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Forests have probably been subject to anthropogenic destruction, or deforestation, since the earliest
days of Homo Sapiens and its predecessor species. The initial needs for fuelwood and construction
materials continued to increase as populations expanded and as industrial construction, discovery of
mineral resources in the forested areas, and eventually roadways and highways, and new and
successively larger settlements increased the demands for forest products.
Of all the anthropogenic impacts on ecosystems, perhaps few are as awesome and on grand scale as the
major and systematic destruction of large sized ecosystems as, forestsboreal, temperate, and tropical-
and grasslands. Boreal and temperate forest have been subject to acid precipitation/rain, largely a
consequence of industrial activity ; tropical forests have been subject to clearing for agricultural and
urban/suburban development; and grasslands have been subject to desertification, the shift of desert-
like conditions resulting from human misuse of the land.

Forest fires
The full benefits of forest resources can be obtained only if timber is protected from fires, diseases, and
insect pests. Fire is a great threat to forests, but it is also a natural feature of all but the wettest forests.
Natural fires are an important way for old trees and undergrowth to be cleared to make way for new
growth. Modern forestry practice therefore attempts to control fires rather than eliminate them.
However, the largest number of forest fires are caused by people or are of anthropogenic cause. They
may start many fires by carelessly dropping lighted cigarettes, or by leaving behind glass bottles, which
can act as a burning glass. Other forest fires are set deliberately. Forest fires could best be prevented
by educating people to understand the value of forests and the importance of protecting them.

Diseases and pests
Most trees diseases are caused by fungus infections. Diseases attack trees chiefly by clogging the flow
of sap, killing the leaves, or rotting the roots or wood. Some of the most destructive diseases include
beech bark disease, chestnut blight, Dutch elm disease, oak wilt, and stem blister rusts that affect pine

Floods and soil erosion
The roots of a tree make gaps in the soil so that when it rains the water can sink in before being
absorbed by the soil. These spaces also allow air and water to reach the roots of the plants.
When trees removed using heavy machinery, the soil is pushed down and the gaps fill in.
Because all plants and trees need that water and air to reach roots, the conditions become
unfriendly for new growth.
Because the soil no longer can absorb the water, when it rains the water remains on the top of
the soil and this can result in floods. The moving water also can completely wash away the top
layer of the soil. This is called soil erosion. Without the top layer of soil, which is full nutrition,
plants are not fed and find it hard to grow.
What we lose: About 24 billion tons of agricultural topsoil (the top layer of soil) wash or blow
away each year.
Forests help produce rainfall. The more trees, the more water gets absorbed into clouds and
the more rain falls. If the forests disappear, there will be less rain resulting in dryer conditions
that eventually lead to drought. Once this happens, the damage is extensive making it difficult
to plant more trees or plants later because the soil is so hard and dry.
Greenhouse gases and acid rain
The earth's atmosphere contains a number of greenhouse gases. Greenhouse gases trap the
heat from the sun inside the atmosphere. Some greenhouse gases are carbon dioxide (CO2),
methane and water vapour. We need these gases in small amounts, but they can be harmful at
high levels.
Forests help remove large amounts of CO2 from the air. They absorb the gas
during photosynthesis. However, more CO2 is produced than all the trees can absorb when
fossil fuels are burned, for example and when forests are cut down, even less CO2 is being
absorbed leaving it trapped in the atmosphere.
As greenhouse gases build up, more of the suns heat gets trapped and that can lead to climate
change (the disruption of the delicate balance of the earth's ecosystems). The added pollution
in the atmosphere can also lead to acid rain when the gases mix with water in clouds. When
this is deposited on forests it can damage the trees and the ecosystem as a whole.
Species extinction
Another harmful result of deforestation is the extinction of animal and plant species. They
disappear because their environment and life cycles have been disturbed and they are unable
to adapt to the changes. When species disappear, it is called extinction. Essential habitat is lost
when forests are cut down; wildlife species lose their homes, their food sources and their place
in the web of life. Even though extinction is part of life, it is happening far too quickly now.
It is estimated that as many as 150-200 species around the world go extinct every day!

Causes and Motives for/behind Deforestation
According to The World Rainforest Movement , Among the direct causes of deforestation,
some of the main ones are: the substitution of forests by other activities (agriculture, cattle-
raising, tree plantations, shrimp farming, etc.), logging, mining, oil exploitation, and construction
of large hydroelectric dams (which result in the flooding of extensive areas of forest).
Forests are cleared for agriculture. The deforestation rate in Amazon rainforest, the worlds
largest jungle, jumped 40 percent in the 12 months to the middle of 2002. The Amazon is an area
of continuous tropical forest just under half the size of the continental United States, and has
been described as the lungs of the world because of its vast capacity to produce oxygen. It is
also home to up to 30 percent of the planets animal and plant species.
The primary driving force behind the destruction of the rainforests is livestock grazing. Beef
exporting from Brazil has increased more than fivefold in the last six years. World
Watch magazine, in the article, Eating Beef says that From now on, the question of whether
we get our protein from animals or plants has direct implications for how much more of the
worlds remaining forest we have to raze.
Forests are destroyed by inequitable land policies. International finance institutions require
countries to increase exports in order to keep up with their loan payments, and clear-cutting the
forests for crops is often their only option. The agricultural land of peasants is taken over to
increase exports, forcing them to migrate into the forests where they cut and burn the forest in
order to survive. In many cases, governments promote migration to expand the agricultural
frontier and allow for more farm exports.
Global warming threatens forests worldwide. Deforestation contributes to global warming, but,
in turn, global warming will increase the loss of forests. M any of the world's forests are in poor
condition, fragmented, and depredated, and so they are less able to adapt or adjust to climate
change. As the global climate warms up, patterns of rainfall will change; and 'normal'
temperature patterns will be disrupted. The expected rate of global warming and sea-level rise
will be too fast to allow most forests to be able to adapt quickly enough to survive.

