Layers of the Rain Forest

Layers of the Rain Forest
A rain forest grows in layer. From top to bottom, the four main layers of a rain forest are the emergent layer, the canopy, the understory and the forest floor.

The emergent layer is the highest and consist of very tall tress that emerge, or rise, high above most of the other treetops.

Their branches stretch more than 100 feet (30 m) wide.

The canopy lies below the emergent trees. The upper canopy may be 100 to 130 feet(30 to 40 m) above the ground.

The lower canopy is 75 to 100 feet (23 to 30 m) high. The canopy forms a dense ceiling of leaves and tangled tree branches.

It contains more than 70 percent of a rain forest’s plant and animal life.

Epiphytes cover may canopy trees. Epiphyte are plants that live in other plants. They get food and water from air and rain. Epiphytes help the trees they live on.

When they die and decay, their host plants absorb their nutrients.
Layers of the Rain Forest

Biological Diversity in the Amazon basin

The Amazon rainforest is considered to be one of the most complex and species-rich ecosystems on Earth.

The remarks above show that some of the complexity and diversity results from the locational diversity.

This biodiversity has developed on mostly nutrient-poor and acidic soil, upon which humus layers developed as a refuge for decomposers.

Very high ecosystem productivity is achieved by the formation of almost self-contained, internal nutrient cycles, internal a large number of organisms.

This depends on the maintenance of the geochemical cycles. Disruption to these cycles can have catastrophic consequences that can only be balanced out over extremely long periods.

For a long time it was assumed that this diversity was the result of a process of adaptation that had been going on for millions of years.

However this, idea has been revised in recent years, because the climate was not constant and there were repeated local or regional disasters.

For example, during the Ice Age the climate was colder in the Tropics as well; occasional fire and floods led to temporary, locally limited destruction of the forests.

However, these phenomena did not destroy the flora and fauna, as the Ice Ages did in Europe or North America; through the destruction they led to an increase in biodiversity.

The entire system is by no means uniform. Differences in the soil precipitation, floods and geochemical inputs, linked to differing dry periods, caused evolution that varied greatly from place to place.

All of this means that the Amazon basin is a colorful mosaic of the most varied ecotopes with living communities in a varying stage of succession, but which has hardly been researched to date in terms of its multifaceted strictures and functions.
Biological Diversity in the Amazon basin