AIM: SWBAT describe the unique
features of the tropical
grassland/savanna biome
Please Do Now: What, in terms of
climate, separates the temperate
grassland from the temperate forests?
Agenda
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•
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Do Now
Begin Savanna Notes
Savanna Video
Return Exams
Tropical Grassland/Savanna
• Found near the equators in place to dry to
support a forest. Largest examples are found on
Africa and South America
Out of order *Unique sub-habitats* out of order
• The tropical grassland consist of just grass,
while the savanna has widely spaced trees
also. Their animal communities are very
similar and that is why they are grouped
together. They are found right next to each
other in many locations.
Climate
• Precipitation is variable
with a wet season and a
dry season
• Temperature are hot
throughout the year
Soil
• Like the temperate
grasslands, the soils
tend to be very rich,
with lots of organic
content, which is
replenished by the
frequent wildfires.
Plant Life
• characterized by the
trees being sufficiently
widely spaced so that
the canopy does not
close. The open canopy
allows sufficient light to
reach the ground to
support an unbroken
herbaceous layer
consisting primarily of
grasses
Plant’s Adaptations
• Trees have thick bark,
thorns, loose leaves in
dry season
• Grasses grow in clumps,
shoots (aboveground
tissue) dies during dry
season
Seasonal Variation
• In terms of
temperature, very little
• In terms of
precipitation, very high.
There is a marked dry
season and wet season,
which drive the
migrations here, the
largest on earth
Limiting Factors and Adaptations
• On your own
Diversity and Productivity
• Above average diversity,
thanks to the many
micro-habitats, and
high productivity
• Productivity: 8
DO NOW
• What is likely the limiting factor for herbivores
in the savannah? (Write on the packet in 3
minutes or no credit).
Agenda
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•
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•
Do Now
Anteaters
Savannah
Video
Succession
• The savannah biome is constantly changing,
wildfires restart succession all the time, with
tough grasses regrowing quickly after, and some
trees with fires resistant bark surviving largely
intact
• When the climate changes (for the drier or
wetter) trees die off or grow more dense
• Animals themselves also influence succession.
The savannah would probably have many more
trees than it does if it were for the damage large
herbivores like elephants do to young trees
Keystone species
• The elephants use their
huge size to take down
trees, which keeps the
savannah open canopied
for grasses to grow
• Termites are very
common on the
savannah, and convert
the energy in grasses and
wood to more edible
forms
Migrations
• Extremely common
because of the dry
season.
• Grazers move to find
areas with better grass
to rear their young
• Predators follow or
attack them along the
route
Mating Systems
• Lek mating and
polygyny is common in
the grazers of the
tropical grasslands and
savannah
• Lions and some other
big cats are famous for
their polygynous mating
habits (alpha males)
Example organisms / Trophic Pyramid
• During the video
Symbioses
• Many birds live off the
bugs that parasitize
large herbivores
– Example: oxpecker
– Also, acacia trees have a
protective symbioses
with stinging ants
Threats to Conservation
• Conversion to farmland
or cattle pasture
• Poaching of the
important large
herbivores
AIM: The savanna continued
Please Do Now: Think about it (hard question)
write minimum 2-3 sentences.
Why might the structure of the savanna
(grasslands with trees) be more likely to have
high biodiversity than a plain tropical
grassland?
Agenda
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•
•
•
Do Now
Few Savannah Slides
Explain tomorrow
Correct Midterms
Famous Examples
• The Cerrado of Brazil
• The Serengeti of East
Africa
Vocabulary
• Perennial: In reference to plants, a life-strategy
where individual plants live more than one year
(usually above ground parts die and are regrown
from the roots) (opposite of perennial = annual)
– The grasses in the savannah are almost all perennials
Tomorrow
• Tomorrow we will be in the computer lab,
where you will use the internet to fill in a
packet on your own (so exciting YAY)
• It will count as half your quiz grade for the
week
• The biome will be: Mediterranean forests
Correcting your exams
• On loose leaf WITH justifications for those you
got incorrect