Deforestation-Killer of the Earth
Why is it happening? What are the consequences?
Deforestation refers to the massive-scale cleaning of forested land. Governments nowadays are particularly devoted to constructing roads that lead into the remote and untapped lands in search of some more natural resources. As a result, more and more forests that were previously inaccessible are getting deprived of their trees, and the negative impacts of deforestation are becoming increasingly evident.
Before explaining the exact “negative impacts” that deforestation causes, this course would first answer the question in most readers’ minds: Why is deforestation happening? Why can’t humans stop cutting away forests? The answer to this question is rather simple: humans cut trees because they need more land, more crops, and more fuel. When a local community has used up all the empty land around them but still wants to construct new buildings or farms, they usually choose to cut down all the trees from nearby forests to gain a new piece of empty land so they can build all the new stuff they want. People may also conduct deforestation just for the wood that they can collect by cutting down trees. Wood is useful as a construction material and as a fuel. People use wood to construct wooden houses and burn them to gain warmth. Cutting all the trees down from a forest, therefore, allows people to bring those wood into their homes, factories, or construction sites, where they can make good use of the material. People may also conduct deforestation for the act of deforestation itself. There is a popular technique to enhance crop growth in agriculture: the slash and burn technique. This technique is all about burning large areas of forested land so that the ashes left on the ground can fertilize the soil for future crops that are planted on that land. However, the fertile land attained by adding the ashes of trees to the soil will only remain fertile for a few years, and after the soil gets back to its infertile state the farmers will have to go to some other place in order to burn new forests and gain new areas of fertile fields. Overall, people conduct deforestation to get more land, collect more wood, and produce ashes that would make the soil fertile for future crops planted in the area.
Despite the numerous goods deforestation can do for humans, deforestation has many negative impacts.
Firstly, deforestation causes a loss in biodiversity. 80% of the Earth’s animal and plant population lives in forests, and forests are composed of trees. Trees have crucial roles in a forest. They help balance the temperature in the forest, thus preventing the temperature difference between the night and the day from being too large. They also provide shelter and shade for animals and small plants, protecting them from bad weather and predators. Finally, the leaves and fruits of trees can be food for some animals. Therefore, removing trees from a forest is equal to drastically changing the habitat of the significant amount of animals living in the forest, and lowering their chances of survival now that they are in an environment they are not adapted to. Many plants and animals die can die after their habitat has been deforested. Entire species which have all populations living in a particular forest can be wiped out. These wiped-out species would be missing from the complicated forest food chain, and further, affect the survival of other species in the forest ecosystem. All these consequences lead to a reduction in biodiversity.
Secondly, deforestation leads to food shortages.
The first way deforestation can lead to food shortages is by causing a reduction in local humidity and rainfall. When trees are present, their roots absorb the water in the soil. The trees drink water by letting the water enters through roots, get transported through the entire tree, and arrive at the leaves on the top. When the “holes”—stomata—at the bottom of the leaves open, the water that got to the leaves will evaporate through these holes and join the atmosphere as water vapor. When the concentration of water vapor in the atmosphere reached a certain point, the water vapor in the sky would condense into raindrops and fall down to the ground, getting absorbed by the soil again. If all the trees are taken away in deforestation, there will be no way for the water deep down in the soil to evaporate and get transported into the atmosphere again. Instead, the water that remains in the soil would become water runoff, flow towards adjacent rivers, and end up leaving the region and heading for the sea. The repetition of such a process—rainwater leaving the region and heading towards the ocean—will gradually make the region arid and dry, as its only “income” of water—the rainwater—is now all flowing away and not getting returned to the atmosphere in order to get rained down to supply the region with water again in another storm. With the climate of the region being changed after its forests have been removed, the crops that were planted later to replace the trees would have to tolerate an arid climate unsuitable for their growth. This leads to food shortages, as the crops later planted in this area will give unimpressive harvests.
Thirdly, deforestation leads to soil erosion. Tree roots have a strong strength and could hold the soil beneath them firmly in place. When tree roots are replaced with shorter and weaker crop roots, the soil beneath the crops will be more loosely held, meaning that they can get easily “brought away” by floods or rainfall. This means that mudslides will happen more frequently. The soil, carried by water, will flow down rivers and streams, damaging animal habitats in these water bodies and hydroelectric structures downstream that are built by humans.
