The rainforests of the world cover less than 6 % of the earth’s surface
The Hindu: 17 September 2013
September 16, 2013
The world’s rainforests are home to half of all the planet’s living animal and plant species. And, yet these biodiversity hotspots cover only six per cent of the earth’s surface. What is truly amazing, however, is that these forests still hidemillions of undiscovered plants, small animals, insects and microorganisms inside them.
Dense jungles with a thick cloud cover that keeps the forest wet, warm and humid all year round, and tall trees reaching for the sky while plants down below grow close together – the rainforest is a magical place. But what makes these amazing forests an indispensable resource to mankind? Inside, the rainforest is a hub of activity with life-supporting systems that makes it a biodiversity hotspot. Also, the unique geographical locations of these rainforests truly make it one-of-a-kind.
Tropical and temperate rainforests
The world’s rainforests are divided into two types: tropical and temperate. Tropical rainforests are found between the Tropics of Cancer and Capricorn. Hot and mostly moist, these include the Amazon in South America, Congo rainforest in Central Africa and even the Western Ghats in India. In South Asia, tropical rainforests stretch from India and Burma in the west to Malaysia and the islands of Java and Borneo in the East.
Temperate rainforests, on the other hand, are found along some coasts in temperate zones. The largest temperate rainforests are found on the Pacific coast of North America. Smaller temperate rainforests can be found on the south east coast of Chile in South America, as well as in smaller areas in UK, Norway, Japan, New Zealand and southern Australia.
Lungs of the planet
The rainforests of the world are essential to the survival of man on this planet. They have been called as the lungs of the planet for the role they play in absorbing carbon dioxide and producing oxygen. Rainforests act as huge carbon sinks, taking in a major portion of carbon dioxide, a greenhouse gas, and storing it in their roots, stems, leaves and branches. As a result rainforests help stabilize the earth’s climate and even fight pollution.
The rainforest is nearly self-watering. The plants in this delicate ecosystem release water into the atmosphere through a process called transpiration. In tropical rainforests, the canopy trees – the largest trees of the rainforest – release about 760 litres of water each year. Consequently, rainforests play a vital role in regulating rainfall and keeping the water balance. Destruction of the rainforest will lead to an increase in global warming and affect the climate of the world.
Rainforests are the Earth’s oldest living ecosystem. Today, they contain the most concentrated areas of biodiversity. More than two-thirds of the world’s plant species live in tropical rainforests.An area of the rainforest the size of two football fields may have more than 400 species of trees. What makes tropical rainforests such hotspots for biodiversity? The canopy structure of the forest provides an abundance of places for plants to grow and animals to live. The canopy offers sources of food, shelter, hiding places and interaction between different species for the plants and animals to thrive. Moreover, tropical rainforests receive a lot of sunlight because of their geographical location. The process of photosynthesis helps plants convert the sunlight into energy that supports life in the rainforest. A number of unique plant and animal species will become extinct if the rainforests are destroyed.
Also, did you know tropical rainforests thrive with medicinal properties? Less than 1 per cent of the world’s tropical plants have been tested for pharmaceutical properties, yet at least 25 per cent of all modern drugs came originally from rainforests. The plants of the rainforest are used in medicines that fight illnesses like cancer, leukaemia and heart disease. Since the plants in the rainforest grow very close together and have to deal with the constant threat of insect predators, they’ve adapted by producing chemicals that researchers have found useful as medicines. It is estimated that 70 per cent of the anti0cancer plants identified so far are present only in rainforests. Many plants and trees, like orchids, have been removed from the rainforest in an effort to cultivate them. However, some like the Brazil nut tree of the Amazon refuse to grown anywhere but in their homes.