AMAZON RAINFOREST Flashcards
size of amazon
worlds largest tropical rainforest
covers 40% of SAm land mas
covers 68% of brazil
conditions of amazon
very hot and wet
vegetation is very dense
what lives there
many indigenous people
1 million plant species
500 species of mammals
2000 species of fish
- particularly endangered species of them all
what causes the amazon to be so wet
evaporation from the Atlantic ocean being blown over
what causes high evapotranspiration
warm temperatures
what causes high interception rates. what’s does this mean for the water cycle
dense canopy
less water flows - flows more slowly into the river
what are the species adapted towards
the high humidity
what dos the amazon store, what does this make it
carbon - in vegetation and soil
carbon sink
how much of the amazon is considered a carbon source
1/5
negative feedback loop - CO2 and plants
increase CO2
increased productivity - plants absorb more CO2 for photosynthesis
biomass increases
how much CO2 absorbed in 1990s vs 2015
1990 - 2 billion tonnes
2015 - 1 billion tonnes
how much of the original land has been lost to deforestation
17%
what % of deforestation is associated with farming
90% - cattle and agriculture
- arable and pastoral
what impact does deforestation - farming have on the water cycle
no tree canopy to intercept rainfall - more water reaches ground surface
fills up water table
becomes runoff
increase flood risk
decreased river discharge
what does deforestation do to evapotranspiration.
what does this mean - neg
reduces it
less water in the atmosphere, fewer clouds and rainfall is reduced. 1/3 of the areas rainfall is recycled - could lead to drought
what does reduced evapotranspiration mean after deforestation.
- change weather patterns locally
- affects carbon cycle
what does reduced evapotranspiration mean after deforestation - change weather patterns locally
become wetter/windier at local scale
cleared areas warm up faster and warm air rises, creating low pressure - drawing in moist air from surroundings
vegetation breezes create clouds and rain
what does reduced evapotranspiration mean after deforestation - affects carbon cycle
w/o roots to hold soil, heavy rain washes away top layer of soil
= transfers carbon from soil –> hydrosphere
human activities that affect carbon and water cycles
deforestation
climate change
what does fewer trees mean
less photosynthesis
less CO2 taken up
global warming increased
how many tonnes of carbon per hectare do tropical rainforests hold
500
how many tonnes of carbon per hectare does farmland hold
5 tonnes
100 times less than tropical rainforests
more CO2 left in the atmosphere
what has drought been experienced
what years has this happened
temp increasing
rainfall decreasing
2005, 2010, 2015-16
what does drought encourage
forest fires
- releases more carbon into atmosphere, increased GHE
what do scientists predict
4*C temp rise = kill off 85% of amazon - increase CO2 emissions
- more decomp
- less photosynthesis
how much less carbon does secondary forests store
regrowth of secondary forest = 40% less carbon than original forest
what can be done to limit human impact
selective logging
replanting
environmental law
protection
selective logging
only some trees (usually oldest) are felled
less damaging to the forest - not all trees are cut down
- canopy is still there
- soil is still held together
- photosynthesis continues at a similar rate
replanting
new trees are planted - replace the ones cut down
replanting initiative in PERU
replanted 115 acres of forest - 2016-2019
same trees must be replanted to maintain balance i the water and carbon cycles
environmental law
laws that ban the use of wood from the forest that are not managed sustainably
ban excessive logging
control land use to protect rainforests
what environmental law has been put in place in brazil
Brazilian Forest Code
brazilian forest code
landowners have to keep 50-80% of their land as forest
protection
many countries set up national parks and nature reserves - protect rainforests
damaging activities - logging - can be monitored and prevented
what did brazil set up - protection
Central Amazon Conservation Complex
Central Amazon Conservation Complex
2003
covers 49,000km3
