UPSIDE-DOWN AND ENDANGERED - THE ECOSYSTEM OF THE RAINFOREST

by Pam North

Rainforests are one of nature's most amazing ecosystems.  Comprising
only 6% of the earth's landmass, they are home to 50% of the world's
life.  They have an average year-round temperature of 70 degrees F,
and annual rainfall of more than 60 inches (up to 400 inches in some
areas of the Amazon).  Rainforests are the reverse of temperate-climate 
forests; it's the canopy of plants above that stores the nutrients 
rather than the soil.  Deciduous trees in the temperate-climate forests 
all shed their leaves at seasonal changes, and the dead leaves eventually 
decompose on the ground to become rich soil.  Tropical trees lose their 
leaves year aroun,d and the constant hot climate triggers the growth of 
fungi, bacteria and insects to feed on the dead leaves, resulting in a
rapid decomposition that takes only a few weeks compared to one to seven 
years in a temperate climate.  Rich soil has little opportunity to
build up in the rainforest; heavy annual amounts of rain would carry 
away all topsoil if it weren't for the rainforests' protective canopy 
to shield the earth beneath from the downpours, and also from the hot
sun that soon would render the earth hard-packed and unproductive, its 
remaining nutrients leached away. An estimated 20% of all oxygen 
generated by the earth's plants is produced in the Amazon, and the 
rainforests' climate moderation is crucial in maintaining the fragile 
balance that offsets the greenhouse effect that results from rising 
temperatures and decreasing rainfall.  
 
Rainforests are disappearing at an alarming rate; nearly half are gone
forever, and most of this reduction has occurred since 1960.  Forty to
fifty million acres of the Amazon jungle are cut or burned annually,
and the bared land will support agriculture or livestock for only a
few years; the soil and its nutrients disappear, the rainfall
diminishes and the forest is irreversibly gone. At the rate of current
bulldozing and damage, it will take less than fifty years to destroy
the remaining jungle; the Amazon could be completely gone by the year
2040.  Species of animal and plant life are becoming extinct before
even being discovered; scientists believe only about one-sixth of
these species have been found and identified so far.  Roughly 25% of
all prescription drugs contain ingredients originating from the
rainforest, and other plants with as yet unknown curing properties may
disappear before their benefits are ever utilized.

For another perspective on the importance of rainforests, consider the
following facts: More types of woody plant species grow on the slopes
of a single forested volcano in the Philippines than grow in the
entire United States.  Tiny Panama's forests contain as many plant
species as all of Europe, and more species of fish live in the Amazon
River than in the entire Atlantic Ocean.  Now remember that only an
approximate one-sixth of all the rainforests' species have been
discovered.

The Amazon is the largest rainforest on earth.  Between 100 and 250
different tree species can be found in a five-acre area there,
compared to a maximum of 15 species in North American forest
ecosystems; it is possible to travel a mile or more in the Amazon
before finding two trees of the same species.  More than 100 types of
plants and 1700 insects can exist in the branches of a single mature
tropical tree, and the Amazon has more than a million interdependent
and exotic species of plant and animal life, including trees with
6-foot-long leaves, flowers with petals 3 feet in length, plants that
can cradle 10 gallons of water in reservoirs formed by their leaves,
dinner plate-sized butterflies and bird-sized bees.

Next time you see one of those bumper stickers proclaiming the slogan,
"Save Our Rainforests," consider the ramifications of life without
those rainforests....if there can be any life at all.