People and the Biosphere

• Biosphere


  -the part of the planet where life is found
• Biomes


  - large scale ecosystem (desert or tropical rainforest)
• Biotic


  - living things including vegetation (flora) and animal (fauna) life
• Ecosystem


  - Interaction of biotic components with their environment, the abiotic components
• Deciduous Trees


  - Trees that lose all their leaves of part of the year
• Abiotic


  - the non-living environment (rocks and rivers)
• Diurnal


  - during the day
• Coniferous trees


  - leaves which don't fall off
• Latitude

  - distance from the equator measured in degreed (a global factor)
• Atmospheric belts

  -alternating areas of low and high pressure on Earth as a result of global circulation patterns
• Altitude

  -how high above the sea level you are
• How do Animals/plants and the atmosphere interact?

  -Cattle add methane to the atmosphere

  -Trees photosynthesise adding oxygen to the atmosphere
• 2 Global factors affecting biome distribution

  -Latitude which affects solar radiation and sunshine hours

  -Atmospheric pressure belts which affect rainfall
• 3 Local factors which affect biome distribution

  - Altitude

  - Rock and soil type

  -Drainage
• How does latitude affect biomes and ecosystems?

  Temperatures drop the further you are from the equator due to the curvature of the earth
• How does latitude affect biomes and ecosystems closer to the poles?

  The sun is at a lower angle in the sky so heat is dispersed over a large area and sunlight has a thicker area of atmosphere to pass through as it shines obliquely through the atmosphere
• How do animals/plants and rocks/soil interact?

  -Rocks get broken down by biological weathering

  -Animal dung/leaf litter act as fertiliser for soil

  -More fertile and less rocky soil allows more vegetation growth so more food for animals
• How do plants and the water cycle interact?

  -trees intercept and absorb moisture reducing surface run off

  - Transpiration by plants return moisture to the atmosphere

  - The amount of water available affects what species can survive in an area
• How does latitude affect biomes and ecosystems closer to the equator?

  The sun shines directly overhead so the heat is more intense and shines at a right angle through the atmosphere

  so it has less distance to travel through thick atmospheric gases
• How do low pressure belts affect biomes?

  Low pressure=rain

  It is found at the equator (0and at 6) North and South of the equator.

  In these areas air rises, cools, condenses and forms rain
• How do high pressure belts affect biomes?

  High pressure=dry

  High pressure is found around 30and 90North and South of the equator.

  In these areas air sinks, moisture is evaporated and no clouds are formed
• What global factors influence biome location?

  Temperature and sunshine hours- these are mainly controlled by incoming solar radiation due to the latitude of a place

  Precipitation- controlled mainly the high- and low-pressure bands due to the Earths atmospheric circulation
• Why are tropical rainforests hot and wet?

  The sun's rays that reach the earth near equator have a small area of the earth and atmosphere to heat than rays reaching the earth at higher latitudes. It is therefore hotter at the equator than at higher latitudes.
• Why are deserts hot and arid?

  The presence of dry, descending air and high pressure

  Theres a lack in moisture as theres less evaporation. There are also less clouds to reflect the sunlight away. With no evaporative cooling and a
• How does the biosphere provide food for people?

  Indigenous people forage for food e.g. nuts or hunt meat. Others grow food
• How does the biosphere provide building materials for people?

  Trees and other plants can be used as building materials

  e.g. pine from taiga forests, bamboo from tropical forests
• How does the biosphere provide medicine for people?

  Plants species in tropical rainforests have been used to create over 7000 drugs

  Aspirin from willow tree for blood thinning and pain relief

  Chemicals from coral reefs used to treat some cancers
• How does the biosphere provide fuels for people?

  Indigenous people use wood/moss/ dried grass/ dried animal dung as fuel

  In area with little vegetation animal fat is used as fuel for oil lamps

  Developed nations use plant oil to make Eco fuels for cars
• How are humans exploiting the biosphere for commercial gain in energy?

  Forest are cut down crops to make biofuels

  Areas of forest are flooded for hydro-electric dams

  Drilling for oil and gas in the tundra-pipelines melt the permafrost
• Why are demands increasing for energy?

  Demand increases as population increases and gets wealthier as more people have electronic devices
• How are humans exploiting the biosphere for commercial gain in water?

  Water used for washing land

  Water resources being over exploited especially underground stores

  Damage to water supplies= damage to wildlife
• Why is Demand increasing in water?

  Increase in population and increase in wealth. Manufacturing goods use A LOT of water. Urbanisation means more people have water on tap
• How are humans exploiting the biosphere for commercial gain in minerals?

  Because demand increases more mines are needed

  Mines in tropical rainforests- deforestation and toxic chemicals washed into rivers killing wildlife
• What was the Malthusian theory?

  Population grows faster than resource supply. When population outstrips food supply there's a point of catastrophe and things live starvation war and disease will reduce population size to a point where we have enough resources
• Who made theories on managing resources and supply?

  Thomas Malthus

  Ester Boserup
• What was Ester Boserup theory?

  As resources become limited people have the incentive avoid future catastrophe which invents ways of getting more resources.
• How are humans exploiting the biosphere with minerals?

  demand increases, more mines are needed.

  Mines in tropical rainforests - deforestation AND toxic chemicals washed into rivers killing wildlife
• How does the biosphere help maintaining soil nutrient?

  Plant roots and animals help maintain soil structure and fetility

  Roots hold soil together preventing erosion

  Vegetation intercepts rainfall preventing leaching
• How does the biosphere help regulating the water cycle?

  Water is intercepted and taken up by plants so less reaches rivers preventing flooding and soil erosion
• How does the biosphere help regulating the environment?

  Plants take in CO2 and give out oxygen and animals do the opposite

  Maintaining CO2 balance in the atmosphere which is important to life preservation and prevents global warming and ocean acidification