Rainforests Essay, Research Paper

Science; Rainforests and Earth

The Tropical Rainforests of the World

In this term paper, I will explain the great importance of the tropical

Rainforests around the world and discuss the effects of the tragedy of

rainforest destruction and the effect that it is having on the earth. I will

talk about the efforts being made to help curb the rate of rainforest

destruction and the peoples of the rainforest, and I will explore a new topic

in the fight to save the rainforest, habitat fragmentation. Another topic being

discussed is the many different types of rainforest species and their

uniqueness from the rest of the world.

First, I will discuss the many species of rare and exotic animals, Native to

the Rainforest. Tropical Rainforests are home to many of the strangest looking

and most beautiful, largest and smallest, most dangerous and least frightening,

loudest and quietest animals on earth. There are many types of animals that

make their homes in the rainforest some of them include: jaguars, toucans,

parrots, gorillas, and tarantulas. There are so many fascinating animals in

tropical rainforest that millions have not even identified yet. In fact, about

half of the world?s species have not even been identified yet. But sadly, an

average of 35 species of rainforest animals are becoming extinct every day.

So many species of animals live in the rainforest than any other parts of the

world because rainforests are believed to be the oldest ecosystem on earth.

Some forests in southeast Asia have been around for at least 100 million years,

ever since the dinosaurs have roamed the earth. During the ice ages, the last

of which occurred about 10,000 years ago, the frozen areas of the North and

South Poles spread over much of the earth, causing huge numbers of extinctions.

But the giant freeze did not reach many tropical rainforests. Therefore, these

plants and animals could continue to evolve, developing into the most diverse

and complex ecosystems on earth.

The nearly perfect conditions for life also help contribute to the great number

of species. With temperatures constant at about 75-80 degrees Fahrenheit the

whole year, the animals don?t have to worry about freezing during the cold

winters or finding hot shade in the summers. They rarely have to search for

water, as rain falls almost every day in tropical rainforests.

Some rainforest species have populations that number in the millions. Other

species consist of only a few dozen individuals. Living in limited areas, most

of these species are found nowhere else on earth. For example, the maues

marmoset, a species of monkey, wasn?t discovered until recently. It?s entire

tiny population lives within a few square miles in the Amazon rainforest. This

species of monkey is so small that it could fit into a persons hand!

In a rainforest, it is difficult to see many things other than the millions of

insects creeping and crawling around in every layer of the forest. Scientists

estimate that there are more than 50 million different species of invertebrates

living in rainforests. A biologist researching the rainforest found 50

different of ants on a single tree in Peru! A few hours of poking around in a

rainforest would produce several insects unknown to science.

The constant search for food , water, sunlight and space is a 24-hour pushing

and shoving match. With this fierce competition, it is amazing that that so

many species of animals can all live together. But this is actually the cause

of the huge number of the different species.

The main secret lies in the ability of many animals to adapt to eating a

specific plant or animal, which few other species are able to eat. An example

of such adaptations would be the big beaks of the toucans and parrots. Their

beaks give them a great advantage over other birds with smaller beaks. The

fruits and nuts from many trees have evolved with a tough shell to protect them

from predators. In turn toucans and parrots developed large, strong beaks,

which serves as a nutcracker and provides them with many tasty meals.

Many animal species have developed relationships with each other that benefit

both species. Birds and mammal species love to eat the tasty fruits provided

by trees. Even fish living in the Amazon River rely on the fruits dropped from

forest trees. In turn, the fruit trees depend upon these animals to eat their

fruit, which helps them to spread their seeds to far – off parts of the forest.

In some cases both species are so dependent upon each other that if one becomes

extinct, the other will as well. This nearly happened with trees that relied

on the now extinct dodo birds. They once roamed Mauritius, a tropical island

located in the Indian Ocean. They became extinct during the late 19th century

when humans overhunted them. The calvaria tree stopped sprouting seeds soon

after. Scientists finally concluded that, for the seeds of the calvaria tree

to sprout, they needed to be digested by the dodo bird. By force feeding the

seeds to a domestic turkey, who digested the seeds the same way as the dodo

bird, the trees were saved. Unfortunately, humans will not be able to save

each species in this same way.

Each species has evolved with its own set of unique adaptations, ways of

helping them to survive. Every animal has the ability to protect itself from

being someone?s next meal. To prevent the extinction of a species each and

every species must develop a defense tactic. The following are just a few of

Mother Nature?s tricks.

