Tropical rainforests are so big that they are divided into four zones. The top layer of the rainforest is called the emergent layer. Giant trees grow here that are much taller than the trees below. The next layer is the canopy. It contains trees standing 60 to feet 18 to 45 meters tall. Their branches form a canopy, like a big beach umbrella that shades the forest floor.
Thick, woody vines are found in the canopy. Over 2, species of vines grow in the rainforest. Some vines, called lianas, are sometimes as big around as a person! They climb the trees in the canopy to reach for sunlight. The next layer, the understory, is a dark, cool area below the canopy, but above the ground. The understory is shaded from much of the sunlight by the canopy. The forest floor is the bottom layer of the rainforest.
This is the area where fallen, decomposing plants and trees lay on the ground. Many insects live here. Temperate rainforests have all of these zones except the emergent layer. The tallest trees in the temperate rainforest canopy grow to be about feet 90 meters tall. Scientists believe that there is such a great diversity of animals in tropical rainforests because they are one of the oldest ecosystems on earth.
Some forests in Southeast Asia have been around for at least million years, ever since dinosaurs roamed the earth. Animals in the tropical rainforest are specially adapted to live in this unique environment.
A common characteristic found among mammals, birds, reptiles and amphibians, is an adaptation to living in trees. One example is New World monkeys that have prehensile tails that curl around branches allowing the monkey to hold onto the tree with its tail!
Some plants even live on others. These are the epiphytes, plants that do not come into contact with the Earth but also are not parasites. They are partly responsible for giving the rain forest its "jungly" appearance. Mosses, lichens, and ferns cover just about anything else. Many seedlings germinate on fallen, decaying trees. Eventually the log rots completely away and a row of young trees is left, up on stilt-like roots, all in a row. The thick and protective vegetation also provides excellent habitats for the animals of the rain forest.
In turn, they contribute to the health of the forest by keeping the rampant vegetation under control by browsing. Tropical rain forests are located in the warm regions south of the Tropic of Cancer and north of the Tropic of Capricorn. Tropical rain forests have the greatest biodiversity, and the only tropical rain forest in the United States is found on the island of Puerto Rico.
Tropical rain forests are warm areas that receive a great deal of rainfall. Average temperatures range from degrees F. Rainfall ranges from inches per year. Only a small percentage of the tropical forests are rain forests. Most tropical rain forest soils are relatively poor in nutrients. Millions of years of weathering and torrential rains have washed most of the nutrients out of the soil. More recent volcanic soils, however, can be very fertile.
Tropical rain forest soils contain less organic matter than temperate forests and most of the available nutrients are found in the living plant and animal material.
Nutrients in the soil are often in forms that are not accessible by plants. Constant warmth and moisture promote rapid decay of organic matter. When a tree dies in the rain forest, living organisms quickly absorb the nutrients before they have a chance to be washed away.
When tropical forests are cut and burned, heavy rains can quickly wash the released nutrients away, leaving the soil even more impoverished. Emergent Layer -- These giant trees thrust above the dense canopy layer and have huge mushroom-shaped crowns. These trees enjoy the greatest amount of sunlight but also must endure high temperatures, low humidity, and strong winds. Many animals are illegally captured and end up in the pet trade.
Pet iguanas and parrots could be bred in captivity rather than removed from their native habitat. Ecotourism has brought many people to view and experience the rain forest. This business produces income for local inhabitants in a way that is less destructive than using the forest as farmland. Ecotourism may also create problems, however, as more people seek remote areas of the rain forest.
Art Explosion Art Explosion Illegally captured parrots can end up in pet stores. A treehouse built so that tourists can experience life in the canopy. Data is available to scientists that suggests the amount of carbon dioxide in the atmosphere is increasing.
This is good for plants that use it in photosynthesis to make food. But global temperatures may also be rising. This affects precipitation patterns. Precipitation has increased by about one percent over the world's continents in the last century. High latitude areas are tending to see more significant increases in rainfall, while precipitation has actually declined in many tropical areas. Art Explosion. Data from Missouri Botanical Garden. Rain forests are characterized by moisture.
The average rainfall in the rain forest is the highest for any ecoregion on Earth. Rivers in the rain forest provide more than water; they are also essential for transportation of goods for the human inhabitants.
Shallow soil cannot hold up the giant rain-forest trees without the added support of buttress roots that flare out from the base. Coffee and spices sold at an outdoor market are the same as those found in grocery stores throughout the world. The easiest way to clear the forest to create farmland is to cut and burn.
When nutrients are depleted, the land is abandoned and a new area is cleared. The water cycle repeats often along the equator. The main plants in this biome are trees.
A lot of the rain that falls on the rain forest never reaches the ground. It stays on the trees because the leaves act as a shield, and some rain never gets past the trees to the smaller plants and grounds below. Trees in this climate reach a height of more than feet. They form a canopy. The forest floor is called understory. The canopy also keeps sunlight from reaching the plants in the understory. Between the canopy and understory is a lower canopy made up of smaller trees.
These plants do receive some filtered sunlight. The tropical rain forest is classified as Af meaning tropical forest The A is given to tropical climates that are moist for all months which have average temperatures above 18 degrees Celsius.
The f stands for sufficient precipitation for all months. The annual precipitation of a rain forest is greater than cm. In only a month the rain forest receives 4 inches of rain. The rain forest is different from a lot of other climates.
The rain forest is about the same temperature year round. Rain forests are so hot because they are found near the equator. The closer to the equator you are, the more solar radiation there is. The more solar radiation there is, the hotter it is. All the plants will die out if the rain forest is cooler. The plants that make up the understory of a rainforest have adapted to the small amount of sunlight that they receive.
Ferns and mosses do well, along with epiphytes.
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