Tropical
Rainforest Adaptations
In
sharp contrast, the climate of the tropical rainforest is hot and wet. With
over 80 inches of rain per year, as opposed to the desert's 10 inches or less,
plants have adaptations that enable them to shed
water efficiently. The leaves of many rainforest plants have drip tips for this
purpose. Buttress and stilt roots are thought to provide extra support for
trees growing in spongy, wet soils.
Tropical rainforest plants also have adaptations to take in what little sunlight is available on the dark forest floor. Large leaves are common; they increase the amount of sunlight a plant can capture. Other plants, like orchids, bromeliads and ferns, grow as epiphytes high up in the canopy where there is more sunlight.
Types of Rainforests
There are two types of rainforests -- tropical and temperate. Tropical and temperate rainforests share certain characteristics. For example, most trees flare at the base. Vegetation is dense, tall and very green. Both types of rainforests are rich in plant and animal species, although the diversity is greater in the tropical rainforest.
Montane forests are found in mountainous areas and may contain plants such as oaks, rhododendrons, and pines, which are characteristic of temperate deciduous forests. At higher altitudes, temperatures are cooler. Even close to the equator, frost and snow can occur.
Precipitation
and Climate
Both
tropical and temperate rainforests are very lush and wet. The tropical
rainforest has downpours at the rate of two inches an hour adding up to some
400 inches of rain per year. It rains a lot in the temperate rainforest, too --
about 100 inches per year. And even more moisture comes from the coastal fog
that hovers among the trees.
Tropical rainforests are warm and moist; while temperate rainforests are cool.
|
Tropical |
Temperate |
|
|
Temperatures |
warm |
cool |
|
Number of tree species |
many (hundreds) |
few (10-20) |
|
Types of leaves |
broadleaf |
needles |
|
Age of trees |
50-100 years |
500-1000 years |
|
Epiphytes |
lots of different kinds including orchids and bromeliads |
mostly mosses and ferns |
|
Decomposition rate |
rapid |
slow |
Are all
Tropical Forests, Rainforests?
Only
a small percentage of the tropical forests are rainforests. To be a tropical
rainforest, forested areas must:
· Lie between the Tropic of Cancer and the Tropic of Capricorn.
· Receive rainfall regularly throughout the year (80- 400 inches per year).
· Remain warm and frost free all year long (mean temperatures are between 70° and 85°F) with very little daily fluctuation.
Consequently, many forested areas in the tropics are not rainforests. Forests that receive irregular rainfall (monsoons followed by a dry season) are moist deciduous forests. Trees in these forests may drop their leaves in the dry season.

Where Are Rainforests Located?
Tropical rainforests are located near the equator. Fifty seven percent of all tropical rainforests are found in Latin America. One third of the world's tropical rainforests are in Brazil. Other tropical rainforests are located in Southeast Asia and the Pacific Islands (1/4 of the world's tropical rainforests) and West Africa (9/50).
Temperate rainforests are found along some coasts in temperate zones. The largest temperate rainforests are found on the Pacific coast of North America. They stretch from Oregon to Alaska for 1,200 miles. Smaller temperate rainforests can be found on the southeast coast of Chile in South America. There are a few other coastal strips with temperate rainforests, including small areas in the United Kingdom, Norway, Japan, New Zealand, and southern Australia.

http://mbgnet.mobot.org/sets/rforest/index.htm
A map of the Tropical Rainforests in the world
The Disappearing Rainforests
·
We are losing Earth's greatest biological treasures just as we are
beginning to appreciate their true value. Rainforests once covered 14% of the
earth's land surface; now they cover a mere 6% and experts estimate that the
last remaining rainforests could be consumed in less than 40 years
·
One and one-half acres of rainforest are lost every second with tragic
consequences for both developing and industrial countries.
·
Rainforests are being destroyed because the value of rainforest land is
percieved as only the value of its timber by short-sighted governments,
multi-national logging companies, and land owners.
·
Nearly half of the world's species of plants, animals and microoganisms
will be destroyed or severely threatened over the next quarter century due to
Rainforest deforestation.
·
Experts estimates that we are losing 137 plant, animal and insect
species every single day due to rainforest deforestation. That equates to
50,000 species a year. As the rainforest species dissapear, so do many possible
cures for life-threatening diseases. Currently, 121 prescription drugs sold
worldwide come from plant-derived sources. While 25% of Western pharmaceuticals
are derived from rainforest ingredients, less that 1% of these tropical trees and
plants have been tested by scientists.
·
Most rainforests are cleared by chainsaws, bulldozers and fires for its
timber value and then are followed by farming and ranching operations, even by
world giants like Mitsubishi Corporation, Gerogia Pacific, Texaco and Unocal.