? CAMOFLAGE

The coloring of some animals acts as protection from their predators. Insects

play some of the best hide-and-go-seek in the forest. The ?walking stick? is

one such insect; it blends in so well with the palm tree it calls its home that

no one would notice unless it?s moved. Some butterflies, when they close their

wings, look exactly like leaves. Camouflage also works in reverse, helping

predators, such as boa constrictors, sneak up on unsuspecting animals and

surprise them.

? SLOW AS A SNAIL

The tree-toed sloth is born with brown fur, but you would never know this by

looking at it. The green algae that makes its home in the sloths fur helps it

to blend in with the tops of the trees, the canopy, where it makes it?s home.

But even green algae isn’t the only thing living in a sloth?s fur; it is

literally ?bugged? with a variety of insects. 978 beetles were once found

living on one sloth.

The sloth has other clever adaptations. Famous for its snail-like pace; it is

one of the slowest moving animals on earth. It is so slow that it often takes

up to a month to digest it?s food. Although its tasty meat would make a good

meal for jaguars and other predators, most do not notice the sloth as it hangs

in the trees, high up in the canopy.

? DEADLY CREATURES

Other animals don?t want to announce their presence to the whole forest. Armed

with dangerous poisons used in life threatening situations, their bright colors

warn predators to stay away. This enables them to survive everyday emergency

situations.

The coral snake of the Amazon, with its brilliant red, yellow, and black

coloring, is recognized as one of the most beautiful snakes in the world, but

it is just as deadly as it is beautiful. The coral snake?s deadly poison can

kill in seconds. Other animals know to stay away from it.

The poison arrow frog also stands out with its brightly colored skin. It’s

skin produces some of the strongest natural poison in the world, which

indigenous people often use for hunting purposes. It’s poison is now being

tested for use in modern medicine.

In a single raiforest habitat, several species of squirels can live together

without harming one another. This bewilders many people, Louise Emmons found.

Why can nine species of squirrels live together? Well, in a brief summary each

of the nine species is a different size; three have specialized diets or

habitats, which leaves six species that feed on nuts, fruits and insects, and

so potentially compete for food. A closer look showed that three of the six, a

large, a medium, and a small one live in the forest canopy and never come to

the ground. The largest squirrel feeds mainly on very large, hard nuts, and

the smaller ones eat smaller fruits and nuts. The other three species, again a

large medium and small one live in the ground and eat fruits and nuts of the

same species as their canopy neighbors, but only after they fall to the ground.

Tropical rainforests are bursting with life. Not only do millions of species

of plants and animals live in rainforests, but many people also call the

rainforest their home. In fact, Indigenous, or native, people have lived in

rainforests for thousands of years. In North and South America they were

mistakenly named Indians by Christopher Columbus, who thought that he had

landed in Indonesia, then called the East Indies.

The native people of the rainforest live very different lives than us. In this

section, I will explain how very different our lives differ than from the

indigenous people of the rainforest. Although many indigenous people live very

much like we do, some still live as their ancestors did many years before them.

These groups organize their daily lives differently than our culture.

Everything they need to survive, from food to medicines to clothing, comes from

the forest.

? FOOD

Besides haunting, gathering wild fruits and nuts and fishing, Indigenous people

also plant small gardens for other sources of food, using a sustainable farming

method called shifting cultivating. First they clear a small area of land and

burn it. Then they plant many types of plants, to be used for food and

medicines. After a few years, the soil has become too poor to allow for more

crops to grow and weeds to start to take over. So they then move to a nearby

uncleared area. This land is traditionally allowed to regrow 10-50 years

before it is farmed again.

Shifting cultivation is still practiced by those tribes who have access to a

large amount of land. However, with the growing number of non-Indigenous

farmers and the shrinking rainforest, other tribes, especially in Indonesia and

Africa, are now forced to remain in one area. The land becomes a wasteland

after a few years of overuse, and cannot be used for future agriculture.

? EDUCATION

Most tribal children don?t go to schools like ours. Instead, they learn about

the forest around them from their parents and other people in the tribe. They

are taught how to survive in the forest. They learn how to hunt and fish, and

which plants are useful as medicines or food. Some of these children know more

about rainforests than scientists who have studied rainforests for many years.

The group of societies known as Europeans includes such cultures such as

Spanish and German. Similarly, the broad group, Indigenous peoples includes

many distinct culture groups, each with its own traditions. For instance,

plantains (a type of banana) are a major food source for the Yanonami from the

Amazon while the Penan of Borneo, Southeast Asia, depend on the sago palm (a

type of palm tree) for food and other uses.

All Indigenous people share their strong ties to the land. Because the

rainforest is so important for their culture, they want to take care of it.

