Habitat Loss and Degradation
Complete Loss of Habitat
Of all the previously mentioned factors, habitat loss is the most responsible for species extinction and endangerment [10]. Cities are the most extreme cause of habitat transformation. Once a city has been built, the habitat can no longer be considered degraded, but is now "lost" [10]. When a habitat is degraded, that means the habitat was negatively changed or altered in some way. To say that a habitat is lost means that there is hardly, if any, original habitat left. Seattle is one example of a large urban area responsible for vast amounts of habitat loss, and that is only considering the area taken by the city inhabitants.
Far Ranging Effects
In fact, the effects of a city are much farther reaching, for habitats around the globe must be drastically modified to grow the food inhabitants need. For example, Vancouver BC had an ecological footprint 174 times its area in 2002, and it has probably grown since then as the city has grown [11]. Unfortunately, loss of habitat is one of the most devastating blows to biodiversity, for it singlehandedly destroys the living space of countless different species and often leaves them without basic necessities such as food or natural breeding grounds.
Loss of Habitat Connectivity
Even if cities leave patches of natural habitat, species still suffer from habitat fragmentation. Species need room to disperse their seeds/find mates. If their normal habitat is suddenly bisected by a massive city, it becomes virtually impossible for many species to reproduce, forage, or roam as they did before. This has many effects, including loss of genetic diversity leading to inbreeding and decreased success in reproduction. Other species, notably large predators, no longer have a big enough range to gather enough food. Many of these species have large, hardly overlapping ranges to begin with, and if urbanization gets in the way of a male's range and prevents him from finding females, the local population of the species may go extinct relatively quickly.
Secondary Sources
10. Groom, M. J., G. K. Meffe, and C. R. Carroll. Principles of Conservation Biology. 3rd ed. Sunderland: Sinauer, 2006. 187-89. Print.
11. "UNEP Annual Report for 2002." UNEP-Publications. UNEP, 2003. Web. 25 Feb. 2014. <http://www.unep.org>.
12. "An Assessment of Assemblage Nestedness in Habitat Fragments." TIEE. Teaching Issues And Experiments In Ecology, 23 Feb. 2009. Web. 02 Mar. 2014. <http://tiee.ecoed.net/vol/v6/experiment/assessment_assemblage/description.html>.
Of all the previously mentioned factors, habitat loss is the most responsible for species extinction and endangerment [10]. Cities are the most extreme cause of habitat transformation. Once a city has been built, the habitat can no longer be considered degraded, but is now "lost" [10]. When a habitat is degraded, that means the habitat was negatively changed or altered in some way. To say that a habitat is lost means that there is hardly, if any, original habitat left. Seattle is one example of a large urban area responsible for vast amounts of habitat loss, and that is only considering the area taken by the city inhabitants.
Far Ranging Effects
In fact, the effects of a city are much farther reaching, for habitats around the globe must be drastically modified to grow the food inhabitants need. For example, Vancouver BC had an ecological footprint 174 times its area in 2002, and it has probably grown since then as the city has grown [11]. Unfortunately, loss of habitat is one of the most devastating blows to biodiversity, for it singlehandedly destroys the living space of countless different species and often leaves them without basic necessities such as food or natural breeding grounds.
Loss of Habitat Connectivity
Even if cities leave patches of natural habitat, species still suffer from habitat fragmentation. Species need room to disperse their seeds/find mates. If their normal habitat is suddenly bisected by a massive city, it becomes virtually impossible for many species to reproduce, forage, or roam as they did before. This has many effects, including loss of genetic diversity leading to inbreeding and decreased success in reproduction. Other species, notably large predators, no longer have a big enough range to gather enough food. Many of these species have large, hardly overlapping ranges to begin with, and if urbanization gets in the way of a male's range and prevents him from finding females, the local population of the species may go extinct relatively quickly.
Secondary Sources
10. Groom, M. J., G. K. Meffe, and C. R. Carroll. Principles of Conservation Biology. 3rd ed. Sunderland: Sinauer, 2006. 187-89. Print.
11. "UNEP Annual Report for 2002." UNEP-Publications. UNEP, 2003. Web. 25 Feb. 2014. <http://www.unep.org>.
12. "An Assessment of Assemblage Nestedness in Habitat Fragments." TIEE. Teaching Issues And Experiments In Ecology, 23 Feb. 2009. Web. 02 Mar. 2014. <http://tiee.ecoed.net/vol/v6/experiment/assessment_assemblage/description.html>.