Umbrella thorn tree
The Umbrella Thorn is a member of the Acacia tree family and grows thought out Southern Africa. It is a fairly slow growing tree and reaches a final height of between 5 to 20 meters with a spread of 8 to 13 meters. The height of a fully grown tree prevents overgrazing by herbivores.
It grows in the tough African conditions with an annual rainfall as low as 4cm and survives in 50°C day time temperatures and freezing night temperatures that can drop below -18°C.
Animals feed on the leaves as well as the unopened seed pods that fall to the ground. The unopened seed pods ensure better germination after passing through an animal's stomach.
The thorns on the tree are thin and grow in pairs in a combination of one straight thorn with a small hooked thorn.
The Umbrella Thorn gets its nutrients through photosynthesis (leaves) and water and minerals in the ground (tap root system).
It grows in the tough African conditions with an annual rainfall as low as 4cm and survives in 50°C day time temperatures and freezing night temperatures that can drop below -18°C.
Animals feed on the leaves as well as the unopened seed pods that fall to the ground. The unopened seed pods ensure better germination after passing through an animal's stomach.
The thorns on the tree are thin and grow in pairs in a combination of one straight thorn with a small hooked thorn.
The Umbrella Thorn gets its nutrients through photosynthesis (leaves) and water and minerals in the ground (tap root system).
Umbrella thorn tree's adaptions
Like other Acacia trees, the Umbrella Thorn releases a chemical into the soil which prevents its own saplings from growing and therefore reduces the competition for water.
The tree can survive drought conditions because it has developed long tap roots that can reach deep into ground water sources.
It is also fire resistant, with some varieties re-sprouting from the root crown when the above ground portion of the tree is damaged by fire.
It has developed long, sharp thorns and a symbiotic relationship with stinging ants. The ants live in hollowed out Acacia thorns and feed on the nectar produced by the tree. When animals take a bite of the leaves (and thorns), they also get a mouthful of angry, stinging ants. The ants also defend their homes from other insects, thereby protecting the Acacia Tree.
Giraffes graze on the tops of the acacia, which results in the dome-shaped top. To preventing giraffe grazing, the tree has developed a chemical defence system that is triggered when the giraffe begins feed. First, a nasty tasting poisonous alkaloid is pumped into the leaves. The giraffe only gets a couple of mouthfuls of leaves before the remaining leaves become inedible. Then, the tree warns other acacia trees in the area by emitting a chemical into the air. The other acacia trees respond by pumping alkaloid into their leaves.
These adaptations help the thorn tree to survive in this ecosystem.
The tree can survive drought conditions because it has developed long tap roots that can reach deep into ground water sources.
It is also fire resistant, with some varieties re-sprouting from the root crown when the above ground portion of the tree is damaged by fire.
It has developed long, sharp thorns and a symbiotic relationship with stinging ants. The ants live in hollowed out Acacia thorns and feed on the nectar produced by the tree. When animals take a bite of the leaves (and thorns), they also get a mouthful of angry, stinging ants. The ants also defend their homes from other insects, thereby protecting the Acacia Tree.
Giraffes graze on the tops of the acacia, which results in the dome-shaped top. To preventing giraffe grazing, the tree has developed a chemical defence system that is triggered when the giraffe begins feed. First, a nasty tasting poisonous alkaloid is pumped into the leaves. The giraffe only gets a couple of mouthfuls of leaves before the remaining leaves become inedible. Then, the tree warns other acacia trees in the area by emitting a chemical into the air. The other acacia trees respond by pumping alkaloid into their leaves.
These adaptations help the thorn tree to survive in this ecosystem.
African Grass
Grasses are the dominant plant life in the Savanna. A wide variety of grasses grow in different regions in the Savanna, serving as the main food source for most herbivores.
Some grasses grow 3 meters tall, such as Elephant Grass.
Savanna grasses are often in thick clumps with bare ground and shrubs in between. The African Savanna has distinct wet and dry seasons, with grasses only growing in the wet season.
Grasses on the Savanna have narrow leaves to limit the amount of water lost in the hot and dry conditions.
The grasses get their nutrients through their leaves (photosynthesis) and their root systems (water and minerals).
Some grasses grow 3 meters tall, such as Elephant Grass.
Savanna grasses are often in thick clumps with bare ground and shrubs in between. The African Savanna has distinct wet and dry seasons, with grasses only growing in the wet season.
Grasses on the Savanna have narrow leaves to limit the amount of water lost in the hot and dry conditions.
The grasses get their nutrients through their leaves (photosynthesis) and their root systems (water and minerals).
African Grass Adaptations
For the grasses to survive the dry season, they grow quickly in the wet season when there is a lot of water. When water becomes scarce, the grasses turn brown to limit water loss. Moisture and nutrients are stored below the ground in their roots while they wait for the wet season to return.
With food and water reserves stored below ground, the grasses are also able to survive fires. In fact, the fires stimulate new growth and restock the soil with nutrients.
The grasses have adaptations that discourage animals from eating them. For example, some grasses are too sharp or bitter tasting for some animals but not others.
Some animals will eat different parts of the grass. Many grasses grow from the bottom up, so that the growth tissue doesn't get damaged.
These adaptations help the grasses to survive in the African Savanna.
With food and water reserves stored below ground, the grasses are also able to survive fires. In fact, the fires stimulate new growth and restock the soil with nutrients.
The grasses have adaptations that discourage animals from eating them. For example, some grasses are too sharp or bitter tasting for some animals but not others.
Some animals will eat different parts of the grass. Many grasses grow from the bottom up, so that the growth tissue doesn't get damaged.
These adaptations help the grasses to survive in the African Savanna.