·
There were an estimated ten million Indians living in the Amazonian
Rainforest five centuries ago. Today there are less than 200,000.
·
In Brazil alone, European colonists have destroyed more than 90
indigenous tribes since the 1900's. With them have gone centuries of
accumulated knowledge of the medicinal value of rainforest species. As their
homelands continue to be destoyed by deforestation, rainforest peoples are also
dissappearing.
·
Most medicine men and shamans remaining in the Rainforests today are 70
years old or more. Each time a Rainforest medicine man dies, it is as if a
library has burned down.
·
When a medicine man dies without passing his arts on to the next
generation, the tribe and the world loses thousands of years of irreplaceable
knowledge about medicinal plants.
The Wealth of the Rainforests
·
The Amazonian Rainforest covers over a billion acres, encompassing
areas in Brazil, Venezuela, Columbia and the Eastern Andean region of Ecuador
and Peru. If Amazonia were a country, it would be the ninth largest in the
world.
·
The Amazon Rainforest has been described as the "Lungs of our
Planet" because it provides the essential environmental world service of
continuously recyling carbon dioxide into oxygen. More than 20 percent of the world
oxygen is produced in the Amazon Rainforest.
·
More than half of the world's estimated 10 million species of plants,
animals and insects live in the tropical rainforests. One-fifth of the world's
fresh water is in the Amazon Basin.
·
One hectare (2.47 acres) may contain over 750 types of trees and 1500
species of higher plants.
·
At least 80% of the developed world's diet originated in the tropical
rainforest. Its bountiful gifts to the world include fruits like avocados,
coconuts, figs, oranges, lemons, grapefuit, bananas, guavas, pinapples, mangos
and tomatoes; vegetables including corn, potatoes, rice, winter squash and
yams; spices like black pepper, cayenne, chocolate, cinnamon, cloves, ginger,
sugar cane, tumeric, coffee and vanilla and nuts including Brazil nuts and
cashews.
·
At least 3000 fruits are found in the rainforests; of these only 200
are now in use in the Western World. The Indians of the rainforest use over
2,000.
·
Rainforest plants are rich in secondary metabolites, particularly
alkaloids. Biochemists believe alkaloids protect plants from disease and insect
attacks.Many alkaloids from higher plants have proven to be of medicinal value
and benefit.
·
Currently, 121 prescription drugs currently sold worldwide come from
plant-derived sources. And while 25% of Western pharmaceuticals are derived
from rainforest ingredients, less than 1% of these tropical trees and plants
have been tested by scientists.
·
The U.S. National Cancer Institute has identified 3000 plants that are
active against cancer cells. 70% of these plants are found in the rainforest.
Twenty-five percent of the active ingredients in today's cancer-fighting drugs
come from organisms found only in the rainforest
·
Vincristine, extracted from the rainforest plant, Periwinkle, is one of the world's most
powerful anticancer drugs. It has dramatically increased the survival rate for
acute childhood leukemia since its discovery.
·
In 1983, there were no U.S. pharmaceutical manufacturers involved in
research programs to discover new drugs or cures from plants. Today, over 100
pharmaceutical companies and several branches of the US government, including
giants like Merck and The National Cancer Institute, are engaged in plant
research projects for possible drugs and cures for viruses, infections, cancer
and even AIDS.
Rainforest Action
·
Experts agree that by leaving the rainforests intact and harvesting
it's many nuts, fruits, oil-producing plants, and medicinal plants, the
rainforest has more economic value than if they were cut down to make grazing
land for cattle or for timber..
·
The latest statistics show that rainforest land converted to cattle
operations yields the land owner $60 per acre and if timber is harvested, the
land is worth $400 per acre. However, if these renewable and sustainable
resources are harvested, the land will yield the land owner $2,400 per acre.
·
If managed properly, the rainforest can provide the world's need for
these natural resources on a perpetual basis.
·
Promoting the use of these sustainable and renewable sources could stop
the destruction of the Rainforests. By creating a new source of income
harvesting the medicinal plants, fruits nuts, oil and other sustainable
resources, the rainforests is be more valuable alive than cut and burned.
·
Sufficient demand of sustainable and ecologically havested Rainforest
products is necessary for preservation efforts to succeed. Purchasing
sustainable rainforest products can effect positive change by creating a market
for these products while supporting the native people's economy and provides
the economic solution and alternative to cutting the forest just for the value
of its timber.
The Destruction of the
Majestic Rainforest
The beauty, majesty and timelessness of a primary rainforest is indescribable.
