Tropical Savannas and Woodlands

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Tropical Savannas and Woodlands
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Tropical savannas are grasslands with a
scattering of shrubs or trees. Tropical woodlands
have a higher density of trees, but they do not
form a continuous canopy.
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Tropical savanna and woodlands cover about 20 of
the earths land area, with the largest
concentration being found in Africa.
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Savanna locations are heavily influenced by the
Intertropical Convergence Zone.
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Seasonality of rainfall helps control savanna
distribution.
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Native human populations live largely by
pastoralism.
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The Serengeti-Mara ecosystem contains the worlds
greatest concentration of large mammals.
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The Serengeti illustrates many of the
relationships that are important in ecosystems.
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More than 3 million ungulates of 28 species
inhabit the region.
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These herbivores consume about 66 of the
aboveground net primary production. Probably the
largest fraction of any ecosystem.
Areas subjected to grazing show primary
production about twice that of protected
areas. Grazing lawns.
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Migrations follow a gradient of forage abundance
and nutritional quality. Wildebeest, plains
zebras, and Thomsons gazelles spend the wet part
of the year on the southern plains. As forage
begins to dry and disappear, they move northwest,
then gradually concentrate in the northern area
near the Kenyan border. When rains resume, they
return south to the plains.
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Grazing by the migratory species is
complementary. Zebras first, followed by
wildebeest, and then Thomsons gazelles.
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Many carnivores feed on the herbivores
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Fragmentation of the savanna habitat is a major
threat to the wildlife of the region.
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Perhaps the largest threat is poaching.
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African black rhino
Javan rhino
Indian rhino
Sumatran rhino
African white rhino
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Distribution of the Javan rhino