The organization, American Forests, reports that the U.S. could offset 20 to 40 percent of its
carbon dioxide emissions by increasing carbon storage by 300-600 million tons per year. This
would require a comprehensive plan to plant trees, improved forest management practices, and
alternatives to wood and biomass fuels
Each year, forest fires, burn between 6 and 14 million hectares of forest. A major cause of the
loss and degradation of forested land comes from fire. The area lost to fire is roughly equal to
that caused by destructive logging and conversion to agriculture combined. Severe forest fires,
such as those in Indonesia in 1997/1998 and in Australia in 2001/2002, bring enormous and in
some cases life-threatening levels of pollutants. Governments rarely address the underlying
causes of forest fires. Instead of prevention efforts, they just work to put the fires out. Working
on prevention will become essential because global warming will increase the number of forest
Forests are harmed by the trade in illegal extracted timber. Legal supplies of wood fiber fall
accounting for almost 70 percent of wood supply, meaning that illegal logging exceeds the
volume of legal logging. All told, illegal logging alone has destroyed 10 million hectares of
Indonesia's rich forests, an area the size of Virginia.
It is important to use only wood certified by the Forest Stewardship Council (FSC)--the only
label recognized as providing "ecologically-sound" timber. Worldwide, FSC-accrediting bodies
have certified about 24 million hectares of forests in 45 countries. When consumers demand
certified wood, non-certified sellers will have difficulty competing, and illegal logging becomes
more difficult. This certification stamp means the wood is from well-managed and
environmentally sensitive logging operations. It also assures that the wood is not the result of
monoculture plantations, clear-cutting, violations of indigenous land claims, or other
environmental hazards. Due to these other considerations, relying on wood labeled "second-
growth" is not enough. The FSC label is the only guarantee that the wood purchased is
environmentally sound. Currently only a small portion of the U.S. lumber market, FSC wood is
growing in popularity in other areas, especially in Europe.
Building large hydroelectric dams destroys forests. Forests are lost when farmers, displaced by
dams being built, are forced to move and clear forests in other areas in order to grow their crops.
Dams also require road building, allowing access to previously remote areas by loggers and
"developers," causing even more deforestation.
Forests are cleared for fuel or export. Crucial to slowing the loss of the world's natural forests is
finding alternative sources of energy for low-income countries so that wood is not burned for
Consequences of Deforestation
Removing forests (and their natural functions) causes many serious problems.
Loss of trees makes global warming worse. Through photosynthesis, trees remove carbon
dioxide from the air, produce oxygen, and store carbon as wood. One ton of carbon in wood or
forest biomass represents 3.67 tons of atmospheric carbon dioxide recycled. We are creating
warming, not only by putting more CO2 into the air, but also by getting rid of trees that absorb
and remove carbon from the air.
I mpact on Ecosystems. Forests preserve water, soils, plants and wildlife. Their destruction
aggravates droughts, soil erosion, and pollution of watercourses, and causes extensive flooding,
and increased pest populations due to the ecological imbalance.
Loss of Species. Tropical forests contain at least half the Earth's species, so their loss causes a
dramatic loss of biodiversity. Clearing and destructive logging of forests is the single greatest
cause of species extinction worldwide.
Harm to Water. Forests are natural dams that catch rainwater in their canopies and in leaves and
litter on the forest floor, retaining and purifying rainwater. Forest logging allows rapid run-off
and destroys the ability of the soil to absorb water.
Policies Needed to Halt Deforestation
Despite the creation of new organizations to promote sustainable forestry, and continuing efforts
of major international conservation organizations, the rate of forest loss accelerated through the
1990s. In "Requiem for Nature," John Terborgh, says
Deforestation is driven by a wide range of social and economic forces, but underlying them all is
the relentless march of human population growth and the exponentially rising demand for land
and forest products such growth generates. These demands are not going to slacken in the
decades ahead; indeed, they will only expand. Slowing down tropical deforestation, much less
halting it will therefore entail bucking powerful and inexorably growing forces. It is in this stark
light that the prospects for conserving tropical forests must be considered.
If we do not soon change public policy regarding tropical forests, the primary forest will
probably be gone sometime before 2045
Effect on global climate
net impact on atmospheric carbon dioxide levels, though they may have other climatic effects
(on cloud formation, for example, by recycling water vapor). No rainforest today can be
considered to be undisturbed. Human induced deforestation plays a significant role in causing
rainforests to release carbon dioxide, as do other factors, whether human-induced or natural,
which result in tree death, such as burning and drought. Some climate models operating with
forest dieback and the subsequent release more carbon dioxide. Five million years from now, the
Amazon rainforest may long since have dried and transformed itself into savannah, killing itself
in the progress (changes such as this may happen even if all human deforestation activity ceases
overnight). The descendants of our known animals may adapt to the dry savannah of the former
Amazonian rainforest and thrive in the new, warmer temperatures.