The Amazon Rainforest Flashcards
What are the Amazons 3 key climatic features?
1) High annual temperature- averaging 25 degrees Celsius to 30 degree Celsius
2) High annual precipitation, reaching up to < 2000m
3) Limited seasonal variation in temperature
Where is 50-60% of the Amazons rainforest recycled from?
Evapotranspiration
Where does significant loss of water occur from in the Amazon river basin?
Loss of water from river flow and export of atmospheric vapor to other regions, this is made good by influx of moisture from Atlantic
Describe the 4 features of evapotranspiration in the Amazon rainforest
- High rates due to high temperatures and dense vegetation
- the evapotranspiration and precipitation feedback loop sustains high rainfall totals
- 30% of incoming rainfall returned by this process
- Moisture lost via this process derives from soil store
What influences rate of run off and when may river discharge peak?
1) Influenced by high rainfall, intensive rainfall and drained soil
2) river discharge may peak for 1 to 2 months of the year
Describe why absolute and relative humidity are high in the Amazon.
High temperatures allow the atmosphere to store large amounts of moisture
Name 3 physical factors impacting stores and flows in the water and carbon cycle
1) Geology
2) Relief
3) Temperature
Describe how geology impacts flows and stores of the water cycle
1) Impermeable and crystalline rock have minimal water storage capacity and lead to rapid run-off
2)Limestone and sandstone store rainwater and slow run off
Describe how relief impacts run off across the Amazon
1) Much of the basin is extensive lowlands, with in lowlands, much of rain moves as overland flow or throughflow into rivers and streams
2) In the west, the Andes provide steep catchment with rapid runoff, widespread inundation across extensive floodplains leads e.g. Pantanal, occur annually and can store water for months, slowing it’s movement into rivers and streams
Explain how temperature can impact flows and stores of the water cycle
Water is recycled between the land surface, trees and atmosphere by transpiration, evaporation and precipitation, these are driven by temperature
Since 1970, almost … of the primary rainforest has been destroyed or degraded
1/5 th
What were the impacts of the April 2014 flooding at the Madeira river?
- Madeira the largest tributary in the Amazon, at Porto Velho, the river reached record levels of 19.68m above normal as floodplains were inundated
- about 20 dead
- about 68,000 families evacuated
-outbreaks of cholera and leptospirosis
Which 4 stores have been most effected by deforestation by reduced water storage capacity?
- Atmosphere
- soil
- trees
- Permeable rock= more rapid run off
Fewer trees mean…
Less evapotranspiration which mean less precipitation
What was the main driver of floods in the upper Madeira basin
Main driver was deforestation in Bolivia and Peru, between 2000-2012, up to 30000km^2 was cleared in Bolivia for subsistence farming and cattle ranching, this led to accelerated run off from steep Andes slopes
Converting rainforest to grassland increases run off by a factor of
27
Explain the importance of tress to the water cycle in the Amazon
Trees extract moisture from their roots, intercept rainfall and release it again to the atmosphere by transpiration. They maintain forest albedo and ground temperatures. This cycle sustains high atmospheric humidity and cloud formation, responsible for convectional rainfall, mass deforestation has therefore, the ability to cause permanent climate change
Explain the importance of tress to the water cycle in the Amazon
Trees extract moisture from their roots, intercept rainfall and release it again to the atmosphere by transpiration. They maintain forest albedo and ground temperatures. This cycle sustains high atmospheric humidity and cloud formation, responsible for convectional rainfall, mass deforestation has therefore, the ability to cause permanent climate change
Future predictions state a … decline in regional rainfall
20%
How much does the Amazon absorb on average, of carbon?
around 2.4 billion tonnes
Average NPP in the Amazon
2500 grams/m^2/year
How much do large forest trees and their roots store on average per ha?
around 180tonnes/ha and a further 40 tonnes/ha
What does the lack of nutrients in Amazonian soils suggest?
The acidic soils can’t host limited carbon and water, despite having such a high NPP and biomass of all terrestrial ecosystems, emphasises the speed with which decomposition and recycling occurs
How much carbon does the Amazon hold as an estimate?
Around 100 billion tonnes locked, it’s a sink of global importnace
