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Rainforests now cover less than 7% of Earths land surface but they are hometo over 50% of all known species of living organisms. And some researchersthink our current number of known species may vastly underestimate Earthstrue total, and that millions more may existespecially in tropicalrainforestswaiting to be discovered. 300 square miles of forest betweenPanama and Costa Rica were found to be home to 500 species of birds, 4 timesthe number living in the broad-leafed forests of all of North America. Onetree in the Amazon may contain more species of ants than found in the entireUnited Kingdom.
But for all this wealth of organisms, theres a constant struggle for scarceresources. Plants fight for raw materials, and life finds ingenious ways totake advantage of every niche and every scrap of energy. Beneath the vastspreading canopy there are, in fact, many very different worlds.