These incredible
places cover only 6 %of the Earth's surface but yet they contain MORE THAN 1/2
of the world's plant and animal species!
Tropical forests
contain more species than any other ecosystem, as well as a higher proportion of
endemic (unique) species. As people clear large areas of tropical forests,
entire species are vanishing, many of them unknown.
A Rainforest can be
described as a tall, dense jungle. The reason it is called a "rain" forest is
because of the high amount of rainfall it gets per year.A tropical rain forest
gets more than 60 inches (1.5 meters) of rain per year, although some regularly
get more than 200 inches (five meters).
There are two types
of rainforests, tropical and temperate. Tropical rainforests are found closer to
the equator and temperate rainforests are found farther north near coastal
areas. The majority of common houseplants come from the rainforest.
NASA TERRA Satellite Global Vegetation Image
The largest tropical
rainforests exist in the Amazon Basin (the Amazon Rainforest), in Nicaragua (Los
Guatuzos, Bosawï and Indio-Maiz), the southern Yucat�n Peninsula-El
Peten-Belize contiguous area of Central America (including the Calakmul
Biosphere Reserve), in much of equatorial Africa from Cameroon to the Democratic
Republic of Congo, in much of southeastern Asia from Myanmar to Indonesia and
Papua New Guinea, eastern Queensland, Australia and in some parts of the United
States. The majority of tropical rainforest is found within a 20 degree band
around the equator.
Outside of the
tropics, temperate rainforests can be found in British Columbia, southeastern
Alaska, western Oregon and Washington, the northern coast of California,
Scotland and Norway, the western Caucasus (Ajaria region of Georgia), parts of
the western Balkans, Japan, southern Chile, New Zealand, Tasmania, and parts of
eastern Australia.
MODIS Land Group/Vegetation Indices, Alfredo Huete, Principal Investigator, and
Kamel Didan, University of Arizona. Satellite: Terra Sensor: MODIS
Amazon Rainforest
Congo Rainforest
Layers Of A
Rainforest
EMERGENT LAYER
The tallest trees are the
emergents, towering as much as 200 feet above the forest floor with trunks that
measure up to 16 feet around. Most of these trees are broad-leaved, hardwood
evergreens. Sunlight is plentiful up here. Animals found are birds, butterflies
and small monkeys live with bats, snakes and bugs.
CANOPY LAYER
This is the primary
layer of the forest and forms a roof over the two remaining layers. Most canopy
trees have smooth, oval leaves that come to a point. It's a maze of leaves and
branches. Many animals live in this area since food is abundant. The canopy is
the home to birds, monkeys, frogs, and sloths, as well as lizards, snakes and
many insects.
UNDERSTORY LAYER
Little sunshine reaches this area
so the plants have to grow larger leaves to reach the sunlight. The plants in
this area seldom grow to 12 feet. This layer is the home to birds, butterflies,
frogs and snakes
SHRUB LAYER
This is the layer that grows
between the smaller trees of the understory and the forest floor. This layer is
made up of ferns and small shrubs.
FOREST FLOOR
The forest floor is very dark.
This is due to the trees above stopping the sunlight from entering the forest.
It is estimated that only 2% of the sunlight actually reaches the floor. The
soil on the floor is covered in a layer of leaves, twigs and dead plants, which
rot down quickly to provide nutrients for the plants. The leaf litter is alive
with invertebrates and microorganisms, which quickly rot down this surface
layer. Mosses and ferns grow on the forest floor where it is warm, damp and
shady. The soil is very sandy with only a thin layer of rotting vegetation.
Without the trees, the soil quickly loses its ability to support plants and
turns to desert-like conditions. The forest floor is home to some of the larger
animals of the forest such as tigers and elephants in Asia, gorillas and
leopards in Africa and tapirs and jaguars in South America.
Rainforest Destruction
Tropical forests of all varieties are disappearing rapidly as humans clear the
natural landscape to make room for farms and pastures, to harvest timber for
construction and fuel, and to build roads and urban areas. Although
deforestation meets some human needs, it also has profound, sometimes
devastating, consequences, including social conflict, extinction of plants and
animals, and climate change—challenges that aren’t just local, but global.
The reasons for forest destruction vary greatly from continent to continent and
from country to country. The forests are being destroyed at an accelerating pace
tracking the rapid pace of human population growth. There are many causes,
ranging from slow forest degradation to sudden and catastrophic clearcutting,
slash-and-burn, urban development, acid rain, and wildfires. Deforestation can
be the result of the deliberate removal of forest cover for agriculture or urban
development, or it can be a consequence of grazing animals, primarily for
agriculture.
Rainforests are the most productive
and most complex ecosystems on Earth.Rainforests are a key element of global
weather systems. Destroying them alters the Hydrological Cycle-causing drought,
flooding and soil erosion in areas where events were previously rare.
The cutting and destruction of the Rainforests also changes the albedo or
reflectivity of the Earth's Surface , which in turn alters wind and ocean
current patterns, and changes rain fall distribution.
Borneo Rainforest Destuction-UNEP
Map
Estimate of Global
Rates of Rainforest Destruction
2.47 acres (1 hectare) per
second: equivalent to two U.S. football fields
150 acres (60 hectares) per
minute
214,000 acres (86,000
hectares) per day: an area larger than New York City
78 million acres (31 million
hectares) per year: an area larger than Poland
Most of the rainforest destruction has occurred in the last 50 years, with
forests being destroyed at an alarming rate.
