Tropical Rain Forests Essay, Research Paper
TROPICAL RAIN FORESTS
Tropical rain forests are considered to possess more plants and animals than any other forests on earth. There is a seemingly endless array of unique species of both plants and animals. Unless you’ve been to a tropical rain forest, it’s difficult to grasp the idea of what a rich treasure they actually are. They are only found within 25 degrees of the equator, which enhances their appeal.(Caufield) In order to grasp this concept, you will need a quick overview of where these forests are located and what exactly is in a tropical rain forest.
The term “rain forest” was first fabricated in 1898 by a German botanist named Schimper, to describe forests that grow in constantly wet conditions. Rain forests can typically grow wherever the annual rainfall is more than 80 inches and evenly spread throughout the year. Rain forests are found in temperate climates as well as tropical climates, but tropical rain forests only grow in a narrow band around the equator. (Caufield)
In order to better understand tropical rain forests, you should know that there are many different types of tropical rain forests. They can be divided into two broad categories according to elevation. There are the lowland rain forests as well as the montane rain forests. Mixed in with these dominant forests are unique forests such as mangrove forests and flooded forests.
Lowland forests are by far the biggest, but because they are so easily accessible, they have suffered the most damage due to clearance. (Usually farmers clearing out the trees for farmland) The lowland forests are generally found under 3,000 feet, but only up to 1,800 feet in western Amazonia. These forests also have the largest of all plant communities in the world.(Gallant) The canopy can reach a height of more the 150 feet and consist of many different species of trees living close together. A few trees, call emergents, break through the canopy and often attain heights of 200 feet. These trees usually have a straight branchless trunk of 130 to 165 feet of the ground. The tallest broad-leaf tree ever recorded was a Koompassia excelsa from Sarawak. This monster tree stood over 270 feet tall!(Compton’s Encyclopedia)
Botanists have identified as many as 40 different types of lowland rain forest, differing mainly only in the amount of rainfall, soil fertility, and drainage. These different types of lowland forests are called specialized forests. For example, on free-draining sandy soils heath forest may be forced to grow. These are known s Kerangas in Borneo and as Caatinga in South America. Their flat canopy and many slender trees characterize these forests.
In most rainforests, there are very little nutrients in the soil. In response to this problem some plants have to come up with very elaborate ways of getting protein. Several species of carnivorous plants flourish in these difficult conditions. Due to the unique climate in a tropical rainforest, most of these plants and animals are only found in specific tropical forests.
Another unique type of lowland forest is the limestone forest. Very little is known about these forests because they are so rare. Scientists have discovered 130 new species that are found only in limestone forests. Another interesting fact about limestone forests is that they are very prone to fires, especially those caused by lightning. Some other types of lowland forests are beach forests, liana forests, bamboo forests, and ultra basic rocks.
As the altitude changes, so does the temperatures and rainfall, which has dramatic effect on the flora and fauna. The Montane rain forests are broken into three bands of elevation. Lower montane forests in the 3,000-6,600 foot range, upper montane forests in the 6,600-10,500 foot range, and sub alpine forest located up to 12,500 feet.(Collins) The canopy drops greatly as altitude rises. In lower montane forest the canopy is about 50-110 feet tall. On the other hand, in upper montane forests, the canopy can drop to as low as the height of a man. Features of the lowlands disappear, such as buttressed roots and fruits growing on trees. Lichens cling to the branches of the trees and water-dripping moss covers the trunks and ground. Ferns, orchids, and bromeliads become abundant. Trees lose their straight unbranched trunks and become gnarled, twisted, and multi-stemmed. These forests have very few tropical plants and greatly resemble the more temperate zones with large amounts of oak, beeches, and laurels.(Collins)
Throughout the tropics the large amount of rainfall is brought back to the ocean by many large rivers. These rivers often burst their banks, causing miles and miles of forest to be flooded. Botanists have identified as many as 40 different types of lowland rain forest, differing mainly only in the amount of rainfall, soil fertility, and drainage. Due to the varying degree of time these forests spend under water, it is almost impossible to generalize them. In a way, every flooded forest is unique in its own way because of how long, or how often the forest is flooded. Flooded forests are found in all three continental regions. Most of the flooded forest plants flower in the dry season when the water is the lowest. The sago palm is the most common type of tree found in flooded forests. Its height is definitely an advantage because in the wet season, which ranges from 4-7 months, the flooding can reach 40 feet in places.
The shores of the tropics often support mangrove forests. These forests are a special type of forest, which is poor in its variety of species. These forests are normal plant communities of sheltered tropical shores. They can extend all the way up the 32 degrees North and even farther in the southern hemisphere.(www.bev.net) The largest mangrove forests are found mainly on the coast of Bangladesh, the Malay Peninsula, Sumatra, Borneo, New Guinea, and other islands scattered throughout Southeast Asia. Mangroves are evergreen trees and shrubs which grow namely in silt-rich soils in saline coastal waters. These plants show a number of adaptations to the salty environment including breathable roots, or pneumatophores. These roots are also occasionally found in flooded freshwater forests. Mangrove forests may grow to be 100 feet tall, or shrubs only 10-15 feet tall.(www.bev.net)
The mangrove forests across the world can be divided into two groups. An eastern group on the coast of the Indian and western Pacific oceans, and a western group on the coasts of the Americas, the Caribbean, and West Africa. These two groups are very alike in their flora, but when it comes to fauna, only Fiji and the Tonga Islands in the Pacific have an eastern as well as a western species. The Rhizophora muncronata, and the Rhizophora mangle are only found on Fiji and Tonga.
Today over half of the worlds forests have already been demolished, and experts fear that those remaining forests will be gone or plundered by the year 2040.(Gallant) Man destroys 40 to 50 acres of forest each year, an area nearly as big as Washington State. You might ask yourself, what can I do to stop this? Or maybe who cares? Rain forests help conserve water prevent drought and flooding, and regulate local climates. The rain forests also have a large impact on the global climate. When the forest are cleared and burned, a large amount of carbon dioxide is added to the atmosphere, which contributes to global warning. Over half the worlds known plant and animal species are found in tropical rain forests. Scientists have only studied 10% of them. On top of the animals is the fact that over 7,000 medicines have been derived from tropical plants. It is definitely time to appreciate and conserve the magnificent tropical rainforests of the world.