They want to live what is called a sustainable existence, meaning they use the

land without doing harm to the plants and animals that also call the rainforest

their home. As a wise Indigenous man once said, ?The earth is our historian,

our educator, the provider of food, medicine, clothing and protection. She is

the mother of our races.?(11)

Indigenous peoples have been losing their lives and the land they live on ever

since Europeans began colonizing 500 years ago. Most of them died from common

European diseases which made Indigenous people very sick because they had never

had these diseases before. A disease such as the flu could possibly kill an

indigenous person because he/she has not been exposed to this disease before.

Many Indigenous groups have also been killed by settlers wanting their land, or

put to work as slaves to harvest the resources of the forest. Others were

converts to Christianity by missionaries, who forced them to live like

Europeans and give up their cultural traditions.

Until about forty years ago, the lack of roads prevented most outsiders from

exploiting the rainforest. These roads, constructed for timber and oil

companies, cattle ranchers and miners, have destroyed millions of acres each

year.

All of the practices force Indigenous people off their land. Because they do

not officially own it, governments and other outsiders do not recognize their

rights to the land. They have no other choice but to move to different areas,

sometimes even to the crowded cities. They often live in poverty because they

have no skills useful for a city lifestyle and little knowledge about the

culture. For example, they know more about gathering food from the forest than

buying food from a store. It?s like being forced to move to a different

country, where you knew nothing about the culture or language.

Indigenous groups are beginning to fight for their land, most often through

peaceful demonstrations. Such actions may cause them to be arrested or even to

lose their lives, but they know that if they take no action, their land and

culture could be lost forever. Kaypo Indians, for example, recently spoke to

the United States Congress to protest the building of dams in the Amazon, and

were arrested when they arrived back in Brazil, accused of being traitors to

their own country. In Malaysia, the Penean have arrested for blocking logging

roads.

Many people living outside of rainforests went to help protect the Indigenous

people?s culture. They understand that Indigenous people have much to teach us

about rainforests. Since we (the US and other countries) have been working

with the Indigenous People and other rainforest protection agencies, we have

learned many things about the forest, including it?s ecology, medicinal plants,

food and other products. It has also showed us how crucial it is for the

Indigenous people of the rainforest to continue their daily and traditional

activities because of their importance in the cycle if the rainforest. It has

shown us that they have the right to practice their own lifestyle, and live

upon the land where there ancestors have lived before them. (2)

One such example of a invasion of the Ingenious people?s privacy is a new so

called ?emergency? called the Cofan Emergency. This dispute is about an

Indigenous tribe called the Cofan. Historically, the Cofan occupied some half

a million acres of rainforest along the Aguarico River in the Ecuadorian

Amazon. Because their traditional territory has been significantly reduced

through invasions by oil companies such as Texaco, the Cofan now live in five

small, discontinuous communities. However, they still utilize and protect a

region of about 250,000 acres, including two reserves in the Amazon.

In addition to displacing the Cofan and other indigenous groups, oil

development, which began in this region over thirty years ago, has also caused

serious environmental destruction. The deforestation of some two million acres

of rainforest and contamination of the regions waterways has resulted in the

loss of plant and animal diversity, and drastically affected the social and

economic well-being of local Indigenous peoples. This devastation continues.

Last year, ten new concessions were licensed to international oil companies in

the Ecuadorian Amazon, opening an additional five million acres of forest to

oil development. One of these oil blocks, Block 11 awarded to the US-based

Santa Fe Energy, lies within Cofan territory and will directly affect at least

three communities.

In order to protect the remaining intact rainforest areas of their homeland and

the adjacent ecological reserves, the Cofan are seeking $5,000 to purchase an

outboard motor and a video camera, in order to coordinate between disperse

communities and document the destruction caused by oil development. Cofan

leaders plan to work with their communities and document the destruction caused

by oil development. Also they planned to work with their communities to

organize against further environmental destruction by the oil companies. This

grant will also cover for legal costs to demarcate the Cofan community lands.

In the next section of this term paper, I will be discussing a subject relating

to the rainforest called habitat fragmentation.

Fragmentation of a habitat, by its very nature, reduces the total amount of

area of the original habitat type. Two researchers, Ann Keller and John

Anderson suggest that the absolute habitat loss of pristine habitat and the

reduced density of resources associated with fragmentation potentially impacts

the biota (the plant and animal life of a region) more than any single factor.

Habitat fragmentation affects the flora and fauna (plants and animals) of a

given ecosystem by replacing a naturally occurring ecosystem with a

human-dominated landscape which may be inhospitable to a certain number of the

original species. However, in direct contrast to the ocean as a geographic

barrier, the human landscape matrix is typically accessible to plants and

animals, in that they are able to easily disperse across it, if not reside in

it.

