The Amazon Rainforest (Water And Carbon)

Question 1

The Amazon rainforest

Answer 1

• 300 billion trees
• 15,000 species
• covers 5.5 million km(squared) in 9 countries

Question 2

How does the water cycle affect the Amazon

Answer 2

• lots of evaporation over the Atlantic Ocean which contributes to the high rainfall (2000 + mm a year)
• the warm temperatures (27°) increase plant growth which increase evaporation and precipitation
• rainforest has a dense canopy which means interception is high, less water flows into rivers and more is evaporated
• populated by species that are adapted to the high humidity and rainfall

Question 3

How does the carbon cycle affect the Amazon

Answer 3

• carbon sink, stored in soil and vegetation (between 80-120 billion tons)
• increased carbon has led to increased plant growth in the rainforest due to more photosynthesis, this furthermore reduces the carbon in the atmosphere
  HOWEVER
• trees are dying younger so the Amazon may not be a reliable carbon sink

Question 4

Impact of deforestation on the water cycle

Answer 4

• less tree canopy to intercept rainfall so more water reaches the ground, increases surface run off as the soils are saturated s infiltration cannot take place, increases the risk of flooding as the water runs into rivers
• reduces the rates of evapotranspiration : less water is returned to the atmosphere, fewer clouds are formed and rainfall is reduced, increases the risk of drought (can increase temps by 8.9°)
• soils : less trees expose the soil to the sun, it becomes very dry and is at risk of erosion reducing the vegetation that can grow in the forest, also exposes the soil to heavy rainfall which will wash away the toil layer of soil

Question 5

Impacts of deforestation on the carbon cycle

Answer 5

• without roots to hold the soil together heavy rain washes away the nutrient rich soil which transfers carbon to the hydrosphere
• less leaf litter : humus isn’t formed which means soils can’t support new growth, limits the amount of carbon absorbed
• fewer trees means less atmospheric co2 absorbed which enhances the greenhouse effect, photosynthesis pretty much stops until there is new plant growth

Question 6

Impacts of climate change on the Amazon

Answer 6

• droughts, in 2005 and 2010
• the plants and animals are adapted to the moist conditions so may die in dry weather
• forest fires
• scientists predict a 4° temp rise which could kill 85% of the Amazon rainforest

Question 7

Attempts to limit human impacts on the Amazon

Answer 7

Selective logging :
- oldest trees are cut down, if only a few trees are taken the canopy is still there and the structure is kept therefore the forest is able to regenerate

Replanting :
- same variety of trees are replanted, Example : project in Peru replanted 115 acres between 2016 and 2019

Environmental laws :
- Brazilian government aimed to reduce deforestation by 80%, landowners would be fined or arrested if they didn’t obey

Protection :
- national parks and nature reserves , central Amazon conservation complex in Brazil set up in 2003 which allows local people to use the Amazon in a sustainable way