Introduction
Forests play a vital role in the planet’s global ecosystem, providing a home to many species and resources to people. About 30% of the Earth is currently covered by forests, although this number was initially higher by 10% (Nunez, 2019; Prevedello et al., 2019). From 1990 to 2016, approximately 500 thousand square miles of forest were lost due to intentional and accidental deforestation (Prevedello et al., 2019). One of the largest and most prominent forests on the planet – the Amazonian rainforest – diminished by 17% during the past 50 years due to human activity (Nunez, 2019). However, deforestation affects other regions, including Iran, Malaysia, China, Russia, the United States, Australia, and more (Gholoubi et al., 2019; Prevedello et al., 2019; Zemp et al., 2017). While this process leads to more available land for agriculture and settlement, it also negatively affects ecosystems. Research demonstrates that deforestation adversely impacts the environment, resulting in decreased biodiversity, increased greenhouse gas emissions, change in atmosphere and water chemistry, soil erosion, flooding, and climate change.
Consequences of Deforestation
The first potential outcome of deforestation is the loss of animal habitat and subsequent diminishing biodiversity. Despite covering less than half of the planet, forests are home to about 80% of all animals and plants (Nunez, 2019). In particular, tropical forests house two-thirds of all species, meaning that forests’ condition directly influences their survival (Giam, 2017). Increasing deforestation destroys the habitat of animals and plants, and the territory of the former forest is most often taken over by agriculture or manufacturing. This reduces the number of animals, such as the Malayan tiger, and leads to potential extinction (Giam, 2017). As a result of deforestation, many unique local species disappear, unable to find a new place to settle.
Biodiversity loss in tropical forests is an especially pressing problem, as it is one of the central regions for agriculture development. According to Symes et al. (2018), 89% of the investigated bird species experienced some loss of habitat between 2000 and 2015 in tropical areas (p. 1). The scholars also find that more than half of the species are at risk of being lost due to deforestation and exploitation (Symes et al., 2018). These numbers suggest that if the acceleration of deforestation for manufacturing continues, the world may lose hundreds of species in the following decades.
Apart from affecting the planet’s biodiversity, deforestation also directly influences the chemistry of and water concentration in the atmosphere. Notably, deforestation drives the rate of greenhouse emissions up in two ways. First, as trees absorb carbon dioxide from the air to produce oxygen, their removal decreases this exchange and leads to less carbon dioxide being engaged in the process of photosynthesis (Kumari et al., 2019). Thus, forestation is directly responsible for keeping the balance of oxygen production and the air quality of the planet.
Second, it has been shown that the process of felling trees leads to them releasing the captured carbon dioxide back into the atmosphere, which eliminates all potential benefits of forestation in this area (Nunez, 2019). As Pendrill et al. (2019) note, deforestation is considered to be the “second largest source of anthropogenic greenhouse gas emissions,” the first being agriculture (p. 1). The sum of these two activities increases the release of greenhouse gases, which, in turn, affects the air quality and the climate. It should be noted that the temperatures are influenced both locally in deforested areas and globally (Wan Mohd Jaafar et al., 2020). Thus, deforestation not only reduces the number of trees that could potentially lower the volume of greenhouse gasses, it greatly contributes to air pollution.
The removal of trees on a massive scale disrupts the water cycle, which leads to soil erosion and change in water chemistry. According to Kumari et al. (2019), the water cycle greatly depends on the process of evapotranspiration, which is regulated in large part by forestation. If the cover of forestation is lost, the watershed directly affects the soil, leading to erosion and increasing the risk of flooding (Kumari et al., 2019). Additionally, deforestation also has been proven to change the rainy season onset in Amazonia (Leite‐Filho et al., 2019). The lack of trees resulted in a delayed start of rainy days and increased dry spells duration, where nature and people living in or near Amazonian forests experience prolonged droughts. Thus, one can see that deforestation destabilizes the water cycle in two opposing ways, causing unbalanced water levels both in areas where water needs to be controlled to avoid flooding and where the soil dries out significantly due to the lack of rainfall.
Subsequently, the soil in deforested areas slowly changes its chemistry and the chemistry of the surrounding water. Gholoubi et al. (2019) show that the risk of toxicity (in particular, with metals such as aluminum) increases as a consequence of deforestation. The soil loses enriching elements, such as calcium, potassium, and sodium, while the presence of metals increases (Gholoubi et al., 2019). As the main reason for deforestation is agriculture, the soil needed for producing crops becomes unusable due to the lack of proper replenishment supported by trees and an active balanced ecosystem. If the farmers leave the unusable deforested land, it becomes susceptible to flooding, which also changes the chemistry of water and further destroys the local environment.
As trees engage in the water cycle and carbon dioxide capture, they also influence the temperature locally and globally. Winckler et al. (2019) describe several processes that allow forests to regulate temperatures in colder and warmer regions – surface albedo and evapotranspiration. First, albedo is the measure that indicates the level of sunlight that the surface reflects, where higher reflection leads to cooler temperatures. In lower altitudes, the albedo changes in deforested areas lead to the surface not reflecting the sunlight, which leads to rising temperatures (Winckler et al., 2019). Prevedello et al. (2019) suggest that the process of deforestation and subsequent changing albedo may result in the planet heating up by 1.45C by 2050 (p. e0213368[1]). While this number does not appear high, it may lead to substantial changes in climate, including an increased risk of flooding, forest fires, and other natural disasters (Kumari et al., 2019). The issue of global warming, otherwise termed climate change, is directly related to deforestation.
