Amazon Flashcards
Where is the Amazon
Between the tropics of Cancer and Capricorn
Majority lies in Brazil
Remainder in Peru and Columbia
How many square miles does it cover
2.1 million
How much of S.America does it cover
40%
How much of the Earth’s surface does it cover
6%
How much of global photosynthesis does it account for
30-50%
Annual rainfall
2000+mm
How many of the worlds species is it home to
50%
Why are inputs into the local water cycle so high
High levels of precipitation
Due to low pressure and high humidity
How much precipitation does the canopy intercept
75%
How much of its own precipitation does the Amazon basin produce
1/3
Due to recycling of evapotranspiration
How much of the primary rainforest has been lost in the last 50 years
17%
80% of which is due to clearance for cattle ranches
What happens to the cleared areas of the forest in terms of the water cycle
Reduced evapotranspirarion
Means air is less moist
Results in less cloud cover and therefore less precipitation
No trees results in no interception and therefore a very small lag time
Water leaves the area as overland flow so less is returned to the atmosphere locally
Increased rates of runoff means an increased risk of flooding
What do estimates suggest the regional rainfall could decrease by and what is this due to
20% decrease
Due to deforestation which means less evapotranspiration and more water is lost from the local system
How many tons of CO2 are absorbed and emitted in 1 year
- 2 billion absorbed
1. 9 billion emitted
Where is 40% of the carbon in the Amazon stored
Underground
Is the Amazon a source or sink of carbon
Sink
What has increased atmospheric levels of CO2 led to
Increased productivity as the vegetation is able to access more CO2 for photosynthesis
Therefore amount of carbon sequestration increases
What is the second largest anthropogenic source of CO2
Deforestation after burning of fossil fuels
What is the rate at which the forest has been decreasing at and since when
0.3%
Since 2000
In terms of the carbon cycle, what happens after parts of the forest are burnt away
Ash is washed into the soil
Increasing the soil carbon content in the short term
Some of this carbon will leave the system via runoff
Rain washes away the top layer of nutrient rich soil
4 attempts to limit human impacts
- Selective Logging
Only the oldest trees are felled
This is less damaging to the forest as it means the area can keep its structure
Soil doesn’t become exposed as the canopy remains intact
Rainforest is able to regenerate and therefore the impacts on the W+C cycles is less - Replanting
New trees are planted to replace the ones being cut down
Peru plans to restore 3.2 million hectares by 2020 - Environmental Law
Ban the use of wood that was obtained unsustainably
Laws ban excessive logging
Laws control land use e.g Brazilian land owners have to have 50-80% of their land as forest - Protection
Many countries have set up reserves and national parks
Damaging activities are monitored within these parks
