tropical rainforest (amazon rainforest) Flashcards
define the soil in tropical rainforests
the heavy rainfall in the tropical rainforest leaches the soil as nutrients are washed away. however, there are surface nutrients due to decayed leaf fall, but this layer is very thin as decay is fast in the warm moist conditions of the tropical rainforest
describe nutrient cycling in the rainforest
when dead material decomposes nutrients are released into the soil. the nutrients are then taken up from the soil by plants. the plants may be eaten by consumers. when the plants or consumers die, the nutrients are returned to the soil. this transfer of nutrients is called nutrient cycling
the climate in tropical rainforests
the climate is the same all year round- there are no definite seasons. it’s hot. This is because the suns energy is more intense near the equator as it is overhead all year-round
rainfall is very high, around 2000 mm per year. it rains every day
define logging
his is when people cut down trees and sell it to make money this contributes to deforestation by 2 - 3%.
the amazon is full of valuable hardwood trees such as mahogany, which makes logging extremely tempting to both legal and illegal businesses
describe the structure of rainforests
soils cycle nutrients rapidly to support new growth. But oif the rainforest is cleared they become exposed to excessive leaching and are quickly exhausted of stored nutrients
shrub and ground layer limited to ferns, woody plants, and younger trees because of lack of light. Bacteria and fungi rapidly rot the fallen leaves, dead plants, and animals. thick buttress roots to spread the weight of the towering trees
lower tree canopy shaded less substantial trees waiting to take advantage of the next available light space. interlocking spindly branches and climbing woody creepers from green corridors along which lightweight animals can travel
middle canopy, the most productive layer as each mushroom-shaped crown has an enormous photosynthetic surface of dark, leathery leaves. Drip Tips help them shed water quickly and efficiently
top canopy hardly exposed emergent trees with straight branchless trunks receive the most light
define the Amazon rainforest
the amazon rainforest is the biggest rainforest on earth. in brazil dam construction, deforestation, mining, road building, natural forest fires are the less significant things that add to the deforestation in the Amazon rainforest.
how are rainforests interdependent
the warm and wet climate helps fungi and bacteria on the forest floor to decompose dead plant material rapidly. this makes the surface soil high in nutrients, meaning plants can grow easily
plants pass on their nutrients when eaten by animals. the dense vegetation provides lots of food, so there is high biodiversity. when the animals die, their nutrients are transferred back to the soil, making it richer and encouraging lots of vegetation
many plant and animal species have formed symbiotic relationships ( where they depend on each other for survival)
economic impacts of roads
infrastructure is improved as more roads are built which allows for more transportation around an area. valuable minerals are found in the rainforest and are worth a lot of money.
however, new roads built for logging have opened up areas that were previously too hard to get to, destroying and threatening more of the forest
what is subsistence and commercial farming and how does it contribute to deforestation
subsistence farming is where poor farmers occupy plots of the forest to grow food to feed themselves and their families. They clear the forest and then burn it They grow crops until the soil is exhausted and then move on.
what is 60%-65% of deforestation caused by
cattle ranching is the main cause of deforestation in the amazon- in brazil, there are around 200 million cattle on about 450,000 km^2 of posture
soy is another commercially farmed crop- up to 250,000 km ^2 of farmer forest has been used for its production. tice, corn, and sugar cane are also grown
negative impacts of deforestation (soil erosion).
brazil is losing up to 100 tonnes of topsoil per hectare each year because of soil erosion this creates a negative multiplier effect as this may lead to landslides and flooding in the future
with less tree canopy to intercept rainfall and fewer tree roots to absorb it, more water reaches the soil. this reduces soil fertility as nutrients in the soil are washed away
commercial and subsistence farmers are then forced to find new areas to farm, leading to further deforestation
economic impacts of deforestation
economic development, farming in particular, has brought wealth to many amazonian countries. e.g. in march 2018, brazil exported almost 600 million pounds of beef. brazil is also the worlds second larger exporter of soybeans
the mining industry creates jobs for lots of people e.g. the Buenaventura mining company in Peru employs over 8000 people
logging contributes a huge amount to brazils economy, but it can destroy resources that countries depend on e.g. timber, and reduce the attractiveness of the area to tourists
local Brazilian rubber tappers who extract natural rubber from rubber trees have lost their livelihoods as trees have been cutdown
negative impacts of deforestation (climate change)
Burning the forest releases greenhouse gasses like CO2. This contributes to the warming of our planet via climate change and global warming. In addition, the loss of trees prevents CO2 from being absorbed. The Amazon also helps to drive the global atmospheric system. There is a lot of rainfall there and changes to the Amazon could disrupt the global system.
negative impacts of deforestation (habitats)
the number of different species of living things in a place. if we get rid of the amazon rainforest we are getting rid of the habitats in there which disrupt many ecosystems. however, all of the plants in the amazon rainforest have already helped us with medicines and illnesses. if we are destroying plants that means we could be destroying potential cures used. the loss of biodiversity reduces the uses of the amazon rainforest.
