Tropical forests are one of the greatest biodiversity in the world. These regions are located, for the most part, in the zone between the tropics.
Characteristics Tropical Forests:
- Rich biodiversity with a large number of plant and animal species. Many of these species are still unknown to humans.
- They have soils covered with humus (30 to 50 cm), coming from the decomposition of leaves, fruits, feces and carcasses of dead animals.
- Great presence of shade, since the trees are very close to each other. These trees are, on average, 30 to 50 meters high.
- Heat almost all year round, with average annual temperatures of 20º C.
- Frequent and abundant rains (1200 millimeters annually).
- They occupy only 7% of the earth’s surface.
The highest incidence of tropical forests is in the following regions: Africa (Congo river basin and Liberia), Central America, South America (Amazon forest and Atlantic forest), Asia (Vietnam, Laos, Cambodia and Thailand) and regions of Oceania (New Guinea, Borneo and the northern coast of Australia).
Fauna and Flora
Tropical forests are biomes composed of a large number of plant and animal species, concentrating approximately 50% of the life on the planet, even occupying less than 2% of the Earth’s surface.
There are at least 5 billion species still unknown in these forests. The biodiversity is enormous since one hectare of land concentrates up to 480 species of trees.
The number of species results from the peculiarities of the climate, humidity and presence of light and influence on the availability of carbon. Nearly 4,000 meters of tropical forest concentrate more carbon than the same amount of any other vegetation. Between 70% and 90% of forest life is in the trees.
Tropical forests have lush vegetation due to the large amount of solar energy and water they receive, so much so that the vegetation grows throughout the year, with trees reaching up to 60 meters in height.
The leaves of the trees are wide, which facilitates the absorption of sunlight without dehydrating them, since the water that the plant loses during transpiration is compensated by the absorption of water by the roots. Tree roots are shallow.
It is common to find tubular roots that provide greater fixation of the plant.
In tropical forests, the canopies of the tallest trees prevent much of the sunlight from reaching the interior of the forest (only 1% of that energy reaches the ground). This slows the development of several plant species, while others (such as bromeliads, epiphytes and ferns) develop on the trunks of trees as a way to be closer to the light.
The soil of tropical forests is poor in mineral nutrients, but the recycling of organic matter is very rapid. Fungi and bacteria present in the soil take about two months to decompose a leaf, while in a temperate forest, that leaf would take one to seven years to decompose.
The result of this decomposition are mineral nutrients that are absorbed by plants immediately and used in photosynthesis and their metabolism. That way, the nutrients are in the vegetables, and not concentrated in the soil.
As for fauna, you can find many vertebrate animals such as mammals, reptiles, amphibians, birds and invertebrates such as insects. Because we live in a hot climate with an abundance of water, the organisms that live there are always active.
Tropical forests are divided into at least five layers that are different and vary from forest to forest:
Sky: The layer called “sky” encompasses the spaced crowns of trees and their branches.
Crown: the layer called “crown” is made up of trees with short spacing and high density.
Sub: in this more spaced layer, tree species are present that reach 100 meters in height, located in a spaced manner.
Shrubby: Shrubs are the reason for the so-called “shrub layer”, with smaller trees, 5 to 20 meters above the ground.
Floor: this layer contains smaller vegetation, as well as trunks and mushrooms.
Among the peculiarities of humid tropical forests is the structure called canopy, formed by foliage, dry branches and other overlapping plant residues that are deposited on the ground. The canopy can exceed 25 meters in height and up to 70% of the forest’s life is concentrated there.
toads , birds, cobras, cats and monkeys live in the canopy . The characteristics of the canopy change over the course of the day, being drier and hotter than in other places in the forest.
Another structure of the humid tropical forest is called the “floor,” a dark, humid place below the canopy. On the forest floor, in constant shade, the decomposition of materials occurs by fungi and microorganisms that decompose dead plants and animals.
It is a process of recycling material that allows life in the forest, the presence of nutrients and survival of plants. In this part of the forest there are animals such as big cats, tapirs and elephants.
Unfortunately, tropical forests are being greatly destroyed by man. When this happens, they lose the natural protection against erosion caused by wind, water and other factors.
With the felling of trees, rainwater drags all the mineral nutrients to the bottom of the soil, a process called leaching, making those nutrients unnecessary for the plant, which reduces its fertility.
In addition to that, the soil that comes out of erosion is carried to the bottom of rivers, causing sediment to accumulate and causing flooding.
With the destruction of tropical forests, in addition to losing soil protection, thousands of plant and animal species are also lost.
With respect to the atmosphere, the importance of tropical forests lies in their function of lowering temperatures, functioning as a kind of air conditioning.
In addition to that, this biome has the property of “pumping” rainwater and subsoil water into the atmosphere, in a process known as evapotranspiration, which provides moisture that moves to other areas.