The Biome
Location
Although the tropical rainforest biome covers only 6% of the earth's surface, the tropical rainforest is a very important biome on our planet when it comes to things like plants and animals. The rainforest may not be number one on your list of places to live, but "more than half the world's plant and animal species live in the tropical rainforest." The tropical rainforest biome also produces 40% of the Earth's oxygen! Most of the tropical rainforests are "located in a band 4800 km wide around the equator, mostly in the area between the Tropic of Cancer and the Tropic of Capricorn." The three main tropical rainforests are in Central America in the Amazon River Basin; Africa in the Zaire Basin, with a small area in West Africa as well as eastern Madagascar, and indo-Malaysia on the west coast of India, Assam, Southeast Asia, New Guinea, and Queensland Australia.
Climate
The climate of the tropical rainforest is always hot and humid. "The temperature rarely gets higher than 34 degrees celcius or drops below 20 degrees celcius" because of the biome's proximity to the equator, and there is an average of 50 to 260 inches of rainfall yearly. There are only 12 hours of sunlight in the rainforest, and less than 25 of that sunlight reaches the forest floor because of the four layers of trees that tower above it.
Layers and Trees of the Tropical
Rainforest Biome
The first thing you think of when you hear the word "rainforest" are the trees. This is because it is the dominant life form in the biome and makes up 70% of the plants in the rainforest. The tropical rainforest has more kinds of trees than any other area of the world. There are several interesting characteristics in trees that grow in rainforests. Similar to the trees in forests in Vancouver, "Many trees have straight trunks that don't branch out for 100 feet or more." The trees have thin bark in the rainforest because there is no need for protection against cold or freezing temperature and water loss. Scientists find it difficult to identify trees by their bark in the rainforest, because the bark is very similar on each tree, instead it is easier to identify the trees by their flowers.
Although the tropical rainforest biome covers only 6% of the earth's surface, the tropical rainforest is a very important biome on our planet when it comes to things like plants and animals. The rainforest may not be number one on your list of places to live, but "more than half the world's plant and animal species live in the tropical rainforest." The tropical rainforest biome also produces 40% of the Earth's oxygen! Most of the tropical rainforests are "located in a band 4800 km wide around the equator, mostly in the area between the Tropic of Cancer and the Tropic of Capricorn." The three main tropical rainforests are in Central America in the Amazon River Basin; Africa in the Zaire Basin, with a small area in West Africa as well as eastern Madagascar, and indo-Malaysia on the west coast of India, Assam, Southeast Asia, New Guinea, and Queensland Australia.
Climate
The climate of the tropical rainforest is always hot and humid. "The temperature rarely gets higher than 34 degrees celcius or drops below 20 degrees celcius" because of the biome's proximity to the equator, and there is an average of 50 to 260 inches of rainfall yearly. There are only 12 hours of sunlight in the rainforest, and less than 25 of that sunlight reaches the forest floor because of the four layers of trees that tower above it.
Layers and Trees of the Tropical
Rainforest Biome
The first thing you think of when you hear the word "rainforest" are the trees. This is because it is the dominant life form in the biome and makes up 70% of the plants in the rainforest. The tropical rainforest has more kinds of trees than any other area of the world. There are several interesting characteristics in trees that grow in rainforests. Similar to the trees in forests in Vancouver, "Many trees have straight trunks that don't branch out for 100 feet or more." The trees have thin bark in the rainforest because there is no need for protection against cold or freezing temperature and water loss. Scientists find it difficult to identify trees by their bark in the rainforest, because the bark is very similar on each tree, instead it is easier to identify the trees by their flowers.
There are four layers of trees in the tropical rainforest: emergant (the top layer), canopy (the second layer), understory (the third layer), and the forest floor. The emergent layer rise above all the other layers of the forest. The trees in this layer can grow up to a height of 200 feet, with trunks 16 feet around. "Most of these trees are broad-leaved, hardwood evergreens." The animals found in this layer include eagles, bats, monkeys, and butterflies. The trees in this layer get the most sunlight, and survive high temperatures and strong winds.
The canopy's trees are usually 60 to 90 feet tall above ground, and their branches are "often covered with other plants and tied together with vines. The leaves on these trees are usually smooth and oval shaped. The canopy is home to 90% of the organisms found in the rainforest." This is because of the abundance of food sources this layer has to offer. Some of the animals that live in this layer include snakes, toucans, and treefrogs.
"The understory is relatively open and contains young trees and leafy herbaceous plants that tolerate low light." The trees in this layer have to grow larger leaves to reach the sunlight. Little of the plants in this layer grow higher than 12 feet tall. There are many animals that live in this layer, including jaguars, red eyed tree frogs, and leopards. There are many insects that live in this layer as well.
The forest floor is surprisingly infertile and acidic because the heavy rain washes away the majority of minerals in the soil. The nutrients are also "quickly recycled and not retained." The limited amount of sunlight that reaches the floor is also a factor in why there is so little plant life on the floor. Plants on the forest floor are most likely to be found near riverbanks because they break up the canopy so that plants can get sunlight, and on hillsides because the angle of growing surface also allows sunlight to reach the plants. Giant anteaters are one of the interesting animals that live in this layer of the forest.
The canopy's trees are usually 60 to 90 feet tall above ground, and their branches are "often covered with other plants and tied together with vines. The leaves on these trees are usually smooth and oval shaped. The canopy is home to 90% of the organisms found in the rainforest." This is because of the abundance of food sources this layer has to offer. Some of the animals that live in this layer include snakes, toucans, and treefrogs.
"The understory is relatively open and contains young trees and leafy herbaceous plants that tolerate low light." The trees in this layer have to grow larger leaves to reach the sunlight. Little of the plants in this layer grow higher than 12 feet tall. There are many animals that live in this layer, including jaguars, red eyed tree frogs, and leopards. There are many insects that live in this layer as well.
The forest floor is surprisingly infertile and acidic because the heavy rain washes away the majority of minerals in the soil. The nutrients are also "quickly recycled and not retained." The limited amount of sunlight that reaches the floor is also a factor in why there is so little plant life on the floor. Plants on the forest floor are most likely to be found near riverbanks because they break up the canopy so that plants can get sunlight, and on hillsides because the angle of growing surface also allows sunlight to reach the plants. Giant anteaters are one of the interesting animals that live in this layer of the forest.