[sustaining ecosystems] rainforests

Biodiversity

The variety of flora and fauna in a habitat.

Why do certain regions have tropical climates?

• areas of low pressure (warm + wet weather)

• high temperatures = sunlight concentrated at the equator / smallest surface area + sun radiation travels shorter distance (high insolation)

• high precipitation = clouds condensing from warm air rising

Why do certain regions have dry climates?

• areas of high pressure (dry and clear weather)

• high temperatures

1st Level of Rainforests (approx. 50m)

Emergents

2nd Level of Rainforests (approx. 30m)

Canopy

3rd Level of Rainforests (approx. 20m)

Under Canopy

4th Level of Rainforests (approx. 10-0m)

Shrub Layer

1st Stage of Rainforest Water Cycle

Heavy, daily, convectional rain.

2nd Stage of Rainforest Water Cycle

Tall trees intercept rain.

3rd Stage of Rainforest Water Cycle

This leads to only some rain reaching the ground and soil.

4th Stage of Rainforest Water Cycle

Trees take up water.

5th Stage of Rainforest Water Cycle

Water evaporates from surfaces of the trees and leaves of flora in general (transpiration).

Humus

Dark, organic material that forms in soil when plant and animal matter decays.

Leaching

The removal of nutrients by water.

1st Stage of Nutrient Cycle

Trees shed leaves all year round.

2nd Stage of Nutrient Cycle

Decaying vegetation decomposes rapidly.

3rd Stage of Nutrient Cycle

Nutrients from the decay enter the soil.

4th Stage of Nutrient Cycle

Shallow roots take up the nutrients.

5th Stage of Nutrient Cycle

Trees grow rapidly as they have access to these nutrients.

Rainforests' Soil Profile

- the soil is very deep but it only has a thin, fertile layer meaning the rest of the soil lacks nutrients (infertile)
- hot + wet weather means chemical weathering is rapid, usually meaning there is a deep layer of soil