Opposing Arguments
The negative consequences of deforestation are well-documented in recent research. However, one may argue that deforestation also has benefits that make the sacrifice of some forestation necessary. For example, as the land previously occupied by forests is used for agriculture, one may state that it is vital to support both local and remote communities by providing resources and jobs (Kumari et al., 2019). Moreover, it is a process that results in territories that can be occupied by houses and other buildings, leading to the expansion of people’s communities. Deforestation is beneficial economically for developing and developed countries.
However, the short-term benefits of deforestation are unbalanced in comparison to its long-term influences on the planet. Kumari et al. (2019) and Nunez (2019) point out that deforestation has consequences that bring more negative than positive outcomes to local communities, destroying habitats for animals and people. Flooding is a major example of how the destruction of forestation makes the environment dangerous. Moreover, much of the agriculture performed in deforested areas destroys the soil and water permanently or for long periods of time, implying unstable support for the local community. Finally, many indigenous peoples do not benefit from deforestation, especially in tropical areas. In contrast, they are often displaced from the lands taken over by manufacturing plants or communities traveling from other regions to participate in the land’s cultivation.
Second, one may point out some inconsistent or even positive outcomes of deforestation. Ilha et al. (2019) find that the fish population in waters by deforested areas increases, although biodiversity is unaffected. Nevertheless, the authors point out that their observations do not predict long-term outcomes. They only provide insight into fish populations, while other species’ well-being and preservation are not examined. The amount of research pointing out the negative consequences of deforestation, in contrast, cannot be ignored.
Conclusion
Deforestation continues to be a research problem due to the variety of impacts of this process on the planet’s ecosystem. An abundance of studies demonstrates that forestation is a vital element of the global environment, and its destruction leads to long-term disruptions on land and in the air. Deforestation results in the elimination of rare local species and the depletion of habitat for animals. Furthermore, it leads to the deterioration of soil quality, increasing the risk of both flooding and dry spells, depending on the initial area’s climate. The trees play an essential role in producing oxygen and capturing carbon dioxide, and their felling leads to air pollution and temperature increase. As a result, climate change and a variety of other negative consequences pose a risk to the global ecosystem.
References
Gholoubi, A., Emami, H., Alizadeh, A., & Azadi, R. (2019). Long term effects of deforestation on soil attributes: Case study, Northern Iran. Caspian Journal of Environmental Sciences, 17(1), 73-81.
Giam, X. (2017). Global biodiversity loss from tropical deforestation. Proceedings of the National Academy of Sciences, 114(23), 5775-5777.
Ilha, P., Rosso, S., & Schiesari, L. (2019). Effects of deforestation on headwater stream fish assemblages in the Upper Xingu River Basin, Southeastern Amazonia. Neotropical Ichthyology, 17(1), e180099[1]- e180099[12].
Kumari, R., Banerjee, A., Kumar, R., Kumar, A., Saikia, P., & Khan, M. L. (2019). Deforestation in India: Consequences and sustainable solutions. In M. N. Suratman et al. (Eds.), Forest Degradation Around the World (pp. 1-18). IntechOpen.
Leite‐Filho, A. T., de Sousa Pontes, V. Y., & Costa, M. H. (2019). Effects of deforestation on the onset of the rainy season and the duration of dry spells in southern Amazonia. Journal of Geophysical Research: Atmospheres, 124(10), 5268-5281.
Nunez, C. (2019). Deforestation explained. National Geographic.
Pendrill, F., Persson, U. M., Godar, J., Kastner, T., Moran, D., Schmidt, S., & Wood, R. (2019). Agricultural and forestry trade drives large share of tropical deforestation emissions. Global Environmental Change, 56, 1-10.
Prevedello, J. A., Winck, G. R., Weber, M. M., Nichols, E., & Sinervo, B. (2019). Impacts of forestation and deforestation on local temperature across the globe. PloS One, 14(3), e0213368[1]- e0213368[18].
Symes, W. S., Edwards, D. P., Miettinen, J., Rheindt, F. E., & Carrasco, L. R. (2018). Combined impacts of deforestation and wildlife trade on tropical biodiversity are severely underestimated. Nature Communications, 9(4052), 1-9.
Wan Mohd Jaafar, W. S., Abdul Maulud, K. N., Muhmad Kamarulzaman, A. M., Raihan, A., Md Sah, S., Ahmad, A., Saad, S. N. M., Mohd Azmi, A. T., Jusoh Syukri, N. K. A., & Razzaq Khan, W. (2020). The influence of deforestation on land surface temperature—A case study of Perak and Kedah, Malaysia. Forests, 11(6), 670.
Winckler, J., Reick, C. H., Luyssaert, S., Cescatti, A., Stoy, P. C., Lejeune, Q., Raddatz, T., Chlond, A., Heidkamp, M. & Pongratz, J. (2019). Different response of surface temperature and air temperature to deforestation in climate models. Earth System Dynamics, 10(3), 473-484.
Zemp, D. C., Schleussner, C. F., Barbosa, H., & Rammig, A. (2017). Deforestation effects on Amazon forest resilience. Geophysical Research Letters, 44(12), 6182-6190.