An ecosystem refers to components such as living organisms and their nonliving elements, which interact in a system (Richardson, 2009, p.5). Ecosystems sustain life through the provision of crucial ecological services such as the conservation of genetic resources, protection of coastlines, and absorption of pollution (Pastor, 2008, p.19)s. Examples of ecosystems of the earth include mountains, forests, deserts, freshwater wetlands, regional seas, oceans, and mangroves and estuaries. Each of these ecosystems occupies a significant space of the earth’s surface; for example, mountain ecosystems occupy approximately 20 percent of the earth’s surface. The current health of ecosystems, however, differs significantly from that of the period before the 18th century (Harrison and Pearce, 2000, p.56). This change is attributed to increased human activity caused by an increase in the population. The extent of forests, which covered a wide part of the earth, for example, is a valid measure of ecosystems' survival; overall, approximately half of the area once covered by forests has been lost to humankind (Raven, 2013).
Human activity has affected ecosystems (Glass, 2005, p.23); since the advent of industrialization, the state of ecosystems has declined substantially. The loss of about 25 percent of the topsoil favorable for agricultural activities, the decline in the area of old growth forests, the loss of species due to activities such as poaching, and the loss of fish species resulting from over-exploitation of water bodies are some examples of the detrimental impacts of the increase in human population and activity. Specifically, increased human activity has resulted in the transformation of a significant space of the earth surface into land for farming, the consumption of 55 percent of renewable freshwater supplies, and the loss of 20 percent of the agricultural land. Additionally, increased human activity has contributed to the alteration of systems such as the atmosphere and the depletion of natural resources such as fuels and marine fisheries. The burning of fossil fuels, for example, has had negative impacts on the earth’s ecosystems through pollution. Most recently, fossil fuel burning has affected climate changes through the saturation of ecosystems with compounds such as nitrogen oxides and ammonia.
References
Glass, S. 2005. Population and Ecosystems. Logan, Iowa : Perfection Learning
Harrison, P. and Pearce, F., 2000. AAAS Atlas of Population and Environment. Berkeley: University of California Press.
Pastor, J. 2008. Mathematical ecology of populations and ecosystems. Oxford: Wiley-Blackwell Pub.
Raven, H., P. 2013. Population and Ecosystems. AAAS. Retrieved from http://atlas.aaas.org/index.php?part=2&sec=eco
Richardson, G. 2009. Ecosystems. New York, NY: Weigl Publishers.
