The Impact of Human Activities on the Environment - Essay Example

College: Contents Contents Introduction 2 Background Information 2 Threats to Tropical Forests 4 Discriminatory Plant Extraction 4 Selective Animal Removal 5 Biological Invasions 5 Fragmentation 5 Climate Change 6 Potential Threat Mitigation Measures 6 Conclusion 7 Threats to the Tropical Rainforest Introduction The threat posed by diverse aspects to tropical forests has often been measured on the basis of the extent of deforestation and the area remaining under plant cover. In recent times, however, scholars have come to realize that a tropical forest may seem intact on a satellite generated image, while it could be biologically ruined or be susceptible to complete degradation (Primack and Corlett 15). For this reason, deforestation is not the only threat to the diversity of tropical rainforest, and other potential threats include: selective removal of flora and fauna, biological invasion, fragmentation, increasing rates of tree turnovers and climate change, among others. The potential impact of these threats on biodiversity of tropical forest is difficult to assess, due to the fact that the threats could be interlinked and each precipitates either direct or indirect effects. Regardless of the uncertainties associated with threat evaluation and impact assessment, the fact that these forests are subject to radical ecological changes, hence degradation is indubitable. For these reasons, it is imperative for conservationists and the global populations, to monitor, comprehend, and prevent the negative impact of these threats at all costs. Background Information Most studies in Earth systems reveal the fact that Tropical rainforests represent one of the World’s oldest and uninterrupted ecosystems. For instance, fossil records indicate that South-east Asia’s humid forests have been in existence for between 70 and 100 million years, without much alteration to their original form. Tropical rainforests make up some of the world’s haven for species, since they could have more than 1000 different species within an area of one square kilometer (km2). This is a very large proportion of both floral and faunal species, in comparison to that found in temperate forests, which harbor a meager 100 species within a similar spatial area. Tropical rainforests cover an estimated 2% area of Earth’s surface, which amounts to approximately 2000 million hectares (Ha). These forests get their name “Tropical” from their location within the tropics, that is, the Tropic of Capricorn about 23 degrees south and the Tropic of Cancer about 23 degrees north of the Equator (Primack and Corlett 15). Given the strategic location of Tropical rainforests within the tropics, they span across most of the world’s continents, including Africa, Asia, Northern Australia, and South America. These forests are also found in many of the tropical islands within these areas (Wright 554-555). The Amazon Rainforest is the largest of the Tropical rainforests in the world. Found in South America, the Amazon forest covers eight nations including Bolivia, Brazil, Colombia, Guyana, Peru, Venezuela, Suriname and Ecuador. This huge forest covers a 2 million square miles area. Studies have shown that Tropical rainforests play a significant role in regulating local, as well as, global climatic conditions, in addition to regulating the crucial carbon cycle. The forests regulate the carbon cycle by absorbing and storing large amounts of carbon, while releasing much needed oxygen to the environment. This happens when the vast number of plants takes up carbon during photosynthesis, thus incorporating it into stored biomass. Even though there is no agreement as to whether preserved rainforests constitute the principal sink or source of carbon, negative influences of excessive deforestation are clearly known. Additionally, the role of deforestation in negating the carbon cycle is indubitable (Fearnside 681). Over the last several years, discussions regarding the links between forests’ depletion and climate change have been on the rise. This is an aspect attributable to two principal reasons. The first reason is that, depletion of rainforests leads to alteration of hydrological cycles, as well as, patterns of weather, and extensive loss of biodiversity. Additionally, there are situations where deforestation occurs through utilization of fires, because the practice is both swift and cheap. This leads to production of a large amount of greenhouse gases (GHGs), further contributing to the prevalent global warming problem. The second principal factor, fuelling the mentioned discussion is that, depletion of forests usually leads to cumulative influences. Some of these effects include micro-climate changes, increased soil erosion and occurrence of droughts. It is imperative to note that depletion of rainforest can worsen the global warming problem, while the latter also poses numerous threats to continued survival of the forests. For instance, changing patterns of rain and higher temperatures could not only affect animals and plants negatively, but these trends may also create conditions necessary for increment of forest fires. Further, the abrupt temperature elevation may deter plants from adapting equally fast, increasing chances of extinction. These worrying trends emphasize the fact that the world’s tropical rainforests need protection, in order to avoid aggravation of threats posed by climate change (Fearnside 683). Threats to Tropical Forests Specific threats to tropical forests are discussed hereunder, with both direct and indirect examples of the threat, either to plants or animals clearly shown. Additionally, the threat examples and summaries take into consideration interactions with other potential threats. Discriminatory Plant Extraction Virtually all plants in a tropical rainforest may be extraction targets for humans. This is due to the fact that most plant products are usually utilized for a wide array of both commercial and subsistence purposes. Forest plants’ exploitation may entail continuous harvesting of specific species without replenishment or execution of sustainability strategies (Wright 556). This leaves behind a standing yet economically and biologically degraded forest. Other than excessive selective logging, discriminatory extraction of plant resources results in radical structural variations of a forest. To deal effectively with this threat, it is not enough just to reaffirm the pristine nature of forest cover from satellite images. This is because, such images may indicate that a forest is still intact, yet it has been mined of all economically and biologically distinctive plants. Instead, local experts must be involved in the assessment process, in order to ensure that the actual status of a forest at the ground level is known, and that conservation strategies formulated are in synch with problems at hand (Ravenel and Granoff 43). Excellent examples of selective plant extraction from tropical forests, include exploitation of distinctive tree species like Swietenia macrophylla (mahogany tree), as well as, Cedrela odorata (the South American cedar). These trees have been completely depleted from some tropical forests, even in regions reported to have 100% plant cover. Another example is the complete depletion of certain