Tropical Rainforests Flashcards
Tropical rainforest are important because
Home to 200 million people
Estimated to contain half the world’s plant and animal species
Huge biodiversity
Absorb huge quantities of CO2 and emit 28% of the world’s oxygen
Tropical rainforest water cycle
2000mm of precipitation
75% of rainfall intercepted
50% used by plants
50% infiltrates into the soil
What is the ITCZ
The ITCZ is the point where the 2 Hadley cells meet at the equator.
Here air pressure is low (rising air) and evapotranspiration happens in huge amounts causing lots of rain, this in turn leads to the rich vegetation and biodiversity of the tropical rainforest
Amazon rainforest and the drivers of change
The amazon rainforest has lost approximately 17% of its primary rainforest in the last 50 years
80% is due to cattle ranching. Other reasons include logging mining and for housing
It is most apparent in the east and south east parts of Brazil and in the North Western arc in Colombia and Ecuador.
Between 2000 and 2007, 19,386km² was being g destroyed per year
Impacts of change on the water cycle?
Evapotranspiration
- As Evapotranspiration is reduced the atmosphere becomes less humid
- Transpiration will rapidly decrease
- With less trees, most rainfall will go straight to the floor encouraging surface flow as soils become dry and baked as it becomes more exposed to the sun
Rainfall
Particles resulting from burning of trees increases the density of airborne aerosols around which water vapour condense. As a result, smaller droplets occur in the clouds which are too small to precipitate resulting in less rainfall.
Mitigation
ACTO (amazon cooperation treaty organization)
Aimed at promoting sustainable development
8 member countries
Reverse the loss of forest cover worldwide through sustainable forest management, including protection, restoration, afforestation and increase efforts to prevent forest degradation