It is impossible to capture on film, to describe in words or to explain to
those who have never had the awe-inspiring experience of standing in the heart
of a primary rainforest. Rainforests have evolved over millions of years to
turn into the incredibly complex environments they are today. A rainforest
represents a store of living and breathing renewable natural resources, which
have for eons, by virtue of their richness in both animal and plant species,
contributed a wealth of resources for the survival and well-being of man. These
have included basic food supplies, clothing, shelter, fuel, spices, industrial
raw materials and medicine for all those that have lived sustainably in the
majesty of the forest. However, the inner dynamics of a tropical rainforest are
an intricate and fragile system where everything is so interdependent that
upsetting one part can lead to unknown damage or even destruction of the whole.
Sadly, it has taken only a century of man's intervention to destroy what nature
has so intricately designed to last forever.
In 1950, 15% of the earth's land surface was covered by rainforest.
Today, more than half has already gone up in smoke. A century ago, half of
India and a third of Ethiopia were covered by forest, now only fourteen percent
in India remains and only one-third is left in Ethiopia. Eight out of ten trees
in Ghana have been cut down. Three quarters of the trees of the Ivory Coast are
gone. More than twenty percent of the Amazon Rainforest is already gone and
much more is severely threatened as destruction continues to escalate.
Statistics reported in 1996 reported the Amazon showed a 34 percent increase in
deforestation since 1992. A new report by a congressional committee says the
Amazon is vanishing at a rate of 20,000 square miles a year. That's more than
three times the rate of 1994, the last year for which official figures are
available. "If nothing is done, the entire Amazon will be gone within 50
years," said the 110-page report's author, Rep. Gilney Vianna of the
leftist Worker's Party in the Amazon state of Mato Grosso. Yet another recent
report said new figures showed that in the Brazilian Amazon, forest fires
increased by more than 50 percent over 1996.
In less than 50 years, more than half of the world's tropical
rainforests have fallen victim to fire and the chain saw and the rate of
destruction is still accelerating. Unbelievably, over 200,000 acres of
rainforest are burned every day. That is over 150 acres lost every minute of
every day, and 78 million acres are lost every year! More tropical forest
burned around the world in 1997 than at any other time in recorded history, a
report by the World Wide Fund for Nature. The fund said "1997 will be
remembered as the year the world caught fire," said Jean-Paul Jeanrenaud,
head of its forest program.
Massive deforestation brings with it many ugly consequences - air and
water pollution, soil erosion, malaria epidemics, the release of carbon dioxide
into the atmosphere, the eviction and decimation of Indigenous Indian tribes,
and the loss of biodiversity through extinction of plants and animals. Less
Rainforests means less rain, less oxygen for us to breathe, and an even greater
threat from global warming.
But who is really to blame? Consider what we industrialized Americans
have done to our own homeland... we converted ninety percent of North America's
virgin forests into firewood, shingles, furniture, railroad ties and paper.
Other industrialized countries have done no better. Malaysia, Indonesia and
Brazil, among other tropical countries with rainforests, are often branded as
"environmental villains" of the world, mainly due to their reported
levels of destruction of their rainforests. But despite the levels of
deforestation, they are still covered by up to 60% of their territory by
natural tropical forests. In fact, much of the pressure today on their
remaining rainforests come from servicing the needs and markets for wood
products in industrialized countries who have already depleted their own
natural resources. Industrial countries would not be buying rainforest
hardwoods and timber had we not cut down our own trees long ago nor would
poachers in the Amazon jungle be slaughtering jaguar, ocelot, caiman and otter
if we did not provide lucrative markets for their skins in Berlin, Paris and
Tokyo.
Tropical Rainforest Animals
Life inside the wet and bustling tropical rainforest is filled with danger. Cougars and pumas stand ready to pounce; snakes sliver unseen between feet to administer a lethal bite; while exotic birds chirp overhead. An animal must be both smart and strong to survive in this environment. The intense competition from other species makes rainforest species the most interesting.
The rainforests of the world are being destroyed by loggers and development. Many species found in the rainforest are endangered. Once they disappear, they are gone forever!
We will be classifying Rainforest Animals into 3 Groups.
1.
Endangered Animals
2.
Extinction
3.
Abundant
In Endangered Animals, we can classify the Orangutan,
Gorrila and many other spieces of animals.
In Extinction, we can classify these animals.
In Abundant, there are a lot of animals in
the rainforest. But because of Man’s activities, these animals will soon join
the Endangered animals section or even the Extinct section. For example the Dodo
which lived hundred’ of years ago were killed so often that they became
extinct.
P.S If you cannot see the pictures, please
call me, I shall e-mail it you. By the way I shall check my e-mail at 11.10,
write all your suggestions by then in e-mail, and sent it to me at darthmaulempire@msn.com
Gautham