PowerPoint Presentation by h6xKdfjN

VIEWS: 2 PAGES: 14

									Types of Forests
                       Tropical
                     (Rainforests)
   Canopy is often closed (little light reaches
    below)
   A canopy opening happens when a tree falls
       Plants competing for the light fill the space
   Many trees are covered with epiphytes
       Epiphyte- plants that grow on other plants instead
        of in the soil
   Rainfall determines the vegetation growth rate
Rainforests of the Earth
Rainforest Mammals
Rainforest Birds
Rainforest Reptiles and others
             Coniferous Forests
   Has cone bearing trees (pine, spruce, fir, and
    hemlock)
   Also called temperate rain forests
   Warm, moist air from the pacific ocean supports these
    unique communities
   They are usually dominated by one or a few species
    of trees
   The Taiga is the largest terrestrial biome on earth
   Receives heavy snowfall but the cone shape of the
    trees prevents branches from breaking
   Currently, they are being heavily logged.
Taiga
           The Northern
            Coniferous Forest
            stretches from
            North America to
            Eurasia.
           The southern
            border of the artic
            tundra is called
            the TAIGA.
Taiga Pictures
               Temperate Deciduous
   Dense stands of trees
   Occur where there is enough moisture to support
    growth of large trees
   More open than rain forests, but not as tall
   Has distinct vertical layers
   Mammals in these forests hibernate and some migrate
    to warmer climates
       Deciduous- plants that drop their leaves before winter
            This is done because temperatures are too low for photosynthesis
        Deciduous Trees and Winter
                Dormancy
   Deciduous trees begin to lose their leaves
    when temperatures begin to get colder and
    the days become shorter
       Circadian Rhythm- a 24 hour cycle that
        organisms internally live by
         What causes leaves to fall?
   This happens in 3 steps:
    1.   Cells die at the base of each leaf because of forming cork
         that cuts off the water and nutrients for the leaf
    2.   Green chlorophyll turns to other types of chlorophyll that
         can use sunlight better
          –   Xanthophylls: yellow light
          –   Carotenoids: yellow and orange light
          –   Anthocyanins: scarlet and purple light
    3.   Leaves fall to the ground
          –   This prevents trees from being damaged because of freezing
              temperatures and strong winds
          –   The tree remains dormant in the winter until longer days and
              warmer weather cause new leaves to grow

								
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