Tropical Rainforests

Characteristic features

Vegetation adaptations to climate

Soils

Location of tropical rainforests

Task – describe the location of the rainforests

Thick waxy drip tip leaves which water runs off

Buttress roots to support tall trees

Grow tall to reach the sunlight

Hot – high solar intensity, monthly average above 27º

Rainfall is high above 2000mm per year

Climate & vegetation adaptations

Immense number

of plants

Shallow roots run sideways below the ground surface

Humid

5. Herb layer with ferns 6m or more high

1. Discontinuous canopy of tree crowns of the tallest trees called emergents

2. Continuous layer of the main canopy formed by the crown of many tall trees

5 distinct layers in the rainforest

3. Discontinuous under canopy of trees between 10m & 20m high

4. Layer of shrubs & young trees

Dominant process is leaching

Rainfall moves through the soil washing down soluble minerals which collect at lower levels

Soil over time loses its fertility

Thin humus layer

Deforestation

• Logging for export to MEDCs – trees should be replanted so the industry can keep selling long term

• Population is increasing – settlement & road building is needed

• Forest cleared to set up cattle ranches which quickly make the soil useless

• Mineral extraction helps Brazil pay foreign debts• HEP development has meant large areas of land

have been flooded

1) By cutting down trees, the world loses 1/3 of its oxygen supply, and ¼ of its fresh water supply, which is stored in the Amazon Basin.

2) Less trees = less water vapour (through transpiration) = less rain = rainforests start to turn into deserts = the species either learn to adapt or die out trying.

3) Burning trees also = releasing excess CO2 = the greenhouse effects = global warming = adverse climate changes worldwide.