Unit 2 -- Biome Notes

BIOMES

• What is a Biome
  • Biomes: large regions characterized by a specific climate and types of plant and animal communities.
    • Biomes are described by their vegetation
    • Plant adaptations:
      • 1.  Size
      • 2.  Shape
      • 3.  Color
    • Climate: average weather conditions in an area over a long period of time.
      • 1.  Two most important factors that determine climate:
        • a.  Temperature
        • b.  Precipitation
    • Temperature:
      • 1.  Most organisms adapt to live within a particular range of temps and
        • a.  Cannot survive too far above or below their range.
        • b.  Biomes that receive frequent rainfall will have denser vegetation, support large trees, support a wide variety of larger animals
        • c.  Biomes where rainfall is not frequent will have cactuses and desert shrubs.
• Forest Biomes
  • Tropical rain forests: forests or jungles near the equator.
    •  characterized by rain and little variation in temp
    • They help regulate world climate
    • nutrients are within the plants
    • Decomposers break down dead organisms and return the nutrients to the soil
    • plants absorb the nutrients.
    • Some trees support fungi.
      • 1.  fungi transfer the nutrients from the dead matter to the tree.
  • Rain forest Biomes
    • different types of plants grow in different layers.
    • four main layers of the rain forest:
      • 1.  Emergent Layer
      • 2.  Upper Canopy
      • 3.  Lower Layer
      • 4.  Understory
    • emergent layer: top foliage layer
      • 1.  reaching heights of 60 to 70 m (197-230ft)
      • 2.  Animals:
        • a.  Eagles
        •  b. bats
        •  c.  monkeys
    • Canopy: layers of treetops that shade the forest floor
      • 1.  primary layer
      • 2.  absorb up to 95 percent of the sunlight.
    • Understory: foliage layer beneath and shaded by the main canopy of a forest.
      • 1.  Little light allowing only trees and shrubs adapted to shade to grow there.
      • 2.  Most plants do not grow more that 3.5 m tall. (11ft)
      • 3.  Species:
        • a.  diverse vegetation has led to the evolution of diverse  animals
        • b.  Animals
          • *  animals use specific resources in particular ways to avoid competition
          • *  adapted to capture prey and avoid predators.
        • c.  Insects
          • *  use camouflage to avoid predators
          • *  Example: may be shaped like leaves or twigs.
• Threats:
  • Every minute, 100 acres of rainforest are cleared for logging operations, agriculture, and oil exploration.
  • Exotic-pet trading
  • native people are threatened by habitat destruction.
• Taiga
  • Taiga: region of evergreen, coniferous forest below the arctic and subarctic tundra regions.
    • long winters and little vegetation.
    • growing season is about 50 days
    • Animals:
      • 1.  Migratory birds
      • 2.  Insects
      • 3.  Shrews
      • 4.  Snowshoe Hares
• Savanna
  • Savannas: plains full of grasses and scattered trees and shrubs
    • found in tropical and subtropical habitats
    • have a wet and a dry season.
      • 1.  Many animals are only active during the wet season.
    • Grass fires help to restore nutrients to the soil during the dry season.
• Temperate Grassland
  • Temperate grasslands: communities dominated by grasses, have few trees, and have hot summers and cold winters,
    • most fertile soil of any biome
    •  Few natural temperate grasslands remain due grazing areas and farmland
    • Animals:
      • 1.  grazing animals
        • a.  bison
        • b.  antelope
      • 2.  prairie dogs
      • 3.  owls
      • 4.  badgers
• Chaparral
  • Chaparral: temperate woodland biome with vegetation
    • includes broad leafed shrubs
    •  located in areas with hot, dry summers and mild, wet winters.
    • located in the middle latitudes
  • Threats to Chaparral:
    • human development.
    • develop lands because they get sun, near oceans, and have a mild climate year round.
• Desert
  • Deserts: regions that have little or no vegetation, little rain, and extreme temperatures.
    • there are hot and cold deserts
    • located near large mountain ranges
      • 1.  mountains prevent precipitation.
• Tundra
  • Tundra: treeless plain
    •  characterized by very low winter temperatures, short, cool summers, and vegetation that consists of grasses, lichens, and perennial herbs.
    • Permafrost: frozen layer of soil or subsoil
  • Tundra
  • Threats:
    • food chains are simple so they are easily disrupted.
    • Oil has been found and is being extracted from these areas
      • 1.  Pollution from oil spills or leaks