Rainforests

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What is a Rainforest?

A rainforest is a forest near the equator that is warm all year. Rainforests currently cover less than 6% of the Earth’s surface, yet they produce 40% of the Earth’s oxygen. Many rainforest trees are very tall. Over 254 centimeters (100 inches) of rain falls in a rainforest per year. Rainforests are very moist all of the time. In fact, the average humidity is between 77% and 88%.

Climate

Layers

Emergent Layer

This layer is made up of a few exceptionally large trees which surpass the height of the canopy layer. These trees are generally 45-55 meters tall, although some occasionally grow to heights of 60 and even 70 meters. This layer is home to eagles, butterflies, bats, and some species of monkeys.

Canopy Layer

The canopy is the most diverse of all the rainforest layers. Out of the over 50% of the world’s species of plants and animals that can be found in rainforests, at least 40% can be found in this layer. The trees found in the canopy layer are 30-45 meters tall. Scientists have only recently discovered ways of exploring the rainforest canopy. The science of exploring a tropical rainforest canopy is called dendronautics.

Understorey Layer

This layer is inhabited by a variety of birds, snakes, and lizards, as well as predators such as leopards, jaguars, and boa constrictors. There are a lot of insects in this layer. Many trees at the understorey level will eventually grow up to the canopy layer. Since very little sunlight penetrates all the way to this layer, only about 5%, the leaves of the plants in the understorey are quite large.

Shrub Layer

The shrub layer is just above the forest floor. The leaves in this layer are very big. This layer is far less diverse than the upper layers which receive more sunlight.

Forest Floor

Receiving only a measly 2% of the sunlight of the, plants and animals must be well-adapted to live in this layer. The forest floor holds decaying matter from plants and animals, and there are a wide variety of fungi which speed up the decaying process.

Biota

More than half of the world’s plants and animals can be found in rainforests. That is to say, over 5 million species. The tropical rainforest ecosystem is the most biodiverse in the world.

Fauna

The animals that can be found in a tropical include mammals (primates, felids, other families), reptiles (snakes, lizards, chameleons, other families), birds, and invertebrates.

Flora

Soil

Tropical Rainforest Soil

The soil of a tropical rainforest is, surprisingly, low in nutrients and quite poor. It is ancient and also very delicate; if the soil of a tropical rainforest is damaged, it can take many years to recover. This soil is only about 8-10 centimeters (3-4 inches) thick. Underneath the soil is solid clay.

Temperate Rainforest Soil

Temperate rainforests have soil that is much richer in nutrients than the soil of tropical rainforests. It is not very old, and is also much less prone to damage.

Rainforest Destruction

Logging is the main threat to rainforests. Studies show that every minute, about 2000 trees are cut down. Every five to forty-five minutes, a species is extinct, due to rainforest logging.

Extreme Weather–What Does it Do?

Rain Patterns

Tropical rainforests have very consistent rain patterns, because there are specific time where it should or should not rain for the good of the ecosystem. These important rain patterns are synchronized with all other events; the birth of animals and insects, the seasons, seed releasing of plants, and basically all else that goes on in a rainforest. In short, consistent rain patterns are vital to the rainforest ecosystem. So what happens when it rains when it shouldn’t, and does not when it should? This, caused by warmer overall world climate, upsets the timing of flowering and fruiting, which needs to be the same few days that most of the animals and insects are born in, or when flocks of migratory birds and bats pass through. Without perfect timing, mass starvation of the new generation, migratory birds, and to a lesser extent all the other animals occurs.

Droughts

Droughts are another significant threat to tropical rainforest. Droughts often result in the loss of large trees, as they dry out and die. They then become unstable, grow fungi, decompose, and generally can no longer support rainforest life in any form then that dirt (or perhaps nurse logs, for a limited amount of time). Each of these trees are likely to formerly have been home to thousands of creatures (the majority of which are insects) and many of those thousand will accordingly be rendered homeless and often lacking their staple food source as the tree dies. Droughts also cause lack of food due to offset of blooming and fruit production schedule.