Tropical Ranforests Flashcards
Where are tropical rainforests typically found?
Ina broad belt from Central and South America, through central parts of Africa, South-East Asia an into the Northern part of Australia.
What are the main characteristics of a tropical rainforest?
- annual rainfall is 2000+mm
- 27*C throughout the year (both ideal conditions for plant growth)
- rich biodiversity of plant and animal species
- emit 28% of world’s oxygen
- plants form distinct layers - some trees reaching 45m in height
- home to 200 million people
Why do the level of rainfall of rainforests reach over 2000mm yearly?
Because of the high humidity and unstable weather conditions associated with the tropics.
How does the rain in rainforests usually fall?
In torrential downpours on most days
What happens as the precipitation falls?
25% evaporates.
The dense forest canopy intercepts up to 75% of the rainfall:
About half is used by plants then returned to the atmosphere as evapotranspiration. The other half infiltrate into the soil - stored temporarily on the ground surface or flowing overland to river channels (ie runoff).
Some drips down to the ground from leaves or flows down the tree trunks as stemflow.
How is rainwater transferred to the forest floor?
By a combination of drop flow and stem flow. Drip-tips help the tree to shed water from each leaf, and the rest trickles down branches and stems.
Half of the world’s rainforests have already been wiped out to…
Make room for commercial farming, logging, mining and settlements.
Deforestation in the rainforest leads to…
- atmosphere becomes less humid as evapotranspiration is reduced
- with few trees,
