Ecosystems
of the
World
Climax Vegetation - the natural vegetation in the last possible
stage of vegetation development.
• Climax vegetation is in balance with the climatic conditions.
• It should change very little if left undisturbed.
Climax vegetation in boreal (coniferous) forest:
* Evergreen trees
* Needle like leaves
* Thick bark
* Conical shape
* Drooping branches
Climate is temperate cold
winter – these trees are
hardy enough to endure
long winters with limited
water.
* needle leaves reduce surface area meaning less water loss.
* thick bark reduces water loss.
* drooping branches and conical shape allow heavy snow to fall off
relieving the pressure.
Complete # 19 on pages 102 – 103.
a. Boreal Forest & Tundra
are wide spread in high
latitudes.
b. Tropical Rain Forests
occur in low latitudes.
c. Tropical Rain Forest is
most predominant in
South America.
d. South America, Africa,
Australia and Antarctica
do not have tundra.
e. Boreal Forest is our
ecosystem.
Elevation and Latitude Affect Ecosystems
• The changes in ecosystems from the equator to the poles is very
similar to the changes in ecosystems from the base of a tropical
mountain to the summit.
Complete # 23 on page 105.
A = Temperate Deciduous Forest
B = Tropical Rain Forest
C = Grasslands
D = Savanna
E = Tundra
F = Coniferous Forest
G = Desert
Complete # 24 on pages 105 – 106.
Ecosystem A = Savanna
Ecosystem B = Boreal Forest
Ecosystem C = Temperate Forest
Ecosystem D = Temperate Grassland
Ecosystem E = Tropical Rainforest
Ecosystem F = Tundra
Ecosystem G = Desert
Complete # 25 on page 107.
Tropical Rain Forest
Answer
Answer
Answer
Ecosystems and Climatic Regions
Ecosystems of the world are largely defined by their climax vegetation.
Example: tropical rain forest, grasslands, boreal forests, cacti, etc.
Climax vegetation is determined by climate.
Therefore, ecosystems parallel climate zones.
Ecosystems and Climatic Regions
Temperate cold winter gives Boreal Forest
Temp. mild winter gives Temp. deciduous Forest
Semi-Arid gives Grassland
Arid gives Desert
Tropical Wet gives Tropical Rain Forest
ECOSYSTEM
Tundra
Boreal
Forest
Temperate
Forest
Temperate
Grassland
CLIMATIC CONDITIONS
Polar to subarctic climate
- short summers
- temperature always below 100 C
- very cold long winters
- light precipitation
Temperate cold winter climate
- warm summers
- moderate precipitation
Temperate mild winter climate
- mild winters
- quite warm to hot summers
- moderate to heavy precipitation
Steppe to semi-arid climate OR
Temperate cold winter (in some
cases)
- light precipitation usually in
summer
- warm to hot summer temperatures
- cold winters
CLIMAX VEGETATION
Grasses and shrubs with
shallow roots that
reproduce quickly
Evergreen trees with
needle leaves & thick bark
that reduce moisture loss
Deciduous trees like oak &
birch that lose their leaves
in fall to reduce moisture
loss
Grass with shallow roots
that require little water
ECOSYSTEM
CLIMATIC CONDITIONS
CLIMAX VEGETATION
Savanna
Tropical wet/dry to semi-arid climate Grass with shallow roots
- high temperatures most of year
that require little water
- light to moderate precipitation
usually during one season
Desert
Arid climate
- high temperatures all year
- very light precipitation
Plants that are thick, have
needles, long roots, and can
store water.
Tropical
Rain Forest
Tropical wet climate
- high temperatures all year
- heavy precipitation most of year
Tall evergreen broadleaf
trees that have broad roots
in thin soil to support
height
Mountain
Varied climate but usually cold due
to high elevations
- Conditions depend on where
mountains are
- Quite similar to tundra ecosystem
at highest elevations
Vegetation varies with
elevation and temperature