Forest under threat

• What are abiotic factors?

  non-living things
• What are biotic factors?

  living things
• how are biotic factors dependent on abiotic factors?

  1. if the is no sun photosynthesis cannot take place therefore no food can be produced, so no chance of survival.

  2. if there is no soil then plant can't get he nutrients so cannot move onto a further stage.

  3. if there is no water, no chance of survival

  4. no air means no trees and no living organism
• how are abiotic factors dependent on biotic factors?

  1. if there are no decomposing organisms then the soil won't be nutritious

  2. if there are no trees then there will be too much carbon dioxide in the atmosphere, can cause problems
• name three plant adaptations in the TRF

  1. buttress roots

  2. stratifies layers - small plants and large trees - different plants and animals are adapted to each layer.

  3. drip tips
• explain drip tips as a plant adaption

  -located in the canopy layer

  -water runs off them quickly

  -means heavy rain doesn't cause leaves to break away
• explain buttress roots as a plant adaption.

  -rainforest trees have 'buttress' structures as their base

  -keeps tree upright, provides stability

  -tall, slender trunks

  -used because the rainforest's nutrients are concentrated in the top level of the soil so trees don't need deep roots

  -and are tall to maximise sunlight
• explain stratified layers as a plant adaptation.

  -sunlight is a big challenge in the TRF

  -dense forest canopy block out light, emergents (trees such as Kapoks) are fast growing tall trees to compete other trees for sunlight.

  -lots of competition on the forest floor for nutrients in the soil and sunlight shining through. plants called epiphytes grow and live on branches high in canopy to seek sunlight and they obtain nutrients from water and the air rather than the soil.
• name three animal adaptations in the TRF.

  1. monkey's hands and feet + tails +colour vision

  2. eagles legs

  3. insects camouflage
• explain how monkeys hands, tails and vision have evolved as an animal adaptation in the TRF.

  -hands and feet have evolved for gripping, used to travels through the trees to find fruit

  -tails have evolved to be long, used to balance.

  -evolved colour vision, used to identify ripe fruit
• explain how insects have evolved as an animal adaptation.

  -insects use camouflage to mimic sticks and leaves, their surroundings.

  -used to avoid being eaten by the predator (eg chameleons)

  - chameleons have feet that are adapted to grip branches and a tail that it can wrap around branches to hang from trees.
• explain why the rainforest has a very high rate of nutrient cycling. -supports high levels of biodiversity and complex food webs

  -heavy convectional rainfall (happens when hot air rises and cool air falls)

  -high humidity

  -plants grow all year in huge numbers

  -dead matter drops to the forest floor and decomposes quickly in the warm wet conditions.

  -the constant precipitation leaches nutrients down through the deep rainforest soil.

  -nutrient-rich soil and fast growing plants take up the nutrients very quickly.
• what does a very high rate of nutrient cycling support?

  -high levels of biodiversity

  -complex food webs
• productivity

  the rate of biomass generation - how quickly plants grow
• define biodiversity.

  The number of animals and plants (species) in a given area.
• define food web.

  The range of animals and plants in a given area.
• Taiga plants have to deal with low temperatures, a very short growing season and low nutrient soils.

  name four plant adaptations in the taiga of the needle-shaped leaves of the trees.

  1. needles have a very small Surface area means they lose much less water than the broad leaves in the TRF

  2. leaves have a waxy coating to prevent them from losing water and damage by frost.

  avoids the leaves dropping to maximise photosynthesis throughout the year.
• explain why the trees in the taiga are cone-shaped. (plant adaptation).

  many taiga trees have branches facing downwards to shed heavy snow to avoid breaking.
• name four animal adaptations in the taiga

  1. thick coats

  2. smaller ears and tails

  3. hibernation

  4. winter camouflage
• explain thick coats as an animal adaptation in the taiga

  -thick fur coats used for insulation in cold conditions
• explain smaller ears and tails, claws, large feet as an animal adaptation in the taiga

  -smaller ears and short tails avoids frostbite

  - sharp claws which can demolish burrows of small animals and fishing for salmons

  - large feet distribute body weight and provide grip on ice.
• explain ability to hibernate as an animal adaptation in the taiga

  -the brown bears build up fat layers in summer for hibernation in winter dens

  -allows the animals to survive a long period of time without food
• explain winter camouflage as an animal adaptation in the taiga

  -winter camouflage (white coat)

  -so they don't stand out to predators in the white snow

  -also white fur provides better insulation than dark fur in the cold conditions

  often non migrating animal species

  migrating animals - south for warmer winters
• why does the taiga have a lower productivity, less nutrient cycling and very low biodiversity?