On the other hand, the human landscape may directly contribute to the

extinction of species by slanting the ecosystem balance of species which are

highly adaptable to changing conditions. For example, the increased amount of

human-dominated landscape allows certain species to grow phenomenally, which

can result in harm to species which rely exclusively on very scarce areas . A

commonly referred to example of this is a bird called the brown-headed

cowbird. This bird is best characterized as a ?nest parasite? because it

because it replaces the eggs of another species with eggs of their own ,

allowing the other species to incubate and raise their young. Their increased

numbers have had negative effects on the reproductive successfulness of many

forest-dwelling birds.

In addition to titling the ecosystem balance in favor of species which are

highly adaptable, the loss of habitat associated with habitat fragmentation may

simply cause the other, less adaptable species rates to decline. A man named

James Saunders documents one remarkable example of how changing large expansive

areas of the birds of the wheatbelt of western Australlia as a result of

fragmentation. He showed that 41% of the birds native to the region have

decreased in range or abundance since the 1900?s and indicated that almost all

of these changes resulted directly from habitat fragmentation and the decline

in abundance of native vegetation. Although some species have increased in

abundance, he noted that many more species have been adversely affected than

have benefited.

Importantly, the species that typically increase in abundance or range when

habit fragmentation occurs are those which are adapted for being adaptable. In

other words, their resource needs can be met by a variety of conditions, and

thus often by human activities by reducing their competition with other

species. Because of this, these species which benefit by human activities are

not the ones we need to manage for and protect. Instead, we need to protect

those species which are adapted solely for survival in the rapidly disappearing

unfragmented habitat.

Besides physically changing a part of the original habitat, decreasing the size

of the original habitat can reduce the biological diversity of an area in

several ways. Reducing biodiversity of an area may occur if habitat fragments

are smaller than the home range of the animal with the largest home range that

existed within the intact ecosystem. Many birds have large home ranges because

they require patchily distributed resources. For example, one breeding pair

of ivory billed woodpeckers require five to six square miles of undisturbed

contiguous bottomland forest, and a single European goshawk requires twenty to

forty-five miles for his home range.

If a habitat fragment exists that is smaller than the minimum area required by

a given species, individuals of that species will not likely be found within

that habitat fragment. For example, the Louisiana waterthrush is rarely found

in small woodlots because they require open water within their home range, and

most small woodlots do not have year-round streams or ponds. If a species

requires two or more habitat types, they are often susceptible to local

extinction due to habitat fragmentation, because often they are unable to

freely move between the different habitat types. The blue-grey gnathatcher

moves from decidous woodland to chapparral (a warm area) during the breeding

season, and if one of the two habitat types can not be readily accesed, they

are very susceptable to local extinction.

Loss of any species from a community may have secondary effects that revrberate

throughout the ecosystem. For example, loss of a top predator from an area

because the fragment is too small can cause numbers of small omnivores to

increase, which in turn may cause excessive predation pressureon songbird eggs

and hatchlings, ultimately resulting in reproductive sucess.

Tropical communities are oftem more susceptable to loss of biological diversity

than temperate communuities, because tropical species typically are found in

lower densities, are less widely distributed, and often have weaker dispersal

capabilities. Many tropical species have evolved in that they have changed

their roles that they play in the rainforest. An example of this occurance is

the cassowary, an Austrailan rainforest frugivore, (or an animal that primarily

feeds on fruit) is extremely susceptable to local extinction by habitat

fragmentation because its habitat requirement of large coniguous rainforest

areas is compounded by its unique plant-seed despersal evolvment. This large,

flightless bird wanders nomadically in search of very large seeds, many of

which need to be digested before they will germanate. You?lll rember that

earlier another example of this situation in which the dodo bird became

extinct. The dodo bird digested seeds of the calvaria tree. But when the dodo

bird became extinct due to overhunting by humans, the calvaria tree, which made

the seeds to be digested by the dodo bird to sprout it?s plants started not to

sprout seeds. In the Rainforests, their are many such instances like this.

But unfortunately, many of them go unnoticed and thus, each day many of the

rainforest plants and animals go extinct.

Besides being home to extinction-prone species, tropical communities are prone

to destruction and fragmentation because of their physical location,

overlapping with the geographical birders of the third world nations. In

these nations, citizens often rely on the revenues raised from rainforest

timber or cattle raised on cleared land for survival. This constant pressure

on rainforest communities leads to excessive habitat fragmentation. Small

isolated fragments result, leading to an altered ecosystem balance. On the

tropical island of Java, where almost all of the original habitat remaining

exists in reserves, a group of ecologists have assessed the status of all of

the birds of prey found in the rainforest habitat. Nearly all the raptors were

extremely rare outside the reserves, as expected. They also found that the

larger the reserve was, the denser the birds populations were within the

reserve.

