people and the biosphere

• biome : areas of the planet with a similar climate and landscape, where similar animals and plants live
• tundra :

  • Far north (60-70º)in the Arctic Circle
  • e.g. Canada, Greenland and coastal Russia
  • harsh cold winters and short summers
  • treeless ecosystems
  • precipitation is extremely low
  • short growing season as the soil is poor, so it lacks a large biodiversity
• taiga :

  • located 50-70ºN (e.g. N.America, Russia and Scandinavia)
  • coniferous forests, which are drought resistant and have cone shaped trees
  • they retain there leaves all year around to maximise the rate of photosynthesis
  • have a longer growing season
  • small animals and migrating birds are present, wolves and bears may also be present
• Temperate deciduous forest :

  • located 40-50ºN and S of the equator (e.g. eastern America, UK and Eastern Australia)
  • have deciduous forests with oak, maple and beech trees
  • hot summers and cold winters
  • moderate precipitaton (75-150cm per year)
  • animals like deers, bears and small animals
• temperate grasslands :

  • located 30-40º N and S of the equator
  • located in Central Europe/Asia/Australia and some parts of South America
  • mostly grass because of the low precipitation too low to support trees and periodic fires
  • low precipitation (25-75cm per year)
  • animals are prairie dogs and originally bison
  • hot summers and cold winters
• desert :

  • located 30º N and S
  • in places like Northern Africa, Australia, Eastern USA, and Middle East
  • precipitation is really low (less than 25cm per year)
  • temp fluctuates (20ºC in the day and 0ºC in the night)
  • mainly cacti and sage bushes as there's low precipitation, which limits the growth of plants, soil is low in nutrients and high in salts
  • nocturnal animals live there, they can regulate there body heat
  • deserts cover 1/5 of the planets biosphere
• tropical rainforests :

  • close to equator (e.g. S. America and South-East Asia)
  • rich ecosystem with over half of the worlds species habitat in the rainforest
  • warm, moist climate around 26ºC
  • precipitation extremely high (200-450 cm per year)
  • has a quick nutrient cycle
  • animals = many insects, reptiles and amphibians
• savannah :

  • located 15-30º N and S (e.g. India, Central/South America and South Africa)
  • temperature stays a little over 20ºC
  • precipitation around 76-150 cm per year
  • dry seasons characterised by wildfires, vegetation has adapted to it
  • often used for animal grazings
  • predators like lions and leapords present and hoofed animals and herds
• local factors effecting biomes :

  • altitude
  • soil and rock type
  • drainage
• altitude = height of the land (height above the sea level)

  • Temperature increases as altitude increases
  • 1000m height increases, the temperature increases by 6.5ºC
• Rock and soil type :

  • When rocks break from erosion/weathering, they release nutrients and chemicals, which influence the pH and fertility of the soil
  • Bedrock influences soil composition and grain size - this affects permeability and vulnerability to erosion and drainage
• drainage = how fast water enters and leaves soil

  • poorly drained soil can be boggy and waterlogged as it retains excess water
  • Some areas receive more water because of their topography
  • Soil type - clay is very porous, so it retains more water, whereas sandy soils are well drained
  • amount of vegetation - more vegetation can intercept and store the water, rather than it all absorbing straight into the soil
  • precipitation - higher temperature = more evaporation, higher rain = wetter soil
• biotic = living factors of an ecosystem (animals and vegetation)
• abiotic = non-living factor of an ecosystem (temperature, humidity and precipitation)
• biosphere is the living layer between the atmosphere and the lithosphere
• biosphere produces :

  • food and water - meat, berries and crops
  • energy sources - fossil fuels and timber for burning
  • raw materials like metal and wood
• services from the biosphere :

  • atmosphere regulation - production and maintenance of gases in the atmosphere for respiration, photosynthesis and greenhouse effect
  • soil formation and nutrient cycle - transfer of plants and food through the soil when animals decompose and then grow into plants
  • the hydrological cycle - movement/purification of water through the biosphere
• indigenous people = earliest known settlers in an area
• greenhouse gases regulate the warmth of our atmosphere
• Carbon sequestration is the process of capturing and storing atmospheric carbon dioxide