acting as the home of flora and fauna, forest acts as a carbon sink by
absorbing a lot of carbon dioxide during photosynthesis. Thus, the harmful
greenhouse gases that cause global warming will be absorbed by the trees.
Indirectly, the air will be fresh and the temperature of the Earth will be low
as the trees in the forest produce oxygen during photosynthesis. In other
words, the forest also acts as the green lung to filter the air and provides
oxygen to all living things for respiration.
forest acts as water catchment areas. This is because forest contains area to
collect water which then runs into the reservoir. In fact, most of the rainwater
will enter the reservoir. In addition, trees decrease the water-related risks
or disaster such as landslides, floods, and droughts and help prevent
desertification. The trees also prevent soil erosion as the roots will grip the
as the forest contains many species of plants and animals, the forest can
provide food and medicine to humans. In fact, about 25 percent of cancer
fighting organism are found in the Amazon. Forest also provides timber for
humans to make wooden furniture and papers. Indirectly, it provides jobs such
as forest management and timber production for humans. Forest is also one of
the destinations in ecotourism such as Forest Research Institute Malaysia
(FRIM), Selangor, and Taman Negara in Pahang, Kelantan, and Terengganu. These
tourist destinations contribute to the source of income for Malaysia.
Since forest is so important to
humans’ life, why we need to cut them down? One of the main reasons is to find
land for agriculture. Farmers will cut down the forest to have room for their
crops to grow. The slash-and-burn agriculture method is used to clear off the
forest by cutting down the trees and burn them off. Then, the crops are planted
in that area. This method is highly efficient as the weeds can be removed quickly
and the ashes can use to nourish the land. However, after few years, the soil
becomes infertile and the weeds start to reappear, the farmer will find a new
patch of land and the process starts all over again and again.
also need more room for cattle ranching. All of these happened because the
population of humans is kept on rising and there isn’t enough food for the
growing population of humans.
growing population of humans means they need more house and place to live.
Thus, humans cut down the forest to find space for housing and urbanization. For
example, in Penang, about 16 roadside trees in the Green Land were cut down
just to widen the road for the convenience of the residents. However, based on
the reporters the widening of the road would not solve the traffic problem in
the long run. Some of the residents had made a complaint about this issue, but
the related authorities just remained silent. Trees are cut down as well to obtain
timber to build houses, make wooden furniture and charcoal. Worst still, some
of the loggers act illegally, causing the logging process uncontrollable and
leading to further destruction of the forest.
cut down trees to make papers and draw a poster about ‘Save the Trees’. Isn’t
that ironic? One of the factors of deforestation is just simply to make papers
for books, exams’ question papers, newspapers, assignments’ papers and more.
Country such as America, China, Japan, and Canada can produce more than the
world’s paper production which is about 400 million tons a year. However, based
on the research done by the Environment Paper Network, about 640 million trees
represent as papers are being thrown away each year without recycling it.
deforestation even occurs intentionally. Some of it is caused by a combination
of human and natural factors such as wildfires during hot and sunny days. Some
herbivores which keep on grazing on the young trees also prevent them to grow.
Thus, the expansion of the forest is inhibited.
Deforestation causes negative
impacts on the environment. One of the main effects is the loss of biodiversity
and valuables medicines. This is because the destruction of trees in the forest
causes loss of habitats for many species of flora and fauna. This may lead to
the extinction of certain endangered species. In fact, it is estimated that
more than 28,000 species will become extinct by the next quarter of the century
due to deforestation. For example, Bali Tiger which live in Bali Island,
Indonesia was officially declared extinct by the IUCN in 2008. The last
documented sighting of this Bali Tiger was in September 1937. However, that
female adult Bali Tiger was killed in West Bali. The main reason for the
extinction of Bali Tiger is deforestation as the Tigers lost their homes,
wandered around to find food at the nearby village and got themselves killed by
the native as the Tiger is a threat to them.
Since forest is destroyed, the number of
trees also decreases. This leads to the next problem that is greenhouse effect
and global warming. As the number of trees decreases, the rate of
photosynthesis also reduces. Thus, less carbon dioxide is used for
photosynthesis but more carbon dioxide is released due to the respiration of
living organism. As the level of carbon dioxide increase, the heat is trapped
by carbon dioxide in the atmosphere. As a result, climate changes such as
drought and floods occur.
Moreover, the use of slash-and-burn
agriculture method will release smoke particles, dust, and gases such as carbon
dioxide and carbon monoxide. This will cause air pollution as well as haze.
Since the rate of photosynthesis is low, the carbon dioxide will accumulate in
the atmosphere and increase the temperature of the Earth.
addition, without the grips of the roots of the trees, nothing will bind the
soil particles together. The soil structure becomes unstable. During heavy
rains, the top layer of the soil disintegrates. The eroded soil carried by the
rainwater flows into the river. The soil will deposit in the river and cause
water blockage. Some of the soil will also deposit in the bed of the water
catchment area and cause depletion of water catchment area in the forest. This
also can cause flash flood during rainy season. Normally, the erosion of soil
and landslides occurs on steep hill slopes. In extreme cases, the landslides
might endanger the safety of the nearby inhabitants. For instance, the mudslide
that happened in California in January 2018 had killed at least 20 people and
destroyed hundreds of houses. The tragedy happened because the wildfires in
December 2017 had cleared about 300,000 acres of land on the hills, making the
land more slippery and more prone to erosion than normal healthy land.
