Savanna (Tropical grassland) Zeina Fahim Science 6A Male_li on_on_savanna.jpg.
Tropical Grassland -Savanna-
description
Transcript of Tropical Grassland -Savanna-
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Tropical Grassland-Savanna-
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ClimateTemperature20o-30o CelsiusAverage Rainfall100-400 mm per year (80% in wet season)SunlightLots of sun during dry seasonGrasses are mostly C4
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Soil FertilitySoil FertilitySandy, dusty, high iron content (reddish color) Not very richTermites turn the soil to air itDead plant matter cant decompose in dry season
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Seasonal ChangesWet4-5 monthsEquatorial low pressure beltHeavy convectional storms80% total annual rainfallDryStrong, steady trade windsDry and warm as they blow towards equator
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CharacteristicsVegetation100-200 mm rainfall-only grasses300 mm rainfall-shrubs< 300 mm rainfall-solitary trees< 400 mm rainfall- trees, canopy, shade Trees-deciduous-lose leaves in winterShrubs/Grasses-C4
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GeographyLocation5o-15o north and south of equatorLlanos (Venezuela), Campos (Brazil), Central Africa, Australia, Mexico
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Limiting FactorsRainFireSoil Fertility
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Animal Life and AdaptationsForm herds and colonies for protectionCare for young Lookout for predators
Meekrat- Suricata suricatta siricata Nigriceps Ant- Crematogaster nigriceps
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Animal Life and AdaptationsGrazing herbivores adopt migratory lifestylesLong legs, wings
African Elephant- Loxodonta africanaGrants Zebra- Equus burchelli bohmi
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Animal Life and AdaptationsAnimals give birth only during rainy seasonFood is abundant More offspring than predators
Dama Gazelle- Gazella dama
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Animal Life and Adaptations
Herbivores reduce competition for foodFeed at different heights Giraffe- Giraffa camelopardalisDarma dik-dik- Madoqua kirkii
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Animal Life and Adaptations
Small animals burrow deep undergroundWaterDormant during dry season African Ground Squirrel- Xerus inauris
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Plant Life and AdaptationsFireThick, fire resistant barkBuds in bark sprout after firesSeeds that germinate in ashes Bottle trees- Adansonia digitata
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Plant Life and AdaptationsFireLignotubers
Eucalyptus trees- Eucalyptus globulus
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Plant Life and AdaptationsWaterdrought deciduous River Bushwillow- Combretum erythrophyllum
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Plant Life and AdaptationsWaterLong roots extending far underground (Taproot system)Corkscrew-shaped awns
Red Oat Grass- Themeda triandra
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Plant Life and AdaptationsDefenseThorns and leathery,sharp leaves for protectionToxic chemicals
Elephant Grass- Pennistum purpureum Whistling Thorn tree- Acacia dreparalobium
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Plant Life and AdaptationsSenegal Gum Acacia- Acacia senegal
Jackal Berry Tree- Diospyros mespiliformis
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Changes in Last CenturySavanna has shrunkSome has been replanted by humansIntroduction of exotic plants
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Human ActivitiesNomadic cattle grazingSoil erosion by overgrazingMan-made fireUsed to control grasses and for huntingTree clearingClimate changeIntroduction of exotic plants
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ConservationReplanting destroyed grassesMonitoring endangered plants and animalsPreserves and National Parks
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The Circle of LifeWet SeasonDry SeasonAnimal adaptations