Rainforest Facts
80% of the ancient forests have been destroyed
only 20% of the ancient forests remain intact
Rainforests are home to more species of plants and animals than the rest
of the world put together.
An astounding number of fruits (bananas, citrus), vegetables (peppers,
okra), nuts (cashews, peanuts), drinks (coffee, tea, cola), oils (palm,
coconut), flavorings (cocoa, vanilla, sugar, spices), and other foods
(beans, grains, fish) come from rainforests.
Tropical forest fibers are found in rugs, mattresses, ropes and strings,
fabrics, industrial processes, and more.
Tropical forest oils, gums and resins are found in insecticides, rubber
products, fuel, paint, varnish and wood finishing products, cosmetics,
soaps, shampoos, perfumes, disinfectants, and detergents.
Madagascar is 2% of Africa's landmass but has 10,000 species of plants
-- 80% are endemic (found no where else in the world).
The Amazon River is the world's largest river system. Its annual outflow
accounts for one-fifth of all the fresh water that drains into the
world's oceans.
780 tree species have been found in a 10 hectare plot of Malaysian
rainforest -- more than the total number of tree species native to the
US and Canada.
In 1800, there were 2.9 billion hectares of tropical forest worldwide.
There are 1.5 billion hectares of tropical forest remaining.
Between 1960-1990, 445 million hectares of tropical forest were cleared.
Asia lost almost a third of its tropical forest cover between 1960-1980
-- the world's highest rate of forest clearance.
Almost 90% of West Africa's rainforest has been destroyed.
We lose 50 species every day -- 2 species per hour -- due to tropical
deforestation.
Tropical rainforests act as a global air conditioner -- by storing and
absorbing carbon dioxide from the air, storing the carbon, and releasing
fresh, clean oxygen.
Tropical forests yield some of the world's most beautiful and valuable
woods, such as teak, mahogany, rosewood, balsa, and sandalwood. These
woods surround us at home, in shops, and in offices.
About 50% of all mammals and 25% of all bird species in peninsular
Malaysia will become extinct by the year 2020 if the rainforest
destruction continues.
Over 50% of the Earth's species live in tropical forests.
Over 2000 tropical forest plants have been identified as having
anti-cancer properties. However, scientists have only tested 1 in 10
tropical forest plants for these properties and only intensively
screened 1 in 100.
90% of all primates are found in tropical forests.
Madagascar is home to all of the world's lemurs -- all are endangered.
Almost 90% of Madagascar's forests have been destroyed.
In Southeast Asia, traditional healers use 6,500 different tropical
plants.
Before 1500, there were approximately 6 million native people living in
Brazilian Amazonia. By 2000 there were less than 250,000.
75% of Australia's tropical rainforest has been cleared since the late
1700s.
Over 90 different Amazonian tribes are thought to have disappeared in
the 20th century.
It takes 60 years for a tropical rainforest tree to grow big enough to
be used for timber.
Tropical rainforests cover 6% of the earth's surface and contain over
50% of the earth's species.
Over 2000 rainforest plants have been shown to have anti-cancer
properties.
Tropical rainforest temperatures are high all year around at between 20
- 30 C
Approximately 80% of all insect species live in tropical rainforests
1 in 5 of all the birds on Earth live in Amazonia
Only 4% of the world's tropical rainforests are protected.
More than 9000 species of orchids grow on tropical trees.
The largest flower on Earth comes from a tropical forest - the Rafflesia
grows up to 1 metre across.
Costa Rica was the first Central American nation to cultivate coffee.
Costa Rica was the first Central American nation to cultivate bananas
for export.
The developing countries, which account for most of the tropical
rainforests, have almost 75% of the world's people but only about 15% of
the world's goods.
Unlike our forests most of the nutrients of a rainforest are stored in
its vegetation rather than in its soil.
The common way to clear land for agriculture or ranching is by felling
and burning the trees
Some 25% of all medicines used by Americans originated in a tropical
rainforest.
Many species of plants and animals are disappearing from the rainforests
before they can be catalogued and studied.
In most tropical countries only one tree is replanted for every ten cut.
About 2,000 trees per minute are cut down in the rainforests.
Half the rainfall in Amazonia returns to the atmosphere through the
process of transpiration.
In the tropics, wood is the main source of energy for cooking for
millions of poor, rural people.
Almost 65% of Central America has been cleared to create pastureland for
grazing cattle.
Rainforest land cleared for pasture or farming degrades quickly and is
usually abandoned.
The Ganges Plain, in India, is the most densely populated region in the
world. It has suffered severe flooding because of deforestation.
Most of the forests in India and Nepal have been cleared for
agriculture.
Use of powerful pesticides on banana plantations in Costa Rica has
killed huge numbers of fish in nearby rivers and streams.
In Papua New Guinea, butterfly farms are a successful operation that
provides income and supports forest preservation.
In the 20th century, 90 tribes of native peoples have been wiped out in
Brazil alone.
Some of the medical problems solved with rainforest plants include: a.
malaria (the bark of the cinchona tree produces quinine) b. a muscle
relaxant used during surgery (curare, a vine extract used by indigenous
peoples to poison arrows and darts) c. strokes, seizure, depression and
Alzheimer's disease (secretions of an Amazonian frog called Phyllomedusa
bicolor)
The rainforest is home to 155,000 out of 225,000 plant species known in
the world
Just 100 hectares of Amazon rainforest can contain up to 1500 different
plant species
For every tropical plant species that becomes extinct it is thought that
20 insects are certain not to survive.
Only 3% of all tropical tree species used for timber and paper products
are grown in plantations
