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.
Why is subsistence farming a cause of deforestation?
One of the methods used in subsistence farming is called slash and burn. It makes the soil unfertile, as much of it washes away in the rain, it can be sustainable, provided that the trees are given long enough to grow back, but it often isn’t. Slash and burn makes up 70% of all deforestation, and makes up 17% of the world’s greenhouse gases. This technique is used by 300 million people worldwide, and it was estimated 500,000 small farmers were clearing a hectare a year through this method.
Why is logging a cause of deforestation?
Malaysia is described as “mega diverse” by Conservation International and its rainforests host around 20% of the world’s species. However, Malaysia had the highest rate of forest loss in the world between 2000 and 2012. 30% of the Congo has been allocated for logging, and 90% of Malaysia’s lowland forests have been allocated as well. Only $8 million is being earned by the Malaysian government from logging, 12 cents per person.
Can logging be a good thing?
It can be, because the World Bank suggests that the logging industry could create 300,000 new jobs in Malaysia. If 1 - 2 million cubic metres of timber were sold, Malaysia could generate $200 - 400 million from this.
Why is mineral extraction a cause of deforestation?
Yasuni National Park in Ecuador has over 20 endangered mammals in it. The Ecuadorian government said it wouldn’t drill for oil there, as long as they got $3.6 billion, but they only received $13 million. In Malaysia, annual output of bauxite ore has increased to 20 million tonnes. It is strip mined, however Malaysia only has 10 years worth of the reserves left. The noise affects residents and a broken pipeline spilled 400,000 gallons of oil into the Coca River. This left 65,000 people without water.
Can mineral extraction be a good thing?
Malaysia is now the world’s top producer of bauxite, and it accounts for half of the supplies to the Chinese aluminium industry. The project in the Yasuni National Park in Ecuador will help to stop poverty, and will generate around $7 billion for the country. By 2019, Ecuador hopes to extract a quarter of a million barrels per day.
Why is energy development a cause of deforestation?
The Bakun Dam in Sarawak, at 205m, is Asia’s highest dam outside China. The dam’s reservoir flooded over 700 square kilometres of forest and farmland. They account for 5% of total deforestation. However, people have to be displaced and wildlife can be killed. The dams can get clogged with silt, which makes them useless, and they can reduce flow downstream which affects farmers. The standing water in the reservoirs can also cause malaria.
