Rainforest is a type of forest depicted by high rainfall with yearly rainfall between 250 and 450 centimeters that is about 98 and 177 inches. There are two known types of rainforest namely temperate rainforest and tropical rainforest. Monsoon though, otherwise known as Intertropical Convergence Zone, plays a vital role in establishing climatic conditions that are necessary for the tropical rainforest of the Earth.
About 40% to 75% of biotic species are considered as indigenous to rainforests. There are approximately millions of species of insects, microorganisms and plants that remain undiscovered in these tropical rainforest. This type of rainforest are referred to as “Jewels of the Earth” and is recognized as the largest pharmacy of the world. This is because tropical rainforest has more than one quarter of natural herbs and medicines discovered there.
Rainforests are said to be responsible for about 28% of oxygen turnover of the world and at times, misnamed production of oxygen processing this through photosynthesis and consuming this via respiration. Undergrowth on certain areas of the rainforest can be controlled through poor sunlight penetration to a ground level. In case leaf canopy is thinned or destroyed, the ground underneath will soon be colonized by small trees, dense and tangled growth of shrubs and vines.
Two Types of Rainforest
There are two types of rainforest and each type has its own sets of features and descriptions. The two types of rainforest are discussed below:
Tropical rainforest is characterized by wet and warm climate. Indicated monthly temperature often exceeds 64 °F or 18 °C during the entire months of the year. The average rainfall annually is not less than 66 inches or 168 centimeters and can exceed 390 inches or 1,000 centimeters. Majority of rainforest in the world are linked with the monsoon trough location, which is also referred to as the Intertropical Convergence Zone. Tropical rainforest are usually nestled in tropics or equatorial zone. Tropical rainforest has been referred to as “Earth’s lungs” however it is presently known that rainforest gives minimal oxygen addition in the atmosphere via photosynthesis.
Tropical rainforest typically covers larger part of the world however, temperate rainforest occurs in fewer regions in the world. Temperate rainforests are types of rainforests that are mostly found in the temperate regions. They can occur in Columbia, Washington, North America, California and Oregon. Temperate rainforests are also found in Europe, East Asia and many more.
Tropical rainforest is commonly divided into four primary layers and each layer with diverse animals and plants adapted in a particular area. These layers include canopy, emergent, understory and the forest floor layer.
This layer contains small numbers of larger trees known as emergents. These trees grow above general canopy reaching the height of 45 to 55 meters although in some cases, some species grow 70 to 80 meters tall. These trees need to withstand strong winds and hot temperatures occurring above canopy in certain areas. Bats, butterflies, monkey and eagles usually inhibit this particular layer.
The canopy layer is composed mainly of largest trees usually 30 to 45 meters tall. The densest biodiversity areas are located in forest canopy more or less continuous foliage cover formed by the adjacent treetops. The canopy is said to be the home of approximately 50% of plant species. The fauna is the same to that seen in emergent layer but this is said to be more diverse. A quarter of the total insect species are believed to live and exist in rainforest canopy.
This particular layer lies in between the forest floor and canopy. This is also the home for considerable numbers of lizards, snakes, birds and predators such as leopards, jaguars and more. The leaves are larger in this level and there is an abundant insect life. Several seedlings that grow in the canopy level are found in this layer. Only 5% of sunlight shining on rainforest canopy is able to reach the understory layer. This is sometimes called as the shrub layer though this can also be known as separate layer.
This is the bottom-most layer receiving only about 2% of sunlight. Plants that adopt to low light can live and grow in this particular region. Away from clearings, riverbanks and swamps where concealed undergrowth is found, forest floor is apparently clear of some sort of vegetation due to low and poor sunlight penetration. This layer also contains decaying animal and plant matter that disappears quickly due to humid and warm conditions promoting rapid decay. Many types of fungi also grow in the forest floor and help in decaying plant and animal waste.
Flora and Fauna
Almost half of the animals and plants species of the world are spotted in rainforest. This supports wide range of fauna including reptiles, mammals, invertebrates and birds. Mammals include felids, primates and all other families. Reptiles may also include turtles, chameleons, snakes and other families while the birds include Cuculidae and Vangidae families. Dozens of invertebrate families are also found in the rainforest. Fungi are common in these areas since they can feed on decomposing remains of animals and plants. However, due to deforestation, pollution and habitat loss, several rainforest species are disappearing rapidly.
Despite vegetation growth in tropical rainforests, the quality of soil is poor. Quick bacterial decay prevents humus accumulation. The aluminum oxides and iron concentration through laterization process gives oxisols a red bright color and sometimes making mineral deposits. Most trees got roots near surface. If the rainforest trees are cleared, the rain accumulates on exposed surface of the soil creating a run-off and starting a soil erosion process. Eventually, rivers and streams form and there is a high possibility of flooding.
Tropical rainforests give timber and animal products like hides and meat. Rainforests also has a significant value in terms of being tourism destinations. Plenty of foods originally came from these types of forests. There are also plant derived medicines found in rainforest used in reducing fever and treating burns, gastrointestinal problems, fungal infections, pain, wounds and many more.