Fourthly, deforestation leads to climate change. Trees can store carbon(as glucose), and that makes them a key stage of the carbon cycle. The carbon cycle is composed of the atmosphere and several other carbon sinks(places or objects that can store carbon) all around Earth, one of the carbon sinks being the trees on planet Earth. The trees on Earth store some carbon in them temporarily so the amount of carbon in the atmosphere wouldn’t be as much. If the amount of carbon in the atmosphere increases too much, then the Earth would be heated up and become unsuitable for living. (To know the exact reason why an increase in the carbon concentration in the atmosphere would cause the Earth to heat up, please visit the course “Greenhouse gases-The chosen ones”!) Therefore, cutting trees down in deforestation is equal to reducing the total volume of carbon the plants on Earth can store for the atmosphere. The surplus carbon, those that got nowhere to go after large amounts of trees have been cut down, will join the atmosphere instead. Then, as the carbon concentration in the atmosphere increases, the global temperature would increase too, causing climate change.
The second way deforestation can lead to food shortages is by making the soil(that the trees were previously planted on) lose its fertility. By removing trees from the soil they previously grew on, people are turning the soil beneath over and over, which breaks all the pores and earth wormholes inside the soil. These pores are openings for fresh air and water to enter the deep soil and nourish the roots of the trees that were previously planted here. Now that these pores are destroyed and filled up with soil, it is hard for air and water to reach down deep into the soil and feed the roots of the crops that replace the trees in their patch of land. Also, with the use of shovels and other sharp tools in the process of trying to unearth the remaining roots of the trees, workers easily break the pieces of organic matter and large soil particles into smaller fragments. This means that later when the uprooting of all the trees is done, the remaining soil particles will be a lot smaller(on average) than before. This results in the soil layers becoming more compact and tight(as finer particles can be compressed tightly together), thus letting even less air and water enter the deep soil to nourish the roots of the plants planted here later. These soil are now infertile—incapable of supporting the well-growth of the plants that are planted in them. Crops will grow in poor conditions of limited air and water, resulting in few harvests.
You might be wondering why would the cutting of some trees lead to an overall, dramatic increase in the temperature of the planet. Of course, the cutting of a few trees would not cause an increase in the global temperature. However, as deforestation has been becoming increasingly common in recent years and large amounts of trees have already been cut down, the act of deforestation has started to show an impact on the global climate. You might also be wondering that, since people usually replace cut-down trees with newly grown crops, those crops can help substitute the trees in their job of storing carbon for the atmosphere. Unfortunately, despite the fact that crops—like all plants—can store carbon, they store a lot less than trees do. This means that by replacing trees with crops, people are still reducing the total volume of carbon Earth’s plants can store.]
Lastly, deforestation can cause desertification and droughts in the area where trees have been removed. The presence of trees not only increases the amount of rainfall in an area but also improves the soil quality of that area so the soil can hold more water. When trees are present, dead plant substances—leaves and branches—fall down from them, and get decomposed by microorganisms. The decomposed substances would nourish the soil below and increase the soil’s capacity for holding water. However, when a forest is replaced with crops or left barren, fewer dead plant substances would fall to the ground to nourish the soil. Crops will not have dead plant substances falling from them because of two reasons: crops are small and short so their leaves and structures won’t be blown down by the wind, and that crops are yielded by farmers normally within a year of their plantation, leaving them no chance to wilt and fall onto the ground. If the forest is left barren to save space for the later construction of buildings, no dead plant substances would fall onto the soil too, as there are no plants left at the site now! The lack of dead plant substances to improve the soil’s capacity for holding water combined with the reduction in rainfall caused by the absence of trees means that the soil and climate in the area where the trees have been removed will become especially dry, leading to droughts and even desertification.
In this course, we have talked about what deforestation is, why deforestation is happening, and the consequences of deforestation. As city or suburb dwellers that are distant from those forests that are being massively cut down right now—the Amazon, for example—we might feel too distant from the issue of deforestation. However, if we move ourselves to do one simple thing—share this webpage for example—then we are doing what we can to help solve the deforestation issue. If you are feeling worried about the Earth and the deforestation issue after reading this article, please hang on to Earth Academy’s updates, as in the next course we will be sharing some solutions for the deforestation problem!
Citations:
Geographic, National. “Deforestation.” National Geographic Society, 16 July 2022, https://education.nationalgeographic.org/resource/deforestation/.
Tazeen, Taufiya. “Deforestation: Definition, Causes, and Consequences.” Embibe Exams, 29 Aug. 2022, https://www.embibe.com/exams/consequences-of-deforestation/.
Butler, Rhett A. “The Impact of Deforestation.” Mongabay, Mongabay, 16 Apr. 2020, https://rainforests.mongabay.com/09-consequences-of-deforestation.html#:~:text=Consequences%20of%20Deforestation%201%20Local%20and%20regional%20consequences,extinction%20of%20species%20that%20provide%20Earth%20with%20biodiversity.