Water and Carbon in the Amazon
- The Amazon Basin is the largest rainforest and one of the most biodiverse
- 300 billion trees and 15,000 species store 1/5th of the planet’s biomass carbon
- Spread across 9 countries with 34 million people dependent on it
Carbon
- Stores 76 billion tons of carbon
- Forms a carbon sink of 1-3 GtC/year (600 million tonnes a year – much less than 2 billion
tonnes in 1990s)
- Has been increasing in above-ground biomass around 0.5% per year
- The rising productivity and increased growth of Amazon trees of the rainforest is because of
the increased atmospheric CO2 concentrations
- Causes negative feedback that seems to neutralise the increasing CO2
- However, more atmospheric CO2 = trees grow faster and die younger = increased amount of
dying trees in the Amazon
- Warm and wet climate = good for plant growth and photosynthesis
- Wood = 50% carbon
- Plant respiration returns CO2 into atmosphere = increases plant productivity = biomass
increases
Water
- Average discharge into Atlantic Ocean = approximately 175,000m3/s
- The Rio Negro, a tributary of Amazon, is the second largest river in the world in terms of water
flow (100m deep and 14km wide at mouth at Manaus, Brazil)
- Average rainfall across basin = 2,300mm annually, but can exceed 6,000mm.
- ½ of this rainfall is intercepted by canopy and re-evaporates
- More water evaporates from the ground and rivers or released into atmosphere by
transpiration from plants
- Some water infiltrates soil and is stored temporarily
- Of all water that is evapotranspired to atmosphere = 48% falls as rain again and 30% reaches
the sea. The rest is caught in constant closed system loop
Drivers of Change
- The Amazon Basin is the largest rainforest and one of the most biodiverse
- 300 billion trees and 15,000 species store 1/5th of the planet’s biomass carbon
- Spread across 9 countries with 34 million people dependent on it
Carbon
- Stores 76 billion tons of carbon
- Forms a carbon sink of 1-3 GtC/year (600 million tonnes a year – much less than 2 billion
tonnes in 1990s)
- Has been increasing in above-ground biomass around 0.5% per year
- The rising productivity and increased growth of Amazon trees of the rainforest is because of
the increased atmospheric CO2 concentrations
- Causes negative feedback that seems to neutralise the increasing CO2
- However, more atmospheric CO2 = trees grow faster and die younger = increased amount of
dying trees in the Amazon
- Warm and wet climate = good for plant growth and photosynthesis
- Wood = 50% carbon
- Plant respiration returns CO2 into atmosphere = increases plant productivity = biomass
increases
Water
- Average discharge into Atlantic Ocean = approximately 175,000m3/s
- The Rio Negro, a tributary of Amazon, is the second largest river in the world in terms of water
flow (100m deep and 14km wide at mouth at Manaus, Brazil)
- Average rainfall across basin = 2,300mm annually, but can exceed 6,000mm.
- ½ of this rainfall is intercepted by canopy and re-evaporates
- More water evaporates from the ground and rivers or released into atmosphere by
transpiration from plants
- Some water infiltrates soil and is stored temporarily
- Of all water that is evapotranspired to atmosphere = 48% falls as rain again and 30% reaches
the sea. The rest is caught in constant closed system loop
Drivers of Change