Interestingly, a scientist named Lovejoy (I couldn?t find his first name) in

1986 found a similar phenomena with Amazonian birds in the Biological Dynamics

of forest project (BDFF) in Brazil. The primary goal of the project is to

discover how rainforest communities respond after an intact ecosystem is split

into different size fragments. They found a crowding effect, in which the

abundance of birds in a forest fragment increased significantly directly after

deforestation of the adjacent area. The increased number of birds was

attributed to the migration of birds from the newly clear-cut area to the

forest fragment. This crowding effect decreased with increasing size of a

forest fragment.

Both tropical and temperate communities, however, are prone to the same

problems of inbreeding and loss of genetic variability, which results from

isolating subpopulations of plants and animals from each other due to habitat

fragmentation. If too large a distance exists between two fragments and a

species are unable to disperse across the area in between, the population is

essentially divided. Inbreeding may result if the subpopulation in a given

fragment is small. This has not been directly documented, but it is possible.

Size of a fragment and the amount of edge are inextricably linked. Abrupt

edges often results form fragmenting and ecosystem, in contrast to the more

gradual natural ecotones. Edge positively impacts many species of plants and

animals, but as mentioned previously, the species which benefit typically are

those which do not require human protection and management because they can

easily meet their resource need outside of the intact ecosystem. The

scientists from the BDFF project point out one exception. Tamarins and

marmosets, both species in need of protection , flourish in small tropical

rainforest reserves because of the luxurian growth of early successional plant

species, and the lack of large predators which are unable to exist in the

smaller reserves. Certainly , a system of only small reserves would not

suffice to protect the genetic heritage of biological diversity in the tropical

rainforest, but a heterogeneous mosaic of large and small reserves may provide

the best alternative.

Although edge has typically been associated with an increase in species

richness, researchers are increasingly documenting how edge effects negatively

impact the native plants and animals. The BDFF researchers pointed out that

although the number of species may be higher in edge that the adjacent interior

habitat, species diversity is usually not. Diversity takes into account not

only raw number of species, but the relative abundance of the species present.

Another potentially adverse effect of edge is that it inherently reduces the

size of the habitat interior because of the many physical changes which occur

where and edge is compared to a human dominated area. Most documented cases of

edge effects are from forest edges, so I will focus on them. In addition to

the luxuriant growth of shade-intolerant vegetation at a forest edge in

response to the increase in available light, a ?seed rain? bombards the forest

interior, often from introduced exotics. The increased exposure to wind causes

a higher rate of treefalls and tree mortality, and temperature and humidity are

quite different at the edge than in the forest interior. These physical

changes affect the plants and animals of the habitat. Lovejoy and others, in

the BDFF project in Brazil, found that the understory birds tend to avoid

artificial edges. They found 38% fewer birds 10 meters from clearing than 50

meters into the forest, and 60% fewer birds 10 meters from a clearing than 1 km

into undisturbed forest. An interesting item is that they did not find a lower

abundance of birds around natural edges, such as interior treefall gaps.

Several authors that I have read have suggested that the abundance of birds

decreases near an artificial edge due to decreased Nest success. Nest success

near edge decreased because of the increase in generalist predators and brood

parasites. As mentioned earlier, populations of brown-headed cowbirds, a brood

parasite, have increased tremendously as a direct result of human activity,

these birds have a negative impact on the nesting success of forest songbirds

that nest near the forest edge. Studies show that while vegetational changes

may extend from 300-600 meters into a fragment. This makes sense when one

considers that although generalist predators such as raccoons, cowbirds, and

chipmunks may concentrate their activity near the edge, they certainly also can

frequent the forest interior, often to the damage of those species which rely

exclusively on forest interior.

To reduce how far edge effects penetrate into a natural habitat, a biologist

Bernard Harris, proposed a system of long-rotation islands, in which and

old-growth center is surrounded by various age stands of timber. This system

provides some edge for those species which benefit from it, while minimizing

the amount of edge between the old-growth center stand and the surrounding

stands.

Now, to the final section of this term paper, the role that environmentalists

play and some of the reasons that they are trying to save it.

Rainforests cover less that two percent of the Earth?s surface, yet they are

home to some 40 to 50 percent of all life forms on our planet, as many as 30

million species of plants, animals, and insects. The Rainforests are quite

simply, the richest, oldest, most productive, and most complex ecosystems on

Earth. As biologist Norman Meyers notes, ?Rainforests are the finest

celebration of nature as ever known on the planet, and never before h