Amazon Rainforest Flashcards
Water cycle in the Amazon rainforest
- precipitation, high annual average >2000mm
- evapotranspiration, High temperatures = high rates of evapotranspiration; 50%-60% precipitation recycled as
evapotranspiration - Run-off, Rapid run-off due to high and intense rainfall
- Atmosphere, Large stores of water due to high temperatures
- Soil/ground, High precipitation causes significant water stores in soils and aquifers
- Vegetation, each tree has a crucial role in the cycle, absorbing, storing and transpiring water
Carbon cycle in Amazon rainforest
- Atmosphere, Rapid exchanges to atmosphere; decomposition rapid, so quick release of carbon
- Soil/ground, Limited stores of carbon as organic matter quickly broken down and recycled
- Photosynthesis, Sequestration of CO, very high
- Vegetation, High NPP (2500 g/m?/yr); high biomass; rainforest trees store 180 tonnes
C/a in the tree, 40 tonnes C/a in the roots,
Physical factors affecting the water cycles in the Amazon rainforest
- geology
- temperature
- relief
How does the geology affect the water cycle in the Amazon rainforest
- Two contrasting geologies.
- Large parts of Amazon catchment impermeable meaning minimal storage and high run-off.
- Porous limestone in some areas, store water and slow run-off.
How does the temperature affect the water cycle
- High temperatures cause high evapotranspiration.
- Strong convection.
- Water continually cycled between land, trees and atmosphere.
How does relief affect the water cycle
- High run-off due to steep catchments in the west.
- Extensive, gentle lowland helps to store water.
- More throughflow.
Physical factors affecting the carbon cycles in the Amazon rainforest
- geology
- temperature
- biomass
How does geology affect the carbon cycle
- Two contrasting geologies.
- Little storage of carbon in igneous and metamorphic rock.
- Limestone outcrops are significant stores of carbon.
How does temperature affect the carbon cycle
- High temperatures and guaranteed sunlight cause much photosynthesis.
- Promotes rapid decomposition.
How does biomass affect the carbon cycle
- Main carbon store.
- Absorbs 2.4 billion tones of CO, per year.
- Stores 60% in trees; 40% in roots and soil.
Human factors affecting the water cycle
- Deforestation increases ground temperatures but reduces cloud formation and can lead to permanent climate change.
- Deforestation for subsistence farming and cattle ranching in the Upper Madeira Basin has led to reduced water storage in trees, soil, geology and the atmosphere.
Total run-off has increased by a factor of 27 and run-off speeds have also increased. In 2014, flooding in Porto Velho killed 60 and 68,000 people had to be evacuated.
Human factors affecting carbon cycle
- Deforestation reduces the amount of carbon stored as biomass and reaching the soil.
- Even if trees are replaced by crops or pasture, the carbon store is greatly reduced.
- There are also fewer decomposers in deforested areas, which slows carbon flow to the atmosphere.
Strategies to manage change in the water and carbon cycle
- protection through legislation
- deforestation projects
- improved agriculture techniques
Examples of the protection through legislation strategy
- Forest conservation areas set up.
- by 2015, 44% of Brazilian Amazon protected areas where farming is banned
Examples of the deforestation projects strategy
Parica Project - sustainable forestry scheme producing commercial timber, although a monoculture scheme does help to sequester carbon and reduce run-off.
REDD scheme - payment made via carbon credit to tribes like the Suri. They protect the rainforest and stop logging in return for credits which companies can buy.
Examples of improved agriculture techniques as a strategy.
Soil fertility can improve through diversification, e.g. rotational cropping.
Human engineered ‘dark soils’ under investigation to assist more intensive cultivation.
