Amazon rainforest case study
Location and basics.
World’s largest rainforest
Central northern south America
5.5 million kilometres squared across 9 countries e.g. Brazil, Bolivia,
Ecuador
Climate
Temperatures peak in sept- nov (27.5 degrees)
Rainfall peaks in march-April, lowest in aug and sept (around 100 mm
when temps are high)
Temp and rainfall follow a pattern opposite to each other
Fauna/flora
300bn trees
15,000 species
Soil contains 4-9kg of carbon in the upper 50 cm
Fertile soil
Animals e.g. toucan, tree frog, spider monkey, green anaconda, piranha
Deforestation has ecological consquences lack of trees, affect fish who
eat fallen fruit.
Water cycle basics
2,300 mm of rain annually
Northwest basin can receive up to 6000 mm
75% of all rain is intercepted and re-evaporated
Around 30% reaches the ground
48% falls again as rain
Of water which reaches the ground 50% infiltrates into soil and 50% is
used by plants
Shallow buttress roots because nutrients are quicjly recycled and trees
don’t have to search for moisture
Carbon cycle basics
Stores 1/5 of all carbon – 50% in biomass and 50% in soil
Wood is about 50% carbon
80-120 bn tonns of carbon in amazon
Carbon fixing (change of carbon from atmospheric to biosphere) is very
quick in rainforests, second only to coral reefs.
Deforestation – causes and impacts
Causes:
HEP – tucuri dam
, Road construction – Trans-Amazon Highway
Mining – Carajas
Farming – soya, cattle account for 80% of deforestation in Brazil
Settlement growth – Manaus
Logging -japan’s demand for hardwood grown in Amazonia has risen to 11
million m cubed a year.
Impacts of human activities/ deforestation
Social Economic Environmental
More jobs – better Income – atleast Chemicals from mining
quality of life (links to 50,000 people are
all human activity) employed in gold Eventual loss of
mining in peru resources
Conflict – in 2009 over
30 Peru natives were National economy – in Climate change
killed in riots over 2008 Brazil made over
rainforest destruction $6.9bn from cattle Leads to increase in
trading temps – kills more
Traditional livelihoods trees
destroyed e.g. rubber
tappers More flash floods
Factors that impact change on the water cycle
River discharge changes – changes in precipitation, change in river
sediment
Deforestation – changed evaporation rates, reduces cloud cover and rain.
Veg change – 3.6 million hectares destroyed annually, change can be from
deforestation or cc, soil washed away- harder for plants to grow.
Climate change – expecting a 2-3 degrees increase by 2050, there will be
a 20-40% loss of rainforest in next 100 years if temps increase by 2
degrees. Positive feedback – less rain less plants less evap less
rain
River regimes – seasonal discharge changes, reducing precipitation means
lower discharge
Soil – exposed soils
Changes in carbon cycle
Deforestation . albedo affect, reduced ps
Slash and burn – deforestation impacts, rapid return of carbon to
atmosphere. Farmers originally used the ash as a fertiliser but the area
quickly loses fertility.
Location and basics.
World’s largest rainforest
Central northern south America
5.5 million kilometres squared across 9 countries e.g. Brazil, Bolivia,
Ecuador
Climate
Temperatures peak in sept- nov (27.5 degrees)
Rainfall peaks in march-April, lowest in aug and sept (around 100 mm
when temps are high)
Temp and rainfall follow a pattern opposite to each other
Fauna/flora
300bn trees
15,000 species
Soil contains 4-9kg of carbon in the upper 50 cm
Fertile soil
Animals e.g. toucan, tree frog, spider monkey, green anaconda, piranha
Deforestation has ecological consquences lack of trees, affect fish who
eat fallen fruit.
Water cycle basics
2,300 mm of rain annually
Northwest basin can receive up to 6000 mm
75% of all rain is intercepted and re-evaporated
Around 30% reaches the ground
48% falls again as rain
Of water which reaches the ground 50% infiltrates into soil and 50% is
used by plants
Shallow buttress roots because nutrients are quicjly recycled and trees
don’t have to search for moisture
Carbon cycle basics
Stores 1/5 of all carbon – 50% in biomass and 50% in soil
Wood is about 50% carbon
80-120 bn tonns of carbon in amazon
Carbon fixing (change of carbon from atmospheric to biosphere) is very
quick in rainforests, second only to coral reefs.
Deforestation – causes and impacts
Causes:
HEP – tucuri dam
, Road construction – Trans-Amazon Highway
Mining – Carajas
Farming – soya, cattle account for 80% of deforestation in Brazil
Settlement growth – Manaus
Logging -japan’s demand for hardwood grown in Amazonia has risen to 11
million m cubed a year.
Impacts of human activities/ deforestation
Social Economic Environmental
More jobs – better Income – atleast Chemicals from mining
quality of life (links to 50,000 people are
all human activity) employed in gold Eventual loss of
mining in peru resources
Conflict – in 2009 over
30 Peru natives were National economy – in Climate change
killed in riots over 2008 Brazil made over
rainforest destruction $6.9bn from cattle Leads to increase in
trading temps – kills more
Traditional livelihoods trees
destroyed e.g. rubber
tappers More flash floods
Factors that impact change on the water cycle
River discharge changes – changes in precipitation, change in river
sediment
Deforestation – changed evaporation rates, reduces cloud cover and rain.
Veg change – 3.6 million hectares destroyed annually, change can be from
deforestation or cc, soil washed away- harder for plants to grow.
Climate change – expecting a 2-3 degrees increase by 2050, there will be
a 20-40% loss of rainforest in next 100 years if temps increase by 2
degrees. Positive feedback – less rain less plants less evap less
rain
River regimes – seasonal discharge changes, reducing precipitation means
lower discharge
Soil – exposed soils
Changes in carbon cycle
Deforestation . albedo affect, reduced ps
Slash and burn – deforestation impacts, rapid return of carbon to
atmosphere. Farmers originally used the ash as a fertiliser but the area
quickly loses fertility.
