What is hot, wet and sticky?
On this webpage you will find information on the following:
- the climate of the tropical rainforest
- what the soil is like
- the stratification of the vegetation
The soil and climate
A rainforest soil is called a latosol
The climate of the tropical rainforest
The average daily temperature is about 28 degrees. It never goes below 20 degrees and rarely above 35 degrees
At least 2000mm of rain falls a year
The atmosphere is sticky - it's hot and humid
There are no real seasons.
Each day's weather is the same starting off hot and dry, with thunderstorms and heavy rain in the early evening
Soils
Soils are red in colour and rich in iron
They have a thick layer of litter (dead leaves, etc), but only a thin fertile layer - because the leaves rot quickly in the humid conditions
The soils in tropical rainforest are not very fertile, and not particularly good for plants to grow in nutrients are quickly washed or leached out of the soil because of heavy rainfall
Noises and sounds of the tropical rainforest -
http://www.bbc.co.uk/learningzone/clips/images-of-a-tropical-rainforest-biome/3205.html
The average daily temperature is about 28 degrees. It never goes below 20 degrees and rarely above 35 degrees
At least 2000mm of rain falls a year
The atmosphere is sticky - it's hot and humid
There are no real seasons.
Each day's weather is the same starting off hot and dry, with thunderstorms and heavy rain in the early evening
Soils
Soils are red in colour and rich in iron
They have a thick layer of litter (dead leaves, etc), but only a thin fertile layer - because the leaves rot quickly in the humid conditions
The soils in tropical rainforest are not very fertile, and not particularly good for plants to grow in nutrients are quickly washed or leached out of the soil because of heavy rainfall
Noises and sounds of the tropical rainforest -
http://www.bbc.co.uk/learningzone/clips/images-of-a-tropical-rainforest-biome/3205.html
The stratification (layers) of the rainforest vegetation
The vegetation is rainforests grows in distinct layers (see the diagram below), and has adapted to the climate and poor soils
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Plant adaptations to climate
The tropical rainforest's biodiversity is a response to climate. There are constant high temperatures, with a mean monthly average above 27 degrees Celsius, accompanied by high solar light intensity. Rainfall is regular and high, with above 2000mm falling during the year, which creates humid conditions. Plant communities are fiercely competitive. There is survival of the tallest as the tall trees are drawn upwards by the heat and light, which is why leaf growth is concentrated in the canopy. The leathery upper surfaces of
the trees' leaves are necessary to withstand the great power of the sun's rays. The drip tips help the leaves to shed water during the heavy rains. In the lower layers of the forest, sunlight is in short supply. Ferns are adapted to life on the forest floor by having leaves which intercept a high proportion of the light that reaches there. The shrub layer is sparse because a lack of light, although shrubs quickly take advantage of any gap in the forest canopy.
More plant adaptations:
the trees' leaves are necessary to withstand the great power of the sun's rays. The drip tips help the leaves to shed water during the heavy rains. In the lower layers of the forest, sunlight is in short supply. Ferns are adapted to life on the forest floor by having leaves which intercept a high proportion of the light that reaches there. The shrub layer is sparse because a lack of light, although shrubs quickly take advantage of any gap in the forest canopy.
More plant adaptations:
- trees are branchless and the trunks are tall and thin - this helps them to reach the light from the sun more easily
- trees are evergreen - this helps them take advantage of the continuous growing season. The can shed their leaves at any time of year
- leaves often have drip tips - this helps them to shed the heavy rain, and also helps protect them from hungry insects
- some trees have large buttress roots - these support them in the shallow soil. Others spread their roots over the surface - this helps them capture as many of the available nutrients as possible
- lianas are woody climbing vines which drape the rainforest. They climb high into the canopy to reach the sunlight, dropping their roots down to the ground
- epiphytes are plants that grow in the branches of trees - they use the tree for support, not for food
