Amazonia or Amazon rainforest is the largest tropical forest on the planet.
Shared by nine countries in South America, about 60% of it is located in Brazil, covering nearly 50% of the country.
This gigantic repository of plant and animal life covers an extension of over 2.7 million square miles, providing the drainage basin of the Amazon river and its many tributaries - about 1,100 of them - from the Peruvian Andes (where the Amazon river is born) to the Atlantic ocean.
Primary rainforest is vertically divided in four layers: forest floor, understory, canopy and emergent or overstory.
Of all rainforest layers, the Amazon rainforest canopy is the thickest and wealthiest of them all, home to 50% of all plant species.
Furthermore, according to some estimates, half of all life on Earth could be found there.
As for wildlife, there is a wide diversity of animal species, due to the variety of food sources in the canopy tress: monkeys, amphibians, birds, bats, insects.
Just the number of insect species is estimated to reach up to two million, while about 80% of them are still unknown to science.
In fact, the Amazon rainforest canopy is one of the last biological frontiers of the world, where much of the action in the rainforest occurs.
Just below the top, emergent layer - with trees towering up to 200 feet and trunks that can reach up to 16 feet in diameter, such as the great kapok tree - the rainforest canopy reigns between one and two hundred feet (approx. 30 to 45 meters) above the forest floor.
About 90% of the forest photosynthesis - the process of converting sunlight into energy - takes place at canopy level, with billions of leaves converting atmospheric carbon dioxide and water into oxygen and simple sugars.
The wealth of the rainforest's fruits and flowers is found there.
Filtering out about 80% of the sunlight, the Amazon rainforest canopy shields the understory and forest floor layers from intense sunlight, winds and heavy rainfall, retaining the moisture of the forest below.
It also plays an important role in regulating regional and global climate because it is the principal site of the interchange of heat, water vapor and atmospheric gases.
Epiphytes plants - plants that grow upon another plant non parasitically - and lianas are abundant in the rainforest canopy.
Mosses, orchids, bromeliads, lichens, ferns are epiphytes or air plants, because they do not root in soil.
It's believed that the number of orchid species found in the canopy equals more than twice the number of bird species and about four times the number of mammal species.
As for lianas, there are 90 families known and about 2,500 species of them.
They connect the entire rainforest, providing bridges to arboreal animals and could be as strong as to support the weight of an adult human.
Today, however, the Amazon rainforest canopy puzzle is far from being deciphered, as exploration of this habitat is still in its infancy.
In the last three decades, new ways to studying it have been developed, from crossbows, cranes and walkways to ballons and airships.
Many species, systems, and relationships of the canopy are still mysterious and much is still left to be discovered about the Amazon rainforest ecosystem...