Amazon Rainforest Flashcards
Basic Facts about the rainforest
The Amazon is the world’s largest tropical rainforest and covers 40% of the South American landmass.
It has a hot, very wet climate and the vegetation is very dense.
Many groups of indigenous people lie in the Amazon Rainforest
It’s home to up to 1 million plant species, over 500 species of mammals and over 2000 species of fish. The Amazon is also home to many endangered species, including the Amazon manatee(an aquatic mammal), black caiman(a reptile) and the pirarucu(a fish)
Water cycle relating to the Amazon Rainforest
1)The water cycle causes the Amazon to be very wet-there is a lot of evaporation over the Atlantic Ocean, and the wet air is blown towards the Amazon. This contributes to the Amazon’s very high rainfall.
2)Warm temperatures mean that evaporation is high in the rainforest itself, which increases the amount of precipitation
3)The rainforest has a dense canopy- this means that interception is high. As a result, less water flows into rivers than might otherwise be expected, and it does so more slowly.
4)The water cycle affects the Amazon environment-it is populated by species that are adapted to high humidity and frequent rainfall.
Carbon Cycle relating to Amazon Rainforest
1)The Amazon rainforest stores lots of carbon in its vegetation and soil, so it’s a carbon sink.
2)The increasing concentration of CO2 in the atmosphere has led to increased productivity in the Amazon Rainforest because the vegetation is able to access more CO2 for photosynthesis- the amount of biomass has been increasing
3)As a result, the amount of CO2 sequestered by the amazon rainforest has increased, making it an even more important carbon store.
4)However, it has been suggested that although trees are growing more quickly, they’re also dying younger
5)As a result, we may not be able to rely on the Amazon Rainforest to continue to be such an effective carbon sink in the future
Human Activities that affect the water cycle
Deforestation- In deforested areas there is no tree canopy to intercept rainfall, so more water reaches the ground surface. There is too much water to soak into the soil. Instead the water moves to rivers as surface runoff, which increases the risk of flooding
Deforestation reduces the rate of evapotranspiration-this means less water vapour reaches the atmosphere, fewer clouds form and rainfall is reduced. This increases the risk of drought.
Human Activities that affect the carbon cycle
Deforestation- Without roots to hold the soil together, heavy rain washes away the nutrient-rich top layer of soil, transferring carbon stored in the soil to the hydrosphere.
Deforestation means that there is less leaf litter, so humus isn’t formed. The soil cannot support much new growth, which limits the amount of carbon that is absorbed.
Trees remove co2 from the atmosphere and store it, so fewer trees means more atmospheric co2, which enhances the greenhouse effect and global warming
Climate change affects the Amazon.
Climate change can severely impact tropical rainforests. In some areas temperature is increasing and rainfall is decreasing, which leads to drought.The Amazon has severe droughts in 2005 and 2010.
Scientists predict that a 4 degrees temperature rise could kill 85% of the amazon rainforest.This would result in lots of carbon being released into the atmosphere as the dead material decomposed, and less carbon dioxide being taken in from the air by trees for photosynthesis.
Climate change affects the Amazon.-droughts
Plants and animals living in tropical rainforests are adapted to moist conditions, so many species die in dry weather. Frequent or long periods of drought could lead to extinction of some species. Drought can also lead to forest fires, which can destroy large areas of forest, releasing lots of co2 into the atmosphere.
Climate change affects the Amazon.
Scientists predict that a 4 degrees temperature rise could kill 85% of the amazon rainforest.This would result in lots of carbon being released into the atmosphere as the dead material decomposed, and less carbon dioxide being taken in from the air by trees for photosynthesis.
Attempts to limit human impacts
Selective logging-
Only some trees are felled
This is less damaging to the forest than felling all the trees in an area. If only a few trees are taken from each area the forest structure is kept-the canopy is still there and the soil isn’t exposed.
This means the forest is able to regenerate, so the impact on the carbon and water cycle is small.
Attempts to limit human impacts
Environmental law-
Laws that ban the uses of wood from forests that are not managed sustainably
Laws that ban excessive logging
Lwas that control land uses,e.g. the Brazilian forest code says that landowners have to keep 50-80% of their land as forest