medicinal plants and fruit trees within about 100 km of Iquitos, a small Peruvian city. This is a negative trend attributable to the fact that, locals prefer to cut down trees in order to get latex or fruits, instead of climbing or tapping the plant products from the ground (Ravenel and Granoff 45). The threat of selective plant exploitation is accentuated by the possibility of plant inbreeding. This happens in situations where the surviving plant species are scattered far and wide, thus cannot cross-breed. This is a risky trend since it lowers genetic diversity hence capability of plants to survive. Other than predisposition of plants to extinction, discriminatory harvesting of plants completely alters a forest’s structure and increases its susceptibility to fires. Selective Animal Removal Increased demand for fashionable items made from animal parts such as ivory jewelry, fur coats, and varying leather shoes or apparel, among other things, is posing great danger to animals in tropical forests. Research has shown that a very limited tropical forest area provides safe haven for diverse animals. Devastation of fauna may take place either through subsistence hunting, where humans need certain animals for food, or for commercial purposes. Specific animals under the threat of extinction include Caymans, alligator like reptiles mainly found in tropical rivers such as the Amazon River. Others are elephants, hunted for their ivory tasks and white rhinoceros, valued for their horn and hide (Pearce, Putz and Vanclay 230-232). Biological Invasions Another serious threat to tropical rainforests is introduction of new or exotic plant, as well as, animal species. Even though these species may be important in fighting hunger and guaranteeing food security in a world showing rapid population growth, they pose a great risk to endemic species. This is because; exotic plants or animals usually have higher competitive ability on comparison to indigenous species. As a result, the species may turn out to be invasive thus completely depleting the native ones (Pearce et al., 233). Fragmentation Spatial fragmentation refers to the division of land into segments that have distinctive features in comparison to those of the original area. In this case, portions of tropical forests are being cleared to pave way for human settlement, plantations and other activities. This implies that most tropical forests are discontinuous, an aspect that brings about human-animal conflicts, introduction of invasive species, and detrimental isolation of native species. Spatial attributes of fragmentation are usually visible and quantifiable, while using satellite imagery (Primack and Corlett 42). Nevertheless, ensuing decay and degradation of tropical rainforest ecosystems, in isolated parts is primarily indiscernible from above. With other forest features constant, large fragments have the capacity to support many species in comparison to small fragments. Typically, tropical rainforests can harbor many, unique biological communities. Among these communities there are species, which thrive best in restricted surroundings, making them highly vulnerable to extinction in the advent of land subdivision. This is because the biological communities, once isolated, get exposed to the vagaries of weather, and diminution of genetic multiplicity. Further, smaller forest fragments become particularly susceptible to edge effects, such as easy penetration and additional species extraction (Primack and Corlett 44). Climate Change Recent investigative studies indicate that regions around the tropics could be highly vulnerable to climatic changes that the globe is currently experiencing. For instance, in the previous ice-age, tropical temperatures could have been a lot lower than they are currently (Primack and Corlett 63). This implies that as temperatures continue to increase, there is a high possibility that tropical rainforests may experience more powerful and more frequent hurricanes. Additionally, such regions are likely to experience greater season extremities between the dry and wet times of the year. Since seasonality is one of the key determinants of: the type of vegetation, biological activity and species diversity within the tropics, weather extremes will be highly detrimental (Fearnside 684). Potential Threat Mitigation Measures A potentially effective way of tackling tropical rainforest depletion, and other damaging threats, would be to ensure active engagement of local communities in conservation efforts. This can be attained through provision of incentives, such as retention of tourism fees, and being assigned land in places far from the forest. This will ensure that such individuals have a stable source of income, and at the same time, they are motivated to utilize forest resources in a sustainable manner for the benefit of future generations. Additionally, rainforests conservation measures must be coupled with attempts to cut GHGs’ emissions in both developing and industrialized nations (Pearce et al., 245). Other key threat mitigation measures include: Encouraging people to conserve tropical rainforests, by educating them about the importance of the forests in fostering biodiversity and balancing climatic conditions. Giving people income alternatives, in order to discourage their involvement in plant or animal extraction. Formulating and effectively executing land tenure privileges for locals, not only to motivate their conservation efforts, but also to prevent them from settling in these forests. Imposing fines and other legal penalties for individuals found extracting endangered plant or animal species. Conclusion Working on this paper gave me deeper insight into the potentially immense impact of human activities on the environment. I came to realize that threats to tropical rainforests are not only detrimental to local communities, but to the world as a whole. For this reason, protection of tropical rainforests is a global concern and not the sole responsibility of concerned countries or communities. Finally, efforts to deal with the discussed threats must prioritize the interests of concerned people. This would be preferable to treating affected people and the prevalent problem as separate entities, a negative attribute evident in contemporary conservation measures. For this reason, the concerned individuals must take a prominent role in the discussion attempting to formulate conservation strategies. Most importantly, I learned that tropical rainforests conservation efforts must be synchronized with the attempts to deal with challenges posed by climate change. Works Cited Fearnside, Philip. “Deforestation in Brazilian Amazonia: history, rates, and consequences.” Conservation Biology 19 (2005): 680–688. Pearce, David, Putz, Francis, and Vanclay, Jerome. “Sustainable forestry in the tropics: panacea or folly.” Forest Ecology and Management 172(2003): 229–247. Primack, Richard and Corlett, Richard. Tropical Rain Forests: An Ecological and Biogeographical Comparison. Oxford: Blackwell Science. 2005. Print. Ravenel, Ramsay and Granoff, Ilmime. Illegal logging in the tropics: strategies for cutting crime. New York: Haworth Press, Food Products Press. 2004. Print. Wright, Joseph. “Tropical forests in a changing environment.” Trends in Ecology and Evolution 20 (2005): 553–560. Read More