The competition is intense and responsible for thousands of different chemicals found in tropical forest plants. Around 25% of all drugs found in a modern pharmacy, in fact, are derived or copied from those found in the rainforest. The reason of this is quite simple.
Unlike animals, plants are unable to run away from predators. Instead over millions of years they have evolved a bewildering variety of what are called “secondary compounds” chemicals that have nothing to do with the plant physiology but rather have evolved solely for defensive purposes.
A single hectare (2.5 acres) of rainforest can hold up to nearly 300 different species of trees (a typical temperate forest may have 20) in reality the jungle represents the largest, most highly-sophisticated repository of biologically - active chemicals in the world.
On Manu’s floodplain the vegetation is therefore especially rich; in fact visitors will see some of the Amazon’s only remaining natural stands of tropical cedar (Cedrela odorata) as well as scattered mahogany trees (Swietenia macrophylla). Both are economically important hardwoods that have been logged nearly to extinction.
A tree specie made part of the Manu history is the local Rubber Tree (Hevea brasiliensis) which was regularly and continual cut to supply of latex or rubber gum.
