🌍 elss sg3 Flashcards
SG3!!! location of amazon rainforest
south america, 70% in brazil
average annual temp in amazon
27.7 c
average annual rainfall in amazon
2000mm
describe seasons in amazon
summer: drier
winter/spring: wetter
similar temps all year round however slightly warmer in summer
vegetation in amazon
- over 50% of worlds plant and animal species
- 300 billion trees
- 15000 species
- 20% of worlds oxygen produced
soil characteristics in amazon
- deep due to chemical weathering of bedrock
- low concentration of nutrients
- top of soil is high in nutrients but this is washed away by rain
significance of amazon in water cycle
river carries 20% of water discharged into earths oceans
significance of amazon in carbon cycle
- NPP of 2500 g/m squared per year
- in 1980s absorbed 2.4 billion tonnes of carbon per year
inputs of water into amazon
- intense sunlight so sun heats oceans and lots of water evaporates
- hot air and water vapour rises
- clouds form over ocean (condensation)
- clouds blow towards amazon
- rainfall over amazon
explain evapotransporation (ET) positive feedback loop in amazon
- heavy rainfall
- dense canopy intercepts lots of rainfall, some is lost by transpiration (25% of all evaporation
- some rain reaches ground
- water taken up by roots from soil
- water lost through transpiration from leaves
- high ET leads to clouds forming
is the amazon a carbon sink or source
carbon sink bc takes in more carbon than absorbs
where is most carbon stored in amazon
below ground in soil and organic matter - 226 tonnes per hectare
describe flows of carbon in amazon
photosynthesis: lots of carbon absorbed bc lots of plants (30 tonnes per hectare)
respiration: lots of carbon released bc lots of plants and animals (25 tonnes released per hectare)
decomposition: lots of organic matter eg leaf litter
describe stores of carbon in amazon
atmosphere: little in atmosphere due to lots of photosynthesis
soil: very deep so stores lots of carbon, lots of decomposition
vegetation: lots of plants due to climate so lots of carbon stored in it due to photosynthesis
describe flows of water in amazon
precipitation: heavy bc lots of ET
evapotranspiration (ET): lots of it because of climate recycles 50% of all rainfall
run off: high in steep areas (andes) & due to saturated soil
describe stores of water in amazon
atmosphere: lots stored due to high ET rates
soil and ground water: high due to deep soil
vegetation: high because lots of plants
ahow much of amazon has been deforested since 1970?
20%
what are the 4 main causes for deforestation in amazon
cattle ranching (65%)
small scale agriculture (17%)
large scale agriculture (7%)
logging (3%)
what are the 3 strategies for managing deforestation in the amazon?
legalisation - amazon regional protected areas (ARPA)
protection & carbon trading - Surui people and un-redd
agroforestry - CREES foundation
summarise the legalisation strategy (ARPA)
- aims to protect 15% of amazon
- largest TRF conservation programme in history (21 years)
- 37% decrease in deforestation
- avoids 1.4 billion tonnes of co2 emissions
- however it doesn’t stop illegal activities from happening eg logging
summarise the protection and carbon trading strategy (Surui people & un-redd)
- indigenous people could sell carbon credits to large businesses
- financed 6 sustainable community developments to generate income
- however the credits kind of gave big companies a ‘guilt free pass’ to carry on polluting
- some of tribe members didn’t like money going to big businesses so teamed up with loggers
- project was suspended in 2016
summarise agroforestry stratergy (CREES foundation
- growing crops while keeping some trees
- 30,000 trees planted
- protects soil in long term
- smaller scale than other projects
how does clearing trees affect the carbon cycle
- less photosynthesis
- more carbon released bc of burning, soil erosion etc
- more carbon in atmosphere, less in biomass
how does converting forest to grassland affect the carbon cycle
- less photosynthesis but still a little bit
- less decomposition so less carbon stored underground
- means more carbon has to be stored in atmosphere = global warming
how significant are the changes to the carbon cycle in the amazon due to deforestation
global: if amazon becomes carbon source, lots more carbon in atmosphere = enhanced greenhouse effect = global warming
is the impact of deforestation long term or short term in the amazon
long term: tipping point could be reached (when amazon loses the ability to renew itself & permanently becomes a carbon source)
how does deforestation increase flood risk in amazon
no trees to intercept rainfall so more to soil, soil is saturated, more surface run off into rivers so flood risk is increased
named flood event:
madeira river basin
- south west of amazon, april 2014
- slopes were clear due to deforestation so water flowed quickly
- 60 people died
- 68000 families displaced
how can deforestation lead to drought in the long term
- deforestation
- less tree coverage to shade grounds so higher air temps
- more water evaporates from soil
- soil becomes drier
- less vegetation supported
- less evaporation
- less condensation
- less rainfall
how significant is the impact to the water cycle in the amazon due to deforestation
local: mostly just local floods due to increased surface run off
is the impact of deforestation short term or long term on the water cycle
long term: could destroy soil and make it infertile so vegetation may not be able to grow back
is the impact of the drought local, regional or global?
local/regional: air has less water vapour so dry air pushed towards andes by winds where it would rise and rain; as there’s less water vapour there would be less rain
are the impacts of the droughts long or short term
long term: if 20-25% of TRF is cut down it could reach a tipping point (would change to a savannah like ecosystem)
