The Importance of Forests

Forests as Earth's air purifiers

Just as our lungs absorb carbon dioxide from the blood and infuse it with oxygen, green plants absorb carbon dioxide during photosynthesis and release oxygen into the atmosphere in return. Which is why forests are often referred to as the Earth's lungs. This epithet is most widely used with regard to the Amazon rainforests, the world's largest surviving tropical forest.

Carbon guzzlers
We all know about photosynthesis - the production of energy in the presence of light by chlorophyll - containing plant parts for the subsistence of the organism. Carbon dioxide, the major greenhouse gas, is a major requirement of photosynthesis.

This suits us just fine as it means forests form an effective sink for the carbon dioxide produced as a result of animal respiration, burning of fossil fuels, volcanoes and other natural and human-induced phenomenon. And if that is not all, a by-product of photosynthesis is oxygen. Thus, the Amazon forests are the Earth's air purifiers, given the large amounts of carbon dioxide they absorb from the atmosphere.

Going, going...
However, these South American rainforests - all forests, really - are being depleted at alarming rates. The lungs of the planet are increasingly being likened to those of a compulsive smoker. Scientists, including the FAO, estimate that more than 50 per cent of the original rainforest cover has been lost since the beginning of the twentieth century, and what remains is disappearing at an alarming rate.

Many of these forests have existed for millions of years, and over a third of the world's plant and animal species live here. In some areas more than 200 tree species have been known to exist on a single hectare of land!

Logging and accidental fires: Not so innocent
Deforestation had been the major culprit in the disappearing forest cover. However, in a study published in Nature in late 2004, researchers say that the forest is disappearing faster than we think, as logging and accidental fires - which were assumed to have minimal impact - are not taken into account in standard calculations.

In the Amazon, they said, logging practices and wild fires destroy as much or perhaps more annually than deforestation, and this affects more communities than earlier estimated. In fact, humans may be eliminating the Amazon rainforests at twice the rate we earlier thought.