Amazon rainofret Flashcards
(29 cards)
Amazon - River Basin
Water losses from the Amazon Basin result from river flow and export of atmosphere vapour to other regions
This loss is made good by an inward flux of moisture from the Atlantic Ocean
Features of TRF
High precipitation High evapotranspiration Humid Hot Lots of vegetation on all levels
Physical factors (Geology)
Impermeable catchments have minimal water sotrage capacity resulting in rapid run-off
Physical factors (Relief)
Most of the Amazon Basin comprises extensive lowlands in areas of gentle relief water moves across the surface for horizontally through the soil (through flow) to streams and river in the west.
Physical factors (Temperature)
High temperature throughout the year generate high rates of evapotranspiration, Convection is strong leading to high atmospheric humidity
What is the main store of nutrients in TRF
Biomass
Climate features
Precipitation is higher in jan to may than jun to sept
What are the consequences of the TRF climate
High NPP
Rapid decomposition
Rapid nutrient uptake
What is the geology like
Lack of carbonates
People and the Amazon
Indigenous people have lived sustainabily in the TRF for thousands of years
Hunter-gatherers and shifting cultivation
Name 3 strategies to manage the Amazon
Protection through legalization
Reforest areas
Improve agricultural techniques
Parica Project
Western Amazon
Sustainable forestry scheme aims to develop commercial timber plantation on government owned deforested land
Surui people
Participate is a scheme to protect primary rainforest on tribal land from further illegal logging and reforest areas degraded by deforestation
What is the problem with improved agriculture
Farming has been the main cause of deforestation in Ammonia
Permanent cultivation proved unsustainable
Examples of Diversification
Crop rotation
Combining arable and livestock operations
Anthropogenic soil in the Amazon
European explorers observed that the Amazon rainforest supported a high population as late as the 16th century
Dark soils
Human engineered
Inputs of charcoal, waste and human manure
Charcoal attraction micro-organisms and fungi
Char-wood is porous
Prevents leaching
Future of farming
Scientists are currently investigating these dark soils
If they can be successful recreated they would allow intensive and permenant cultivation
This would reduce deforestation and carbon emissions
How much does the amazon cover
The Amazon forest covers an estimated 5.3 million sq km and holds 17% of the global terrestrial vegetation carbon stock.5
Carbon in south America
showed that around 1% of all the tree species in the Amazon account for half of the carbon locked in the vast South American rainforest.
Amazon as a carbon sink
Dead Amazonian trees (which account for around 20% of above ground biomass5) emit an estimated 1.9 billion tons (1.7 billion metric tons) of carbon to the atmosphere each year. In a normal year, the Amazon rainforest absorbs about 2.2 billion tons (2 billion metric tons) of carbon dioxide. This means that untouched tropical forests act as a SINK for carbon.
Average discharge of water into the sea
The average discharge of water into the Atlantic Ocean by the Amazon is approximately 175,000 m3 per second, or between 1/5th and 1/6th of the total discharge into the oceans of all of the world’s rivers.
Rio Negro
The Rio Negro, a tributary of the Amazon, is the second largest river in the world in terms of water flow, and is 100 meters deep and 14 kilometers wide near its mouth at Manaus, Brazil.
Rainfall in the basin
Average rainfall across the whole Amazon basin is approximately 2300 mm annually. In some areas of the northwest portion of the Amazon basin, yearly rainfall can exceed 6000 mm. 3
Only around 1/3 of the rain that falls in the Amazon basin is discharged into the Atlantic Ocean.