Rainforests

A rainforest is a biome ( an area with similar climate).

Climate - based on temperature and amount of rainfall

Most rainforests are in South America.

Rainforests:

1.) Are very hot and humid.

2.) Are located mostly in the tropics, where the sun is higher in the sky.

3.) Have a large energy supply due to receiving 12 hours of direct sunlight each day.

Rainforest soil is not very fertile. All of the nutrients are used up quickly because there are so many plants competing for them.

The nutrients in the soil are used almost as soon as they are replaced. Even decomposition occurs faster because the area is so wet.

Because of this, rainforest soil makes suprisingly poor farmland.

Trees and other plants must adapt to living in the rainforest.

How do they do this?

1.) Trees have shallow roots as most nutrients are in the topof the soil.

2.) Many trees have broad leaves. Why?

3.) Some plants have developed ways of destroying theirCompetition, such as having acidic roots or strangling them.

There are several levels of growth in the rainforest.

Rainforest Layers:

Emergents - trees that rise above the canopy

Canopy - the tops of the trees; gets the most light; food is plentiful

Understory - plants must be shade-tolerant; several layers within theunderstory

Herb and Shrub Layer - forest floor; few plants and little light

Biodiversity - great variety of life

There is biodiversity in the rainforest because:

1. Large amount of rain

2. Warm temperatures

3. Large amount of sunlight

In fact, so many plants and animals live in the rainforest, it is estimated that less than 10% of all organisms living there have been identified.

Some rainforest vocabulary:

Biosphere - all living things and their environments

Arboreal - tree-dwelling

Habitat - place where an animal lives

Camouflage - pattern or color that helps an animal survive by blending in to its surroundings

Deforestation - the removal of large amounts of trees; a concernin the rainforest today

How does this affect us?