing the greenhouse effect and contributing to global warming.
26
Q

what are the 5 reasons why rainforests are valuable to people

A
  • resources
  • medicine
  • indigenous tribes
  • energy
  • employment
27
Q

what are the 5 reasons why rainforests are valuable to the environment

A
  • water
  • biodiversity
  • climate
  • climate change
  • soil erosion
28
Q

how does the rainforest provide resources for people

A
  • tropical rainforests are rich in reserve wood, nuts and fruit as well as minerals
  • items such as bananas, cocoa and sugar come from rainforests
29
Q

how does the rainforest provide medicine for people

A
  • 25% of all medicines come from rainforest plants
  • more than 2000 plants have anti-cancer properties
  • less than 1% of rainforest plants and trees have been tested for medicinal qualities
30
Q

how are indigenous tribes valuable to people

A
  • thousands of people live in harmony with the rainforest
  • there lives depend on maintaining a healthy ecosystem
  • e.g the Achuar tribe in peru numbers over 11,000
31
Q

how does the rainforest provide energy for people

A
  • high rainfall totals in rainforests create the potential for hydro-electric power
  • electricity can provide much needed light and power for local people
    -local micro-hydro systems can serve isolated communities
32
Q

how does the rainforest provide employment for people

A
  • rainforests provide employment opportunities in tourism for guides or stewards
  • other opportunities exist in construction, farming or mining
33
Q

how does the rainforest provide water for the environment

A
  • rainforests are important sources of freshwater
  • 20% of the worlds freshwater comes from the amazon basin
34
Q

how does the rainforest provide biodiversity in the environment

A

tropical rainforests contain 50% of the worlds plants and animals, including thousands of types of species

35
Q

how does the rainforest provide a good climate for the environment

A
  • known as the lungs of the world
  • rainforests contribute 28% of the world oxygen
  • moisture emitted through transpiration feeds into the water cycle and prevents the climate from becoming to dry
  • evaporation of water from rainforests helps to cool the air
36
Q

how does the rainforest provide climate change for the environment

A
  • rainforests absorb carbon dioxide from the atmosphere
  • acts as a carbon sink
  • this helps offset global warming
37
Q

how does the rainforest provide soil erosion for the environment

A
  • rainforests shelter and bind together the tropical soils
  • this prevents harmful soil erosion which can silt up rivers and reservoirs
38
Q

what is sustainable management of a rainforest

A

establishing an environmental balance, enabling the rich resources to be used without causing any long term damage to the ecosystem

39
Q

how is selective logging and replanting a sustainable management strategy of rainforests

A
  • individual trees instead of clear felling of lots of trees
  • officials monitor the logging to ensure that it is done legally and correctly
  • new trees are planted to ensure the system is sustainable
40
Q

how is conservation and education a sustainable management strategy of rainforests

A
  • countries have designated areas of rainforest as national parks
  • large international organisations have supported conservation projects in exchange for carrying out scientific research
  • international charities such as the WWF or birdlife support conservation and education programs by promoting it in schools
41
Q

how is ecotourism a sustainable management strategy of rainforests

A
  • often encouraged in tropical rainforests and it has become widespread in countries such as costa rica
  • sustainable form of tourism
  • supports local communities, employing indigenous people as guides
  • by focusing on nature it offers local governments a financial return for preserving rainforests rather than cutting them down
42
Q

how is international agreements about the use of hardwoods a sustainable management strategy of rainforests

A
  • the FSC promotes sustainable management by approving timber for sustainable sources
  • suppliers are encouraged to only buy timber with the FSC stamp
  • the international tropic timber agreement prevents the trade in hardwoods by only marking timber with a registration mark if it is from a sustainably managed forest
43
Q

how is debt reduction a sustainable management strategy of rainforests

A
  • most countries with tropical rainforests are LICs or NEEs
  • to promote development some take out large loans which they now find hard to repay
  • some HICs have agreed to write of debts in return for rainforests being protected
  • E.G the USA decided to convert a Brazilian debt of 13.5 million into a fund to protect areas of rainforest