Types of Rainforests
More than 40 different kinds of rainforest have been categorized by experts. Some differentiate mainly by amount of rainfall. Others emphasize soil or altitude as the defining features, or use a combination of all these. Most agree we can think of 4 main types of forest:
Here rainfall and humidity are relatively constant throughout the year, though dry and wet seasons do occur. The "terra firme" (dry land) rainforest seen around Manaus and featured in LFRF is typical of such forest.
Flooded forests are of two kinds, in Portuguese "varzea" and "igapo." "Varzea" is forest flooded for a short time after heavy rains, which sometimes raise the water level by as much as 10 meters (33 feet.) "Igapo" refers to that far stranger forest which may be under as much as 40 feet of water for up to 11 months of the year! This unusual phenomenon has resulted in bizarre adaptations both of trees and fish: trees take on strange shapes and strategies to survive in conditions that would kill most temperate species, and fish swim between submerged branches and have come to live on fruit and seeds.
Montane (or "high land") rainforest includes the cloud forests of Costa Rica and Puerto Rico, where plants drink moisture from the misty air as much as from rain and roots.
Mangroves, with their distinctive stilt roots spreading out into the water, are found on coasts and river banks around the world, from Florida to Vietnam. Like wetlands, they serve as filters for the waters that flow through them, and like wetlands everywhere, are subject to pressures from population, agriculture and industry.