geography spring revision 2025

• whats an ecosystem

  a natural area in which plants and animals and other non-living things are linked together to form a natural system
• define biotic

  a living element eg animals,plants etc
• define abiotic

  a non-living element eg. water,light,temp etc
• define producer

  eg. grass uses sunlight to produce food
• define consumer

  a living element that gets energy by eating other producers eg rabbit eats grass or other consumers eg fox eats rabbit
• distribution of ecosytems

  *90 degrees N -polar- extremely cold anf mostly ice covered

  *+60 degrees N - Tundra- very cold,long winters short summers,very dry, mosses grasses and shrubs grow there with permafrost underneath

  * near equator- Tropical rainforest- hot and wet all year around, drense lush forest

  *between 15 and 30 degrees N and S- hot deserts- very hot at day but cold at night,very little rainfall, shrubs and cacti grow in the sandy soil
• what are primary consumers

  consumers that eat producers eg. grass
• what are secondary consumers

  consumers that eats herbivores eh foxes eat rabbits
• define adaptation

  the features that plants or animsals need to evolve to survive in their specific invironment eg. buttress roots
• whats interdependence

  withing the ecosystem the biotic components depend on eachother and abiotic components such as food,water and shelter for survival
• define decomposers

  organisms that get energy by breaking down dead plants and animals eg. bacteria and fungi
• how does epping forest show interdependence

  its shown through the life cycle of trees:

  1. nutrients in the trees convert to humus for healthy soil
  2. the sol is then ready to support the growing tree
  3. in spring the tree grows broad leaves so that photosynthesis is maximised for summer
  4. by mid-autumn these leaves fall down to the ground level where decomposers break down the dead leaves
  5. the cycle repeats- decomposers,producers and abiotic elements (the sun) areall reliant on eachother here.
• whats a food chain

  a diagram of animals and plants showing which eats which
• whats te climate of the TRF

  hot and wet all year round- around 2000mm rainfall annually
• describe the soil of TRF

  poor thin soil because all the nutrients are either absorbed for plant growth or washed out becasue of heavy rain
• whats leaching

  when heavy rainfall washes out the nutrients in the soil
• what are the 4 layer of trees in TRF

  emergent- 50m tall- where birds rest

  canopy-30m where alot of animals live eg. sloths

  undercanopy- 15m- any gaps caused by falling canopy trees are quickly filled

  shrub layer- very dark and damp
• what is the nutrient cycle

  its a cycle including

  • biomass-all living elements
  • which then falls to the ground as litter
  • -then all dead animals and plants are then converted to nutrients for vegetation by decomposers eg. bacteria and fungi
  • the cycle continues
• what impact does change have on ecosytems


  all aspects of the ecosystem have to be balanced, if one component changes it may well have a knock on affect on the rest of the ecosystem
• how do changes happen to ecosytems

  human causes;

  -deforestation

  -hunting for animals

  -introduction to alien species

  natural causes;

  -climate change

  -leaching

  -diseases

  -wildfires
• what issues are threatening the TRF biodiversity

  • Agriculture, particularly large scale slash and burn 
  • Mining
  • Hydroelectric power
  • Logging
  • Road building and settlements
  • Wildfires
• why does deforestation reduce TRF biodiversity

  becuse plants and animals there have adapted to the very niche conditions there so wouldnt respind wellto change
• what are the environmental impacts of deforestation

  1. reduces biodiversity- inhabitants lose their homes, die in the process or find a home elsewere
  2. soil eroision- the mass removal of trees means that the soil can easily become loose and erode away
  3. climate change- deforestation limits the absorption of CO2 meaning temperature rises and moisture decreases so a hotter drier atmosphere
• what are the economic gains of deforestation

  1. development of land for mining creates jobs eg. farmer
  2. companies pay taxes to government which can then be used for education and better water supply
  3. hydroelectric power provides cheaper energy
  4. valuable mineral extracted by mining eg iron ores,copper etc
• what are the econimic losses of deforestation

  1.polluted waters-may cause diseases and deaths

  2. rising temperatures mean harder worl for farmers

  3.plants with medicinal benefit may go extinct

  4. tourism decreases

  5. more costly to adapt to the drier and hotter world
• causes of deforestation- logging

  -largest exporter of wood in 1980s

  -clear felling - hoping all the trees down in one area was common

  -is now replaed with selective logging
• causes of deforestation- roadbuilding

  -roads and projects are being made to access deeper into the forest and mining areas
• causes of deforestation- hydroelectric power development

  dam's supply energy for malaysia

  dam resevoirs flooded over 700km*2 of forest- soil leached
• causes of deforestation- mineral extraction

  forest cleared for mining

  drill for oil and importatnt minerals
• causes of deforestation- population growth

  the higher the population the more companies need to mine and tree fell because they need to provide more homes, energy and roads

  -people encouraged to move to countryside from rapidly growing cities
• causes of deforestation- commercial farming

  farmers receive 10 years of less tax for more land of plantation

  -maaysia is the biggest exporter of palm oil
• causes of deforestation- substance farming

  • This can sometimes involve slash and burn where areas are cleared using fires - these can sometimes get out of control and destroy large areas of rainforest
• what are two NGOs that help to protect the rainforest

  • birdlife international
  • WWF
• what are NGOs

  organisations that work independaently and discuss social and politaical issues
• ways to manage TRF sustainbly- local

  -education

  -ecotourism

  -use non-harmful technology eg solar panels
• ways to manage TRF sustainably- international

  • laws being put out to help reduce selective logging
  • tropical hardwood agreement 2006
  • nature swaps instead of paying debt
• ways to manage TRF sustainably- national

  • create protected areas
  • stopping developers
  • educate people about the effects
• characteristics of hot deserts

  • less than 250mm of rainfall annually
  • very hot in the day but very cold at night
  • cacti and shrubs grow there
• affect of hot desert climate on vegetation

  • can be fertile as nutrients havent been leached away
  • limited vegetation because of little rainfall and hot climate
  • little organic matereal because of the little vegetation
• how have plants adapted to the hot deserts climate

  cacti

  • they are succulent meaning they store water in their tissue
  • the spikes are to prevent consumers

  flowering plants

  • make brightly coloured flowers to attract insects

  tap roots

  • grow deep into the soil to reach water supply