The beauty, majesty, and timelessness of a primary rainforest are indescribable. It is impossible to capture on film, to describe in words, or to explain to those who have never had the awe-inspiring experience of standing in the heart of a primary rainforest. Rainforests have evolved over millions of years to turn into the incredibly complex environments they are today. Rainforests represent a store of living and breathing renewable natural resources that for eons, by virtue of their richness in both animal and plant species, have contributed a wealth of resources for the survival and well-being of humankind. These resources have included basic food supplies, clothing, shelter, fuel, spices, industrial raw materials, and medicine for all those who have lived in the majesty of the forest. However, the inner dynamics of a tropical rainforest is an intricate and fragile system. Everything is so interdependent that upsetting one part can lead to unknown damage or even destruction of the whole. Sadly, it has taken only a century of human intervention to destroy what nature designed to last forever.
Why should the loss of tropical forests be of any concern to us in light of our own poor management of natural resources? The loss of tropical rainforests has a profound and devastating impact on the world because rainforests are so biologically diverse, more so than other ecosystems (e.g., temperate forests) on Earth. Consider these facts:
If Amazonia were a country, it would be the ninth largest in the world. The Amazon rainforest, the world's greatest remaining natural resource, is the most powerful and bioactively diverse natural phenomenon on the planet. It has been described as the "lungs of our planet" because it provides the essential service of continuously recycling carbon dioxide into oxygen. It is estimated that more than 20 percent of Earth's oxygen is produced in this area. The Amazon covers more than 1.2 billion acres, representing two-fifths of the enormous South American continent, and is found in nine South American countries: Brazil, Colombia, Peru, Venezuela, Ecuador, Bolivia, Guyana, French Guiana, and Suriname. With 2.5 million square miles of rainforest, the Amazon rainforest represents 54 percent of the total rainforests left on Earth.
from The Healing Power of Rainforest Herbs by Leslie Taylor