Amazon

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  • Amazon
    • Location
      • Either side of the equator in south America
      • 78% in Brazil, smaller areas in places such as Peru, Colombia, Ecuador
      • covers about 7.3 million sq km
    • Biome characteristics
      • Climate
        • mean temperature is about 26 degrees
        • 2677mm of rainfall each year
          • well distributed around the year
        • reproduction all year round
          • natural selection and evolution takes place quicker
      • Flora
        • primary productivity high due to high concentration of light
        • Most biologically diverse ecosystem in the world
          • at least 80,000 species of which 40,000 are important globally for regulating  climate
            • eg Brazil nut
      • fauna
        • 430 species of mammals
          • eg pink river dolphins or spider monkeys
        • developed over a long time leading to complex food webs
        • growth not restricted by water supply
    • Spatial variations
      • 80% is rainforest
      • western amazon  experiences no dry season
        • higher species diversity
      • by rivers such as Madeira there are swamp forests
        • trees are lower and wider apart
      • Different ecosytems within a biome increase overall diversity
    • plant  adaptations
      • Canopy trees
        • umbrella shape crowns, increase surface areas to get maximum sunlight
        • straight and thin trunks to conserve energy
      • Emergent trees
        • smaller leaves
        • reduce transpiration
        • greener because cells contain more chlorophyll to maximise photosynthesis
      • Thin bark of 1-2mm
        • protection of low levels not needed
      • shallow tree roots
        • Mineral nutrients are rapidly recycled
          • plants don't need to look far for nutrients
      • spines instead of leaves
        • less water lost by transpiration
        • repel insects
    • Animal adaptations
      • Toucan
        • strong large bills to prise open fruit and crack seeds
      • Sloth
        • opposable thumb allows it to hang from trees
          • protection
          • can reach a greater volume of nutrition
      • camouflage
        • anaconda snake has green and black markings so that it blends in with foliage
      • bright colours
        • poison dart frog is bright red
          • warn predators that its highly dangerous
    • threats
      • up to to 1960 habituated by sustainable indigenous
        • little impact on the biome
      • 1960's government encouraged colonisation
        • sponsored large scale projects to exploit resources that aided development
          • 17% of the original forest has been lost
      • deforestation
        • Cattle ranching
          • 80% of the deforestation
        • soya bean agriculture
          • thrives in rainforest climate
        • hydroelectric dams
          • eg Belo monte
            • flood 400km2
        • logging
          • take timer from land that has been cleared for cattle
          • destroyed nutrient cycle
          • increase co2 levels
      • oil and gas extraction
        • Colombia
      • gold mining
        • Brazilian state of para
      • hunting
        • birds, reptiles and mammals
      • drought 2005, 2010
        • forest fires
  • drought 2005, 2010
    • forest fires

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