Furthermore, deforestation may lead
to the loss of nutrients in the soil. That means the fertility of the soil is
reduced. This is because when the leaf shed, the leaf litter will be decomposed
by fungi and bacteria on the forest floor to form humus. In fact, humus also
induced decomposed dead plants and animals, and animal waste which will help to
bind the soil and hold water. However, when the forest is removed, the soil is
exposed. Rainwater will wash away the topsoil which is high in nutrients easily
whereas wind will blow away the loose soil particle.
Last but not least, deforestation also
disrupts water cycle. Trees play an important role in water cycle by keeping
the balance between the water on the land and the water vaporized in the
atmosphere by the trees which carry out evapotranspiration. Evapotranspiration
is the combination of evaporation and transpiration. However, without trees,
the water balance is destroyed and resulted in a change of precipitation and
After realizing that deforestation
reduces biodiversity and destroys the Earth, humans start taking steps to undo
some of the damage they have done by conserving it. There are two types of
conservation that are in-situ conservation and ex-situ conservation.
In-situ conservation is the conservation of
species within their natural habitat. Humans will protect those endangered
species by protecting them from the predator (including humans) and their
habitat. This allows the species to grow, reproduce and evolve by itself.
Nonetheless, the conservation project is not aimed at few selected species but
the wildlife which lives in that area. National parks, sanctuaries, and
biosphere reserves are some of the examples of in-situ conservation.
Ex-situ conservation is the conservation of
species outside their natural habitat. A species is selected and a proper
shelter (artificial environment), food and care are given to that species so
that it can survive and flourish. This conserving method will be used if the
natural habitat of that species is not appropriate but the man-made environment
is more suitable for the growth of that species. And of course, the method is
used for research purposes to develop the gene banks, seed banks, and so on.
However, this method is a bit risky as a lot of effort and research about that
species need to be done to maintain the condition of the artificial shelter. If
anything goes wrong, they might lose that species. Zoo, aquarium, and botanic
garden are some of the examples of ex-situ conservation.
Ozone depletion is the thinning of
ozone layer whereby the layer of ozone in the stratosphere is being depleted. Firstly,
what is ozone layer? Ozone layer is a layer of high concentration of ozone (), located on the
Earth’s stratosphere about 17 and 25km above the surface of Earth. The ozone
layer acts like a protective layer to the Earth by absorbing ultraviolet (UV)
rays from the Sun. It will prevent excessive UV rays form reaching the Earth
and cause serious damage to the organism. It also traps some of the UV
radiation to keep the Earth warm and comfortable.
4.1 Causes of Ozone
main factor of ozone depletion is the use of chlorofluorocarbons (CFCs) which
is used as coolants in air conditioners and refrigerators; as propellants in
aerosol cans; as forming agents in the production of Styrofoam. Besides,
volatile organic compounds (VOCs), which are types of organic compounds that
easily being vaporized, are one of the causes of it. They contain chlorine and
bromine atoms on it which contribute to the thinning of the ozone layer. VOCs
can be released by burning fuel such as natural gas and gasoline from the
vehicular emission and waste gases from industrial process. Initially, humans
thought that the ‘ozone-depleting substances’ are environmentally friendly as
it is chemically inert. However, they are only stable at a lower atmospheric
region, but it will be exposed by UV rays and become highly reactive at the
stratosphere and react with the ozone molecules.
depletion also can cause by natural disaster that is volcano eruption. When the
volcano erupts, the massive cloud of ashes produced has a high concentration of
halogens such as bromines and chlorines. The volcanic smoke will drift up to
the stratosphere and stay there for 2 to 5 years. Thus, the halogens will
become reactive due to the UV rays from the Sun and react with the ozone to
become stable. For example, the eruption of Mount Pinatubo (Philippines) in
1991 had caused a huge impact on the ozone layer as the thick ashes had plumed
34km up into the stratosphere. However, humans still win this ‘Destroy the
Ozone Layer’ competition as they have contributed about 80 percent of ozone-depleting
substance to the stratosphere whereas Mother Nature only contributed the
remaining 20 percent.
the CFCs reach the stratosphere, ultraviolet (UV) light break down CFCs and
release chlorine atoms. The chlorine atoms will react with the ozone to form
chlorine monoxide. The chlorine monoxide combines with oxygen atoms to form
chlorine atoms again and oxygen molecules. The chlorine atom reacts with
another ozone molecule again. The process of breakdown of ozone is repeated. It
is estimated that one chlorine atom can break down about 100,000 ozone
molecules. Thus, the layer of ozone becomes thinner each year.