Post on 14-Dec-2015
Coniferous Forests
• Also called boreal forests or taiga– Also called the spruce-moose forest
• Found across the northern portion of N. America, Europe and Asia – Between the grasslands and the tundra
• No taiga in the Southern Hemisphere
Coniferous Forests
• Long, extremely cold winters with 6-8 hours of sunlight
• Short, cool summers with 19 hours of sunlight
• Annual precipitation (both rain and snow) 14-30”.
Coniferous Forests – Animals
• Populations are scarce, mostly herbivores– Large herbivores
• Reach high into trees or dig into deep snow
– Seed eaters• Pull seeds from cones• Eat fallen seeds on the
ground
• Carnivore size varies– Lynx, wolf
Coniferous Forest - Plants
• Primarily conifers– Also called evergreens
– Stiff needles instead of leaves
– Cones shaped seed cases
• Cones must open to release the seeds
Conifers - Facts
• Adaptations– Needles– Color– Shed their needles slowly– Decrease competition through chemical defense
Temperate Forests - Facts
• Also called deciduous forests– drop leaves completely every winter
• Found in eastern N. America, western Europe and eastern Asia
• Long, very warm summers
• Cold winters (not severe)
• Forest soil is thick and very fertile
Deciduous Forest - Structure
• Stratified– Canopy
– Understory
– Shrub layer
– Ground cover
– Litter layer
Deciduous Forest - Animals
• High biodiversity– Includes:
• Birds
• Small and large herbivores
• Small and large carnivores
• High degree of resource partitioning
Deciduous Forest - Plants
• High biodiversity from canopy to ground
• Canopy is primarily deciduous trees – Includes maples,
birches and oaks
Plant Adaptations
• Leaves – broad and flat for maximum photosynthesis
• Excess carbohydrates made during photosynthesis is stored in the sap
Plant Adaptations
• Daylight shortens – Trees prepare to lose their leaves.– Chlorophyll is removed from the
leaves
– Tubes connecting the leaves to the stem close
– Leaves begin to dry
– Leaves fall – leaving only the branches exposed to winter snow, ice and wind
Plant Adaptations - Seeds
• Seeds can’t grow in shadow, so they must be dispersed.
• Done by:– Brightly colored fruit
– Hard shells
– Wings
Forests – Tropical Rainforest
Tropical Rainforests - Facts
• Found along or near the equator– Amazon River (S. America), Indonesia, Africa
and Central America
– Currently covers about 2% of the earth’s land surface
– Believed to be the major source of the world’s fresh air
Tropical Rainforest - Climate
• Hot all year…very little variation in temperature
• No true seasons• Humidity is always high• Rains almost every day,
usually in the afternoon.• Annual precipitation – 80-
160”
Rainforest Structure
Rainforest Structure– Similar structure as
temperate forests plus the emergent layer
– Canopy is very thick. • Only 1% of sunlight
ever reaches the forest floor.
Rainforest Animals
• Highest biodiversity in the world
• Contains at least ½ of the entire world’s plant and animal species
• Species are highly stratified. There is very little competition between species.
• Most animals live in the canopy because of the presence of sunlight.
Rainforest Animals
Rainforest Vegetation
• Trees are very tall (180’) with broad, evergreen leaves.– Mahogany
• Leaf cover is very dense, restricting growth of competing plants
• Roots are shallow to increase absorption of soil nutrients
Vegetation Adaptations
• Shallow tree roots are supported by buttresses.
• Understory plants have huge leaves to maximize sunlight for photosynthesis (elephant ear)
Specialized Rainforest Plants
• Epiphytes– Plants that grow on tree
branches and trunks.
– Roots absorb moisture directly from the air
– Debris collects around their roots forming pockets of organic matter which they use as a nutrient source.
Specialized Rainforest Plants
• Lianas– Climbing vines
– Roots are in the shallow soil, but the main plant is found in the canopy
– Uses the trunks and branches of trees for support to reach the sunlight
Human Impacts on Forests
• Man is clearing the forests faster than the trees can regrow.
• Temperate forests are cleared in N. America, Europe and Asia for timber, cropland and urban development.
• Conifer forests in N. America, Canada and Russia are cleared for timber, mining and hydroelectric dams.
• Tropical rainforests are cleared for timber, domestic cattle and agriculture.