Amazon Rainforest

Question 1

Background

Answer 1

-located in South America
-containers of 300 billion trees
-occupies 68% Brazil
-covers 8.2 million km2
-worlds largest ecosystem
-Amazon river accounts for 15-20% of total freshwater runoff
-forest originated over 55 million years ago

Question 2

Links to water cycle

Answer 2

-over 3000mm of rain
-average temperature of 28 degrees
-75% of total rainfall is intercepted by trees
-25% of all rain evaporates or is returned to the atmosphere by transpiration of plants
-remaining 75% is half used up by plants, and then returned by evapotranspiration and the other half is infiltrated through the soil or flows overland
-deforestation causes increase in surface runoff
-discharges 175,000 cumecs of freshwater into Atlantic each second
-50-80% of water within the Amazon is recycled within the ecosystem rather than flowing straight back out of it

Question 3

Links to the carbon cycle

Answer 3

-plants conduct photosynthesis, releasing oxygen and locking in carbon
-stores 20% of all biomass stored carbon on the planet
-only coral fixes a larger amount of carbon that tropical rainforests
-deforestation leads to soils being unconsolidated and therefore spoil erosion -> removes the soil stored carbon and can wash it into the water system
-age of many plants mean they’re long term stores
-regulates global atmospheric carbon levels

Question 4

Links to environmental change and human activity

Answer 4

-up to 1960, shifting subsistence cultivation by indigenous groups had little impact
-late 1960s Brazilian government encouraged colonisation and sponsored large scale projects to exploit resources
-road construction in order to allow for logging
-Amazon rainforest has lost about 17% of its primary rainforest in the last 50 years
-80% of lost forest is due to cattle ranching

Question 5

CONTINUE