Amazon - Water And Carbon

Question 1

Background

Answer 1

• south america
• contains over 300 million trees
• cover 68% of Brazil and parts of Peru, bolivia, columbia, ecuador, venezuela etc
• covers 8.2million km2
• world’s largest rainforest ecosystem
• largest example of freshwater runoff = 15-20%
• originated over 55 million years ago
• soils are fetilised partly by phophorus from sahara’s bodele region

Question 2

Links to water cycle

Answer 2

• over 3000mm of rain a year
• avergae temp of 28C causing humid conditions
• 75% of total rain is intercepted by trees
• 25% of all reain evaporates or is returned to the atmosphere via transpiration
• of the remaining 75% half is used by plants and returens to the atmosphere
• other 50% is infiltrated
• deforestation may cause increases in surface runoff
• discharges 175,000 cumecs of freshwater into atlantic each second
• moisture released into the atmosphere impacts rainfall in USA, EU, SEA
• 50-80% of the water within the Amazon is recylced within the ecosystem

Question 3

Links to the carbon cycle

Answer 3

• plants do photosynthesis releasing o2 and trapping CO2
• knowing as ‘the lungs of the earth’
• stores 20% of all biomass on planet
• only coral fixes a larges amount of carbon than tropical rainforests
• deforestation leads to soils being unconsolidatetd and so soil erosion
• soil erosion leads to carbon being washed away
• age of many plants in the rainforest means they are long-term carbon store
• regulate global atmospheric carbon levels

Question 4

Links to environmental change and human activity

Answer 4

• up to 1960, shifiting subsistence cultivation by indigenous groups had little impact on the biome
• 1960s Brazilian government encouraged colonisation of large scale projects that exploited land
• it has lost approximately 17% of its primary rainforest in the last 50 years = 80% cattle ranching
• dought in 2005 and 2010
• 2010 drought - lowered the rio negro, islotaing local people who used it for transport
• forest fires release a large store of carbon
• deforestaion impacts albedo and transpiration
• large hydroelectric dams
• crops planted in deforested areas will fix some carbon and evapotranspire
• destruction of amazons coastal mangroves - rapid transfers in water cycle
• by 2080 current species wont be viable in the amazon due to temp and the cycle will shut down