Amazon rainforest Flashcards
Where is the Amazon rainforest located?
The Amazon rainforest is located in South America where 60% of the rainforest is located in Brazil
What are some key facts about the Amazon rainforest?
- Important for carbon cycles
- Large carbon sink and stores 90-140 billion tonnes of carbon to keep plants at a dynamic equilibrium
- World’s largest tropical rainforest and covers 40% of South America’s landmass
- 15,000 species
- 300 billion trees
- Stores 1/5 of the carbon in Earth’s biomass
- The Amazon rainforest has lost 17% of its rainforest in the last 50 years due to cattle
- In a year, the Amazon absorbs 2.2 billion tonnes of Co2 and emits 1.9 billion, so its a carbon sink
What is an important fact about the Amazon rainforest?
The Amazon rainforest is the size of a football pitch of land and is being cut down every minute due to deforestation
Why is the water cycle important in the Amazon rainforest?
- The water cycle causes the Amazon to be very wet, lots of evaporation, and the wet air goes to the Amazon. This causes high rainfall
- Warm temperatures cause high evaporation, increasing precipitation
- The Amazon has a dense canopy, increasing interception. Less water flows to rivers at a slower rate
Why is the carbon cycle important in the Amazon rainforest?
- The Amazon stores carbon in vegetation and soil, thus a large carbon sink
- Increased concentrations of Co2 in the atmosphere has led to more photosynthesis
- The Co2 sequestrated has increased, making it a carbon source
- Carbon fertilisation - The increased atmospheric Co2 stimulates biomass growth. As plants grow faster, they die sooner.
What human activities affect the Amazon rainforest?
- Mining
- Logging/deforestation
- Environmental groups
- Vegetation change
- Commercial farming/cattle ranching
- Infrastructure
- Settlements
How does mining affect the Amazon rainforest?
- Mines extract minerals such as iron ores, gold, and diamonds. Extracting these resources is a destructive activity that damages the rainforest and causes problems for people living nearby
How does logging/deforestation affect the Amazon rainforest?
- Wood from the Amazon for paper.
- Logging is either selective or clear cutting
- Selective logging - loggers choose wood that is highly valued, such as mahogany
- Clear cutting - loggers cut down all trees
How do environmental groups affect the Amazon rainforest?
- Preserve the rainforest’s natural state
How does vegetation change affect the Amazon rainforest?
- Loss of forests caused by deforestation and climate change
- Climate change affects temperatures and droughts
- Droughts and high temperatures kill trees
How does commercial farming/cattle ranching affect the Amazon rainforest?
- Cattle ranching is the biggest cause of deforestation
- 80% of deforested areas in Brazil are used for pasture
- Over 70% od deforestation is for palm oil. They exploit the land for money
- Cattle industry rapidly growing since 1970’s
- Since 2003, Brazil has topped the world’s beef exports
- Between 1996 and 2006, an area of Portugal was carved
How does infrastructure affect the Amazon rainforest?
- The Trans Amazonian Highway is 4,000 km long and is the longest highway in Brazil. This has caused further deforestation
How has settlements affected the Amazon rainforest?
- The Brazilian government has encouraged people in cities to move to the Amazon by giving parcels of land
- They offered land and paid them to settle. More settlers have cleared the forest
What are the human impacts on the water cycle in the Amazon?
- In deforested areas there is no canopy to intercept rainfall, so more water reaches the ground
- There is too much water, so there is surface runoff to rivers, increasing risk of flooding
- Deforestation reduces evapotranspiration - This means less water vapour reaches the atmosphere, fewer clouds and less rainfall. This increases droughts.
What are the human impacts on the carbon cycle in the Amazon?
- Without roots to hold the soil together, heavy rainfall washes the nutrient rich top layer of soil, transferring carbon in the soil to the hydrosphere.
- There is less leaf litter, so no humus. There is less plant growth, limiting the carbon absorbed
- Trees remove Co2 from the atmosphere and store it, so fewer trees mean more atmospheric Co2 which enhances the greenhouse gas effect (GHG) and global warming
