Geog Paper 3 Knowledge Organiser

• Biosphere

  The layer of the Earth's surface between the lithosphere and the atmosphere, containing all living organisms
• Major biomes

  • Tropical rainforest
  • Taiga
• Biomes

  • Their location and characteristics are influenced by temperature, precipitation and sunshine, all controlled by latitude
  • Local factors can alter the biome distribution (rock and soil type, water availability, altitude)
• Components of biomes

  • Biotic (living) part - plant and animal life
  • Abiotic (non-living) part - atmosphere, water, rock and soil
• Ecosystem services provided by biomes

  • Provisioning services (goods) - food, fuelwood, timber, chemical materials
  • Supporting services - nutrient cycling, photosynthesis, soil formation
  • Regulating services - carbon storage, hydrological cycle
  • Cultural services - tourism, education, science, well-being
• Biomes are usually carbon sinks


  They maintain healthy air, soils and the hydrological cycle
• Destroying biomes

  Releases additional carbon dioxide into the atmosphere, contributing to global warming
• Removing biomass from biomes

  Takes away nutrient stores, reducing soil health
• Destroying forest biomes- Deforestation


  Reduces interception and infiltration, affecting groundwater supplies, increases surface run-off and erosion, and flooding becomes more frequent
• Burning forests

  Turns them into carbon sources
• Population growth, industrialisation, urbanisation and rising wealth has led to an increase in demand for natural resources, resulting in biome destruction, species threatened, and pollution
• Population growth has been slowing down (not declining) since 1962, and is now approximately 1.1% per annum
• Malthusian view


  The population will grow, and the planet will run out of resources, leading to 'positive checks' (war, famine) or preventative checks (fewer children)
• Boserupian view


  Humans will invent new ways to allow more resources to be supplied (for example, technology such as farm machinery, GM crops and irrigation)
• Tropical rainforests

  • High biodiversity due to equatorial climate, species evolution over millions of years, and multiple vegetation layers
  • Adaptations include hardwood trees with buttress roots, lianas, birds with strong beaks, and primates with prehensile tails
• Nutrient cycling in tropical rainforests

  • Rapid due to large biomass store, small litter store, large nutrient uptake, large nutrient supply, and large nutrient loss
• Deforestation of tropical rainforests


  Disrupts the nutrient cycle, changes the climate with rising temperatures and more rainfall reaching the ground, and causes litter and soil erosion
• Farming often fails in tropical rainforests as the soil contains few nutrients
• Taiga climate and biodiversity

  • Harsh climate, low biodiversity, adaptations include thick fur, hibernation, migration, and coniferous evergreen trees
• Nutrient cycling in taiga

  • Slower than in rainforests, with smaller stores and flows, most nutrients in the litter due to slower decay, and smaller biomass store
• Threats to tropical rainforests

  • Deforestation - cattle ranching, poverty, debt, development, demand
  • Climate change - droughts, reduced decomposition, food web impacts, switching from carbon sink to source
• Threats to taiga


  • Deforestation - paper, construction, mining, fossil fuels, hydroelectric power
  • Wildfires, pests and diseases, acid rain
• CITES


  An international treaty that protects endangered species, but does not prevent deforestation and global warming
• REDD


  A UN project that aims to stop deforestation by funding conservation projects, but is difficult to police so illegal logging often takes place
• Acid rain


  Burning of fossils releases sulphur dioxide into the air - the acid rain weakens trees by reducing photosynthesis and damaging the soil
• Conservation and sustainable management of tropical rainforests is vital if goods and services are not to be lost for future generations
• Main global actions to protect rainforests

  • CITES (The Convention on International Trade in Endangered Species)
  • REDD (Reducing Emissions from Deforestation and forest Degradation)
• CITES


  An international treaty adopted by 180 countries that protects species (for example, African elephants and the banning of the ivory trade)
• Protecting species does not prevent deforestation and global warming
• REDD


  A UN project that aims to stop deforestation with governments and TNCs funding projects to conserve forests in development countries
• It is difficult to police REDD so illegal logging often takes place
• Sustainable management of tropical rainforests

  • Has economic, social and environmental benefits
  • Ecotourism provides jobs for local people and educates tourists
  • Agroforestry maintains biodiversity allowing crops to grow between trees
• Population growth will increase urbanisation and deforestation
• There are pressures to develop the taiga for oil, gas and mineral extraction, and HEP
• Wilderness areas and national parks

  • Ways of protecting the taiga such as those in the USA
  • RAMSAR is an example of conservation that adds an additional level of protection for wetlands
• Some people believe that the taiga should be conserved; others believe it should be exploited
• National governments must try and balance these views which can lead to conflict (for example, indigenous people versus oil and gas companies)
• The economy versus the environment debate is common in all biomes but is especially notable in the Taiga and TRF
• Selective logging


  Only removes the large valuable trees and leaves some of the forest intact
• Energy resources classified into three main categories

  • Non-renewable - finite resources (fossil fuels), once used up, they cannot be replaced (for example, coal, oil and gas)
  • Renewable - infinite resources, they will never run out (for example, wind power, solar power and hydroelectric power)
  • Recyclable - energy sources that can be reused (for example, nuclear and biofuel energy)