Cold environments

• Cold Environments


  Polar and Tundra
• Polar and Tundra Environments


  • Found in Cold Climates
• Climate in Polar Areas


  • Very cold, normally below freezing
  • Winters tend to drop to -40 °C and can reach-90 C
• Climate in Tundra Areas


  • Also cold
  • Warm months only reach a maximum of 10C
  • Winters can plunge to-50°C
• Precipitation in Polar Areas

  Low-less than 100 mm a year
• Precipitation in Tundra Areas

  Low-less than 380 mm a year
• Seasons in Polar and Tundra Environments


  Well defined-cold summers and even colder winters
• Soil in Polar Areas


  • Ice sheets cover polar areas, so no soil is exposed
• Soil in Tundra Areas

  • Thin, acidic and not very fertile
  • Beneath the thin soil is a layer of permafrost-frozen ground, holding trapped greenhouse gases
• Plants in Polar Areas


  • Few plants-lichens and mosses grow on rocks, and grasses grow on the coast
• Plants in Tundra Areas

  • Hardy shrubs (e.g. bearberry), grasses, mosses and lichens are common
  • Small, short trees may grow in warmer areas
• People in Polar Areas


  • Mostly uninhabited, but the Arctic has some indigenous residents and a few scientists work in Antarctica
• People in Tundra Areas


  • Home to many indigenous people, as well as oil and gas workers in larger towns
• Animals in Polar Areas

  • Polar bears, penguins, whales and seals
• Animals in Tundra Areas

  • Lemmings, wolves and reindeer
• Cold Environments are Fragile, Interdependent Ecosystems
• The biotic (living) and abiotic (non-living) components of cold environments


  Are closely related-many of them are dependent on each other
• The cold climate causes plants to grow slowly and decompose slowly


  This means the soil is relatively low in nutrients, further limiting plant growth
• Herbivores (e.g. reindeer) rely on plants (e.g. mosses) to survive


  They must migrate to areas where plants are able to grow
• In summer, the surface plants absorb heat from the sun


  This prevents the permafrost below from thawing
• Changes to one component of the ecosystem


  Can have knock-on effects on the whole ecosystem
• Humans trample lots of plants

  The soil is exposed to sunlight and warms up, which may thaw the permafrost, eroding soil and preventing plant growth
• With fewer plants to eat


  Animals will struggle to find enough food to survive
• Melting permafrost


  Releases greenhouse gases, which contribute to global warming
• Plants in Tundra Environments

  • Become dormant (inactive) to survive the cold, dark winters
  • Are low-growing and round-shaped to provide protection from the wind
  • Have shallow roots because of the layer of permafrost beneath the soil layer
  • Have small leaves to limit the amount of moisture lost through transpiration
  • Have a growing season of just 50-60 days due to the short, warm summer
• Plants in Tundra Environments


  • Reproduce using underground runners or bulbs to cope with the cold and short growing season
• Animals in Cold Environments

  • Are well-insulated with thick fur or a layer of blubber to reduce energy use for keeping warm
  • Some hibernate to conserve energy and survive the winter
  • Adapt to survive on the limited food sources available
  • Many birds migrate to warmer areas for the winter
• Animals in Cold Environments

  • Grow white winter coats for camouflage
• Cold Environments have Low Biodiversity
• Low biodiversity


  Means when the population of one species changes it can affect the population of dependent species
• Global warming


  Is causing some species to move towards the poles, where it is colder, in response to temperature rises in their natural habitat
• Species already adapted to polar environments

  Can't go anywhere colder, so are at risk of decline or extinction if climate change causes the polar areas to warm up too much
• Alaska


  • A cold environment that's part of the USA
• Development Opportunities in Alaska

  • Oil fields around Prudhoe Bay
  • Mineral resources such as gold, silver, iron ore and copper
  • Fishing industry
  • Tourism
• Challenges to Development in Alaska

  • Small state population
  • Extreme temperatures and weather
  • Inaccessibility due to remote location and poor infrastructure
  • Difficulty providing buildings and infrastructure to cope with either soft or frozen ground and extreme weather
• Cold Environments are Valuable Wilderness Areas Worth Conserving
• Reasons to Conserve Wilderness Areas in Cold Environments

  • They provide habitats for organisms that couldn't survive elsewhere
  • Scientists can study natural environments including landforms, plants and animals that are relatively unaffected by people
  • Studying natural ecosystems may help scientists to replicate the same conditions in managed ecosystems to help preserve rare species
• Cold Environments are Fragile and Take a Long Time to Recover
• Reasons Cold Environments are Fragile

  • Plant growth is slow, so regrowth takes time after damage
  • Species are highly specialised, so find it difficult to adapt to change
• Strategies to Balance Economic Development with Conservation

  • Governments can pass laws to protect designated wilderness areas from development
  • Modern construction methods can minimise environmental impacts
  • International agreements can limit visitors and activities in fragile areas
  • Conservation groups can pressure governments to protect cold environments