sustaining ecosystems

• human activities that impact the polar system

  • tourism
  • fishing
  • indigenous people
  • mineral extraction
  • whaling
• Antarctica: Characteristics

  features: land mass is covered in 99% ice sheets, and sea freezes in winter which causes the continent to double in size

  flora: moss, lichen, sea contains phytoplankton

  fauna: whales, seals, birds, penguins
• The Arctic: Characteristics

  features: mostly ocean with drifting ice and mountainous regions, permanently covered in snow

  flora: low-growing shrubs, lichen, moss

  fauna: whales, seals, wolves, reindeer, caribou and polar bears
• human activities that have impacts on the rainforest

  • logging
  • agriculture
  • mineral extraction
  • tourism
• nutrients in rainforest soils

  1. the hot wet climate means that chemical weathering is rapid, meaning there is a deep layer of soil above the bedrock
  2. leaves fall all year round, so there is a constant supply of dead leaves, forming a thick leaf layer
  3. this is quickly broken down to form humus which then gets mixed into the soil
  4. the layer of humus is thin because the high density, fast growing plants quickly absorb the nutrients
  5. nutrients are leached (washed downwards) through the soil by the heavy rainfall, making the soil nutrient poor
• nutrient cycle

  1. trees are evergreen, so dead leaves and other materials fall all year round
  2. the warm, moist climate means that fungi and bacteria decompose the dead organic matter quickly releasing nutrients into the soil
  3. rainwater soaks into the soil and the nutrients are dissolved in the water
  4. dense vegetation and rapid plant growth mean that the nutrient-rich water is taken up by the plants roots
• tropical rainforest

  • the sun is usually overhead, so it is hot meaning evaporation rates are high.
  • high evaporation rates mean there's lots of water vapour, so rainfall is high
  • vegetation is dense, so lots of water is intercepted and stored by plants
• ecosystems


  meaning: all living and non-living organisms in an area

  biomes

  • tundra
  • grassland
  • temperate forest
  • tropical forest
  • desert