  -litter store is mainly made up of pine needles which are tough to decompose

  -litter accumalates due to the slow rate of decomposition, only happens in summer.

  - soils are thin, low in nutrients and acidic (from the pine needles) so plants grow very slowly. harsh conditions - short growing season, frozen winters, low precipitation

  
  

  eg species of coniferous trees and simple, low level plants like mosses, lichens and fungi
• describe the characteristics of the taiga's nutrient cycle.

  -biomass store is very small (cold and dry)

  -litter store is the biggest store (little decay)

  -uptake of plants is very little (little nutrients to take up)

  -all transfers between stores are generally low
• describe the characteristics of the TRF's nutrient cylcle.

  -biomass store is very large, biggest store (warm and wet)

  -litter store is very small (lots of decay in warm and wet conditions)

  -uptake of plants is relatively big (lots of nutrients to absorb)

  -transfers between stores are relatively high
• name the five causes of deforestation

  1. commercial hardwood logging

  2. subsistence agriculture and fuelwood

  3. commercial agriculture, growing biofuels e.g palm oil

  5. mining for mineral resources

  6. electricity (hydroelectric power dams)
• name the three things that contribute to deforestation.

  1. demand for biofuels

  2. demand for mineral resources

  3. demand for electricity (HEP)
• explain how commercial hardwood logging is a cause for deforestation.

  -cutting trees for sale as timber or pulp.

  -The timber is used to build homes, furniture, etc.

  -The pulp is used to make paper and paper products.
• Why is a lot of illegal TRF commercial hardwood logging still going on.

  DEMAND-high demand for products such as rosewood means people will pay very high prices for the timber

  POVERTY-many people living near rainforests are poor and commercial hardwood logging pays well.

  CORRUPTION-police and government officials will often let illegal commercial hardwood logging happen in return for money
• explain subsistence agriculture is a cause of deforestation.

  -when farmers grow food crops to feed themselves and their families.

  -trees are cut down on a small plot and the undergrowth is then burned

  -then crops are planted

  -SOON the nutrients in the soil are leeched out and weed growth takes over.

  -the farmer will usually decide to clear another plot

  -this is also known as 'slash and burn
• why is the 'slash and burn' method so populand why could this beome a problem

  -it makes sense to very poor families as it doesn't cost any money to clear the land

  -as the population grows in developing countries rapidly, it means that many more people are clearing the rainforest

  -third of all rainforest deforestation is caused by subsitence farmers
• explain what commercial agriculture is and why it is a cause of deforestation

  -large areas of land are cleared for the commercial use to grow crops and animals (eg cattle farming, palm oil, sugar canes)

  meat in high demand, increasing population

  palm oil used in many products, in high demand
• why is commercial agriculture the leading cause of deforestation

  -beef is one of brazils' key exports (key for economic growth)

  -most of the deforestation in brazil over the last 20 years was due to cattle farming (75% of the deforestation)
• explain local demand for fuelwood as a cause of deforestation

  -people living near rainforests, or in them, use them as a source of fuel.

  -rainforests are a major source of charcoal, which is an important source of fuel in many African cities

  - as population increases, rates of deforestation have also rapidly increased due to more demand
• explain mining and HEP as a cause of deforestation

  -some rainforests are on top of valuable minerals which industrialisation has increased demand for.

  - it is often most economic to use open-cast mining to extract the minerals and the rainforest is totally destroyed to dig.

  -area of land has to be cleared to mine and also for the road leading to the mines

  -more roads then encourage more miners, loggers and farmers to move in.

  -15% of all deforestation is due to mining and road building

  - HEP electricity production supports industrialisation, urbanisation and economic development. dams built floods and totally destroys the land.
• name and explain the one indirect threat to the TRF.

  climate change: global warming may bring less rainfall and increased drought and hotter temperatures to the rainforest. distinctive dry season.

  species unable to adapt die out

  vegetation unable to survive wildfires, from being drier.

  species that are adapted to a seasonal forest would out compete rainforest species.

  stressed plants and animals have less resistance to diseases.
• define climate change.

  a long-term change in the earth's climate, especially changes in temperature
• define direct threats

  deliberately cutting down trees for timber and other uses.
• define indirect threats

  non deliberate threats to the health of the rainforest including pollution, disease, climate change.