What are Rainforests?
Rainforests are thickly populated, tree dominated areas, with plenty of rainfall. Even though they cover only about 6% of our Earth, rainforests contain much of the world’s biodiversity, including epiphytes, lianas, mammals, birds, and insects as well as some of the Earth’s oldest living ecosystems (we’re talking 70 million years!). Did you know that there are almost no forest fires in rainforests due to the high humidity and constant rain fall?
The Forest Biomes
There are three major forest biomes - temperate, tropical, and boreal (also known as the taiga). These forest types occur at different latitudes, and therefore experience different climatic conditions. The typical rainforest belongs to the tropical biome variety. Called “the jewels of the Earth”, the tropical rainforests are warm, humid, and found close to the equator. Average rainfall is about 66” (168 cm) and can exceed 390” (1,000 cm). Temperate forests are found at higher latitudes and experience all four seasons. Boreal forests are found at even higher latitudes, and have the coldest and driest climate, where precipitation occurs primarily in the form of snow. An exception to the typical tropical rainforests are the cloud forests. They are found at high altitude mountains where they are nearly always immersed in clouds. The climate here is very cold and extremely wet.
Rainforest Layers
There are three layers in any rainforest. At each layer there are animals and plants that have adapted to that domain since millennia.
· Rainforest Floor: This is the bottom-most layer, the ground level. Only about 2% or less sunlight penetrates to this level. It is warm and humid. Hence, ideal for many types of fungi growth like mushrooms. This layer collects all types of plant and animal debris. However, the bacteria are quickly cleaned up by the fungus. This layer is home to anaconda, caiman and countless more species.
· Understory Layer: This forms the middle and most vibrant layer. Obtaining around 5% sunlight, here we can find a large number of animals, birds, reptiles, and insects. All the large and beautiful creatures such as the colorful macaws and the fearsome jaguar live here.
· Canopy Layer: The topmost layer. Mainly containing trees as tall as 98’(30 m) to 148”( 45 m). This layer gets all the direct sunlight and is the least studied layer of all the rainforests.
Why are Rainforests important?
o Oxygen: Scientists say that the world’s rainforests provide about 20% of our oxygen. They absorb as much as 20% or more of carbon dioxide emitted by humans. If they are cut down, then our oxygen supply will dwindle as it is happening now.
o Food: Around 80% of world’s food supply come from rainforests.
o Medicine: Called “the world’s largest pharmacy”, scientists say that about 25% of our medicines are developed from plant materials that come only from the rainforests. Also, since only around 1% of the plant species of rainforests have been studied, it means there may be an extraordinary number of plants that should be studied for more benefit.
o Erosion and Flooding: When it rains, trees and bushes absorb water through their roots and then the water is dispelled through the pores in their leaves in a process called transpiration. This continuous cycle protects the forest floor and helps soil conserve minerals and prevents erosion. Cutting away trees makes the soil lose their nutrients. There would also be uncontrolled flooding.
o Biodiversity: Tropical rainforests harbor about 40%-75% of world’s animal and plant species! Many of them are found nowhere else in the world. It is staggering to think about it. There may be millions of more plants, microorganisms and insects that have yet to be discovered. Also, in rainforests all over the world there are indigenous tribes with their own unique culture. They depend completely on these forests for their sustenance and their very existence.
What are happening to the Rainforests now?
Deforestation is occurring at an astounding rate. Over 90% of Africa’s vast rainforests have been destroyed. This goes for other areas as well. But there is hope! Plans have been put into place to curb deforestation on a large scale in many countries.
If you want to help save the Rainforests, then please visit: Rainforest Trust
Did you know?
(1) Epiphytes are organisms and plants that grow on other plants. Lianas are vines which have their roots in ground. They use forest trees to grow upwards the canopy to obtain sunlight
(2) The world’s largest remaining tropical rainforest is the Amazon which covers Argentina, Peru, Paraguay, and Uruguay. And 60% of the Amazon lies in Brazil. The second largest rainforest is in Central Africa in the Congo Basin in the Democratic Republic of Congo.
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