Tropical Rainforests Flashcards
Where are tropical rainforests found?
Deserts are located in the Tropics, the Tropic of Cancer and the Tropic of Capricorn, 30° north and south of the Equator. They are located on every continent except from Antarctica. The largest desert is the Sahara, and it covers 11 countries, including Egypt, Morocco, Niger, Mali, Chad, Sudan, Eritrea and Mauritania.
What is the soil profile like in the tropical rainforest?
The O Horizon (humus layer, usually formed of decomposing animals, litter and leaves) is very thin. This is because the material decomposes very fast in the tropical climate. The A Horizon (buildup of humus which has decayed) is very large, as the leaf litter is abundant, and it breaks down easily. There is no B Horizon (sturdy soil, made up of clay) in the tropical rainforest, and this makes it loose and vulnerable to washing away. The C Horizon (rock) and the bedrock are thin layers also.
What do the different layers of soil do in a tropical rainforest?
The A Horizon is made up of decayed material low in minerals and nutrients, and does not support plant life. The O Horizon is washed away easily by rainstorms that occur almost every day. The rainforest depends on the soil for its nutrients, and this is called the nutrient cycle.
What are some examples of interdependence in the rainforest?
The Brazil Nut Tree depends on the agouti to scatter its seeds, and the tree gives the agouti shade and shelter, as well as a place to live.
What is the forest floor of a rainforest like?
The forest floor gets around 2% of light. The height of this layer is from 0 - 5m, and many insects live here, as well as jaguars, gorillas, humans, pumas and snakes. There is no grass here, and it is the most humid part of the rainforest. The underlying soil is hidden by a thin layer of rotting leaves. Fungi and termites decompose this layer.
What is the shrub layer of a rainforest like?
The shrub layer goes from 5 - 20m above the ground and it is the layer with the densest plant growth, where there are shrubs, saplings and ferns. It receives about 25% of light.
What is the understorey layer of a rainforest like?
The understorey goes from 15 - 20m above the ground. It is dark, meaning that there aren’t many plants, however ferns, mosses, vines, insects and birds live here. It gets around 50% of light.
What is the canopy layer of a rainforest like?
The canopy goes from 20 - 30m above the ground, around receives around 75% of light. There are birds, insects, arachnids, reptiles, mammals, possums and vines all living here.
What is the emergent layer of the rainforest like?
This layer is full of very tall trees, stretching 35 - 40m into the air. The conditions are very windy, and hot, however macaws, monkeys and insects live here. This layer gets 100% of light.
How has the spider monkey adapted to living in the rainforest?
The spider monkey can grow up to 2 feet, and they have a powerful tail which they use as an extra limb. They hang upside down from tree branches, which makes them look like a spider. They can swing from branch to branch at high speeds, and spend most time in the canopy.
How has the toucan adapted to living in the rainforest?
Toucans have large and colourful bills, which helps them to attract mates. It is also very lightweight, and their calls are harsh and raspy. The toucan’s bill is sharp and has saw like edges, which they use to tear fruits off trees. They eat smaller birds, reptiles and lizards.
How has the fan plant adapted to living in the rainforest?
Fan palms have large, fan shaped leaves that are good at catching sunshine and water. Their leaves are segmented, meaning excess water can drain away. The fan shape also provides shade.
How has the liana adapted to living in the rainforest?
Lianas are woody vines that start at ground level, and use the trees to climb up to the canopy, where they spread from tree to tree, to get as much light as possible. They bury their roots deep within the ground, meaning they have a stable base. Many lianas grow to 200m, and supports weaker trees in heavy wind and rain.
What is deforestation?
Deforestation is the process in which natural forest is cleared through burning and cutting the trees for both commercial and private uses. 36 football fields a minute of rainforest are cut down.
What are the impacts of deforestation?
Reduced biodiversity, as animals lose their habitat, and 50% of the world’s plant and animal species are found in the rainforest. Greenhouse gases are also produced, and deforestation accounts for 15% of the global greenhouse gases that are produced. Trees can no longer absorb water from the soil, meaning the water cycle is disrupted. This can make the climate drier. Increased soil erosion also takes place, as the trees no longer hold the soil in place.
What are the causes of soil erosion?
Compaction is where the soil becomes squashed because there is no vegetation to protect it. The loss of soil structure means that the layers in the soil profile are disrupted, and the nutrient cycle becomes ineffective. As trees are cut down, there is no longer any leaf litter to provide nutrients. When the water evaporates, lots of salt is left behind, killing crops and plants.
Why is palm oil a cause of deforestation?
Palm trees produce red fruits which have a very high yield of oil. Palm oil is used for makeup, chocolate and biodiesel. A single hectare can produce 7 tonnes of oil. It is a good alternative to fossil fuels. However, the increase in palm oil production is linked to the decrease in rainforest cover. For example, in Indonesia, in 1964, there was no palm oil produced, but 120 million hectares of forest, and in 2006 there was 16.1 million tonnes of palm oil produced, and 80 million hectares of forest.
Why is road building a cause of deforestation?
Roads have to be constructed to provide access to mining areas. In the Amazon Rainforest, 30,000 miles of rainforest was cut down for roads. Around 10,000 miles of roads were built in Brazil each year from 2004 to 2007. The Trans - Amazonian Highway in Brazil is 5,300 km long and has destroyed many habitats.
