Short answers, pulled from the story.
Emergent trees in the rainforest reach heights of 45 to 55 meters, with some species growing as tall as 70 to 80 meters to withstand the hot temperatures and strong winds that occur above the canopy.
The soil quality in the rainforest is poor because rapid bacterial decay prevents the accumulation of humus, and the concentration of iron and aluminium oxides by the laterization process gives the oxisols a bright red colour. Most trees have roots near the surface because there are insufficient nutrients below the surface, and the high volume of rain washes nutrients out of the soil more quickly than in other climates.
The forest floor of the rainforest receives only 2 percent of the sunlight, which makes it relatively clear of vegetation away from riverbanks, swamps, and clearings. This layer contains decaying plant and animal matter that disappears quickly because the warm, humid conditions promote rapid decay.
On the 18th of January 2007, FUNAI reported that it had confirmed the presence of 67 different uncontacted tribes in Brazil, up from 40 in 2005. This addition allowed Brazil to overtake the island of New Guinea as the country having the largest number of uncontacted tribes.
Estimates vary from 40 percent to 75 percent of all biotic species being indigenous to the rainforests, and there may be many millions of species of plants, insects, and microorganisms still undiscovered in tropical rainforests. Tropical rainforests have been called the world's largest pharmacy because over one quarter of natural medicines have been discovered there.
At present rates, tropical rainforests in Indonesia would be logged out in 10 years and Papua New Guinea in 13 to 16 years. An important reason for the increasing deforestation rate, especially in Indonesia, is the expansion of oil palm plantations to meet growing demand for cheap vegetable fats and biofuels.