B6: Tropical Rain Forests Flashcards
Section B: Chapter 6 [2nd Edition Textbook]
Where are tropical rainforests located?
Mostly around the equator, and between the tropics of cancer and the tropics of Capricorn
Why are tropical rainforests located near the equator?
Because of the direct sunlight on the equator - the temp is higher, so where there is moisture, the hot air will rise and form clouds - causing rain - and so a tropical rainforest
What is the soil like in a tropical rainforest?
They are mainly thin and poor, because of leaching from the rain water.
The warm and humid conditions cause the litter to decompose very quickly and the rain washes away any nutrients before they become a part of the soil.
How is there so much vegetation despite the lack of nutrients in the soil - in a tropical rainforest?
Because of the rapid nutrient cycling - most of the nutrients are stored in the biomass and the litter.
The warm and humid conditions cause the litter to decompose very quickly and the rain washes away any nutrients before they become a part of the soil. But the plants still pick up enough nutrients from this to survive.
What is the climate like in a tropical rainforest?
The climate is consistent at around 27 degrees all year, with no major seasonal changes.
Rain is high between January to may - it peaks in march with 295mm, and dips in august with only 56mm, rising again in December to 222mm.
Describe the layers of the rainforest from lowest to highest.
Soils - high in iron low in nutrients
Shrub layer - less than 5m, little light so few shrubs
Under canopy - 5-15m, trees of different ages and sizes
Canopy- 15-30m, trees of different ages and sizes
Emergent- 30-60, tallest trees that grow to maximize amount of received sunlight.
How are buttress roots adapted?
These “above-ground” roots help support and anchor the tree, much as a buttress on a fort would support the walls of the fort. Leaf litter collects between these buttress roots so the tree has access to more nutrients when the collected leaves decompose. Buttress roots also absorb oxygen directly from the air
How are lianas adapted?
The liana vines use a number of different adaptations to attach themselves to trees. These include twining or wrapping themselves around a tree, thorns or spikes which provide a solid support and a kind of adhesive which literally helps the vine stick to a tree.
How are Drip tip leaves adapted?
Drip tips - plants have leaves with pointy tips. This allows water to run off the leaves quickly without damaging or breaking the leaves.
How is Rafflesia adapted?
The rafflesia produces the stench of rotting flesh to attract carrion flies for the pollination process. The fly collects the pollen from the male flower to a female flower to continue the pollination process. The foul stench it produces is an example of its unique adaptations to reproduce.
How are spider monkeys adapted?
They possess long tails that help them grab branches and swing through canopies, and the young are able to cling to their mothers backs several months after birth so that their mothers can maintain an arboreal lifestyle.
How are jaguars adapted?
Jaguars have jaws and a large head especially equipped for piecing the skull of their prey with their canines. They are the only big cats which practice this habit. Unlike other large cats, who attack at the neck, jaguars often kill their prey with a single bite to the back of the head.
How are potoos adapted?
The upper eyelids of Potoos have several small folds which create slits that serve as “peek-holes” during the day. This adaptation allows the potoo to keep an eye on potential threats while remaining still and keeping its enormous eyes closed.
How are three toed sloths adapted?
Sloths have specialized tendons in their hands and feet that lock into place, allowing them to hang upside down for long periods of time without wasting any energy. Sloths are so slow moving that green algae grow on their shaggy fur, which helps camouflage them in the trees.
How does logging lead to deforestation in the Amazon Rainforest?
Accounts for 3% of deforestation
Due to Mahogany (expensive, sold for £1000 per m^3)
Other woods to make furniture, timber or fuel.
Access routes are also cut to get through the forest.
For every tree felled - 28 others are damaged.
estimated that 50% of this is illegal
How does Mining lead to deforestation in the Amazon Rainforest?
There are useful materials - like lead, tin, gold, copper, and aluminum that are mined.
After, the land is left permanently damaged, as many meter of rock are removed, and soil is destroyed.
People employed are doing cheap, but hard labor - in poor conditions and for little pay.
How does Cattle ranching lead to deforestation in the Amazon Rainforest?
This causes 80% of all deforestation
Xebu cows are exported to other countries like China and some in the EU.
The land the cattle graze can’t be used for long, so more land has to be cleared out- the previous land is left unfertile due to overgrazing, and deforestation causes soil erosion + leeching as no roots hold the soil together.
Soya has to be grown to feed the cows, so more land is cleared.
How does road building lead to deforestation in the Amazon Rainforest?
The Trans-Amazonian Highway is planned to be 4000km long.
This will destroy 275,000 hectares of land, including a national park, and 2 indigenous reserves.
This highway will also encourage other activities like agriculture as there is now more access.
How will road building be beneficial?
50% of the population is considered poor and 30% of these people are below the national poverty line - these people have a right to a better life through the Trans-Amazonian Highway so they can access more jobs
If Peru develops the highway, they could get better trade which means that they don’t need to use large areas of land in the rainforest as income. This could be beneficial to the Amazon in the long term.
What are the global impacts of deforestation?
Global warming - loss of a CO2 store; wood released CO2 when burned, and less trees means less photosynthesis so less CO2 being consumed.
This leads to the enhanced greenhouse
effect, which traps heat in the
atmosphere.
Loss of biodiversity: Individual species could be endangers or extinct, and the overall biodiversity could be reduced. Loss of particular cures and medicines that were yet to be discovered through species in the rainforests.
What are the local impacts of deforestation in the Amazon?
Soil erosion and fertility - once trees are removed, the topsoil is washed away by rain, and nutrients are easily leeched or washed away as the tree roots don’t hold the soil together. This leads to soil erosion and leaves the land unfertile
River pollution - gold mining uses mercury to separate the hold from the ground. but sometimes, the mercury ends up in water, which poisons fish and pollutes nearby towns.
Leads to the decline of indigenous people, displacing them to towns and cities. Many people struggle to adapt to this lifestyle, so drug and alcohol addiction is common.
How are rainforests important in medicine?
