Amazon Rainforest Flashcards
How many trees does the Amazon have? How many species? What does this result in?
300 billion trees
15,000 species
Both of these store 1/5 of all the carbon in the Earth’s biomass.
Location and size of the Amazon?
Today’s rainforest covers 5.5km2 abs is spread across nine countries in South America.
The Amazon is a carbon sink. How much carbon does it store?
80 - 120 billion tonnes.
What’s the negative feedback system in the Amazon carbon cycle?
The Amazon has been increasing in above ground biomass by 0.5% per year, and the rising productivity of tropical forests is due to sequestering of increased CO2 concentrations in the atmosphere.
This offsets rising atmospheric CO2 levels.
What’s the sad thing about the Amazon carbon cycle?
The Amazon forest is losing its capacity to absorb CO2 from the atmosphere.
From a peak of 2bn tonnes of CO2 each year in the 1990s, the net uptake by the forest has halved. And now been overtaken by fossil fuel emissions in Latin America.
Why has there been a surge in dying trees in the Amazon?
Because for the Amazon basin, an increase in atmospheric CO2 levels led to a growth spurt for the Amazon’s trees; in time however, the growth stimulation feeds through the system, causing trees to grow faster, and therefore die younger.
This has led to a surge in the rate of trees dying across the Amazon.
Of the rainfall that is evapotranspired, how much of this falls as rain again?
48%.
How much of the rainfall actually reaches the sea?
30%
The rest us caught up in the constant closed system loop.
Between 2000 and 2007, the Amazon was deforested at a rate of…
19,368km2 per year.
The removal of forest was done using slash and burn techniques which:
- reduces the retention of humidity in the soil’s top layer down to a depth of 1m
- increases the albedo and temperature
- reduces porosity if soil, causing faster rainfall drainage. Erosion and silting of rivers and lakes
Any moisture that evaporates from deforested areas forms…
Shallow cumulus clouds which usually do not produce rain.
Whys there less rain after deforestation?
- any moisture that evaporates from deforested areas forms shallow cumulus clouds which usually do not produce rain
- forests emit salts and organic fibres along with water when they transpire. These act as condensation nuclei and assist in cloud and rain. This loss inhibits the formation of clouds and reduces rainfall.
