The Amazon Rainforest Flashcards
How large is the rainforest?
6 million km2
How much of the rainforest is in Brazil?
70%
What other countries does the rainforest extend into?
Peru, Ecuador, Venezuela, Columbia, Bolivia, Guyana
What are the average annual temperatures like?
High - 25 to 30 degrees
What are the seasonal differences in temperature?
Small
What is the result of cloud cover?
Temperatures kept to 33 degrees max
What is the average rainfall?
over 2000mm
How much precipitation is recycled by evapotranspiration?
50-60%
Where is water lost?
River flow and export of atmospheric vapour to other regions
Where does the inward flux of moisture come from?
Atlantic Ocean
How is precipitation distributed throughout the year?
Evenly
What type of rain is it?
High intensity convectional rainfall
How much rain is intercepted by trees?
10% - a lot
Intercepted rain accounts for what % of evaporation?
20 - 25%
Why is evapotranspiration high?
High temperatures, abundant moisture, dense vegetation
What feedback loop is strong?
evapotranspiration-precipitation
Where doe most evaporation come from?
Intercepted moisture from leaf surfaces
How do plants replace lost moisture from transpiration?
Soil via the roots
Why is run-off rapid?
high and intense rainfall and well-drained soil
What causes a short peak in river discharge?
seasonal distribution of rainfall
What forms of humidity are high?
absolute and relative (the ratio of mass of vapour in air against how much is needed to saturate it)
Why is there significant water storage in soil?
High rainfall and deep soil
What role do trees play in the water cycle?
absorb and store water then release it via transpiration
What geology is dominant?
impermeable crystalline rocks
What is the result of impermeable rocks?
minimal water storage capacity so rapid run off
Examples of porous rocks:
limestone and sandstone
Describe the relief
mostly lowland with gentle relief but steep Andes range in the west
What is the effect of lowland on the water cycle?
overland flow and throughflow
What is the effect of the Andes on the water cycle?
rapid run off
Example of a floodplain
Pantanal
What do floodplains do?
store water
What is the result of high temperatures on the water cycle?
high evapotranspiration
What is the result of strong convection on the water cycle?
high humidity, thunderstorm clouds, intense precipitation
What processes continually cycle water?
evaporation, transpiration, precipitation
How much is was deforested on average each year between 1970 and 2013?
17,500 km2
How much primary forest has been destroyed since 1970
1/5
What has happened to the rate of deforestation in recent years?
slowed
What is the result of converting rainforest to grassland on the water cycle?
increases run off by a factor of 27
How much of rainfall that falls on grassland goes into rivers?
half
Why are trees crucial to the water cycle?
extract moisture from soil, intercept rainfall, release moisture to atmosphere, stabilise albedo and ground temperatures
What do trees help sustain?
humidity, clouds, convectional rainfall
How much is regional rainfall predicted to fall by due to deforestation?
20%
What other forests are affected by deforestation?
forests hundreds of km downwind of degraded sites
What is the Madeira?
the largest tributary of the Amazon
When did the Madeira flood?
April 2014
How much higher was the river at Port Velho?
19.68m
How many died in the 2014 floods?
60
How many families were evacuated in the 2014 floods?
68,000
What diseases emerged in the 2014 floods?
cholera and leptospirosis
What did human activity in the Upper Madeira basin do to the water cycle?
modify stores and flows
What flow became more rapid due to deforestation in the Madeira?
run-off
What is a physical cause of the 2014 floods?
torrential rain
How much Bolivian rainforest was lost in 2000-2012?
30,000 km2
Why was Bolivian rainforest destroyed?
subsistence farming and cattle ranching
Why was the location of the deforestation important?
it was on the steep slopes of the Andes so run off was accelerated
Why is the climate ideal for plant growth?
humid and warm
what is the NPP?
2500 g/m3/year
what is the biomass?
400-700 tonnes/ha
How much carbon does the entire rainforest absorb each year?
2.4 billion tonnes
What is the result of warm humid conditions on the carbon cycle?
quick decomposition and quick release of CO2
What is the result of photosynthesis on the carbon cycle?
High rates of carbon fixation
Why do soils only contain limited carbon?
they are leached and acidic
What is the evidence that organic matter is recycled rapidly?
Soils support high NPP and biomass despite containing limited carbon and nutrients
How much carbon is in the Amazon?
100 billion tonnes
Out of all the carbon in the Amazon, how much is in biomass?
60%
What stimulates NPP?
high temperatures, rain, sunlight
Amazon accounts for how much of global NPP?
15-25%
How much carbon is released through decomposition by the Amazon each year?
1.7 billion tonnes
What is geology dominated by?
metamorphic and igneous rock with carbonates largely absent
What are the significant carbon stores for the slow carbon cycle in the Amazon?
limestone in the west
What does deforestation do to the carbon biomass store?
exhausts it
what contains less carbon than trees?
croplands and pasture
What is the biomass of grassland?
16.2 tonnes/ha
What is the biomass of soya?
2.7 tonnes/ha
What happens to soil after deforestation regarding the carbon cycle?
supports less decomposers so reduces the flow of carbon from soil to atmosphere
How does deforestation destroy the main nutrient store?
trees are the main nutrient stores
What happens to the remaining nutrients on the soil?
washed away
What is the first category of management strategy?
protection of primary forest so far unaffected
What is the second category of management strategy?
Reforestation of areas destroyed by farming, logging, mining
What is the third category of management strategy?
improving agricultural techniques to make permanent cultivation possible
How have indigenous people lived sustainably for 1000s of years?
Hunter-gatherers and shifting cultivators
When did the Brazilian government start establishing conservation areas?
1988
What size area do conservation areas cover?
20X the size of Belgium
By 2014 what % of the Brazilian Amazon was national parks, wildlife or indigenous reserves?
44%
Where is the Parica project?
Rondonia (western Amazon)
What is the Parica project?
a sustainable forestry scheme
What does the Parica project aim to do?
develop a 1000km2 commercial timber plantation on government owned deforested land
How many fast growing hardwood seedlings are to be planted by the Parica project?
20 million
Where will the Parica project plant is seddlings?
4000 small holdings
What is an issue with the Parica project?
monoculture and can’t replicate biodiversity of primary forest
What is good about the Parica project?
sustainable, sequesters carbon, reduces CO2 emissions, re-establish water and carbon cycles, reduces run-off and loss of nutrients
What is the name of an indigenous tribe?
the Surui people
What do the Surui people do?
plant seedlings in deforested areas around their villages
What is the purpose of the Surui planting seedlings?
provide them with timber and a sustainable source of income
The Surui are the first indigenous group in Amazonia to join what?
the UN’s Reducing Emissions from Deforestation and Degradation (REDD) scheme
What TNC bought 120,000 carbon credits off the Surui in 2013?
Natura
Why is permanent cultivation not possible?
the low fertility of soils
how can soil fertility be maintained?
rotational cropping and combining livestock with arable
how can the rainforest support large human populations?
human-engineered soils made from charcoal and manure
What does charcoal do?
attract microorganisms and fungi so soil retains long-term fertility
What would permanent cultivation stop?
further deforestation and carbon emissions
