Why do we care about the loss of biodiversity in cities?
Before reading any further, it is important to note that there are countless ways in which biodiversity is crucial to life on Earth. However, this site will focus primarily on the immediate impacts of biodiversity in cities, especially those in the Seattle area.
When a city is built, little if any of the pre-existing habitat is left unscathed. When the city is complete, the landscape is often completely unrecognizable. The habitats that existed for so long are largely gone, and with massive changes in habitat comes a drastic change in which species are present. The species that remain are the ones that survive in our urban environment, and even then they are usually not as abundant as they once were. In an urban environment, there is little biodiversity compared to what the natural habitats held.
As terrible as the loss of beautiful habitats and creatures is, why should city-dwellers care that biodiversity has dropped so dramatically?
Increases Environmental Stability
With decreases in biodiversity, the ecosystem becomes much more fragile. This means that when catastrophic (stochastic) events occur, the ecosystem cannot recover as well and species may run the risk of becoming threatened or even extinct much more easily than if the habitat held rich biodiversity before the stochastic event [1].
Decreases Risk of Flooding
In fact, a loss of biodiversity may even help to cause these stochastic events. A common example is that of lack of plant habitat leading to dramatic increase in flooding. In fact, the global risk of floods in large port cities like Seattle could increase to nine times its present risk in the next 35 years [2]. Though this increase is not entirely due to the lack of biodiversity in urbanized areas, the lack of diverse and prevalent root structures drastically decreases the soil's ability to hold water and flooding is the result.
Mitigates Effects of Climate Change
Climate change is one of the greatest stochastic events to come in the near future. Species are already beginning to move into regions resembling their original climates, causing massive and extremely rapid changes to many ecosystems. Ocean dwellers are less fortunate, and many of them simply cannot survive the warmer water temperatures expected to become prevalent in the next few decades [3]. However, the number and type of species present, their relative abundance, the interactions between them, and their temporal and spacial variation can affect energy flows, essentially helping to determine where energy goes after it hits the plants' leaves. This may not seem like much, but it can have a direct impact on climate [4].
When a city is built, little if any of the pre-existing habitat is left unscathed. When the city is complete, the landscape is often completely unrecognizable. The habitats that existed for so long are largely gone, and with massive changes in habitat comes a drastic change in which species are present. The species that remain are the ones that survive in our urban environment, and even then they are usually not as abundant as they once were. In an urban environment, there is little biodiversity compared to what the natural habitats held.
As terrible as the loss of beautiful habitats and creatures is, why should city-dwellers care that biodiversity has dropped so dramatically?
Increases Environmental Stability
With decreases in biodiversity, the ecosystem becomes much more fragile. This means that when catastrophic (stochastic) events occur, the ecosystem cannot recover as well and species may run the risk of becoming threatened or even extinct much more easily than if the habitat held rich biodiversity before the stochastic event [1].
Decreases Risk of Flooding
In fact, a loss of biodiversity may even help to cause these stochastic events. A common example is that of lack of plant habitat leading to dramatic increase in flooding. In fact, the global risk of floods in large port cities like Seattle could increase to nine times its present risk in the next 35 years [2]. Though this increase is not entirely due to the lack of biodiversity in urbanized areas, the lack of diverse and prevalent root structures drastically decreases the soil's ability to hold water and flooding is the result.
Mitigates Effects of Climate Change
Climate change is one of the greatest stochastic events to come in the near future. Species are already beginning to move into regions resembling their original climates, causing massive and extremely rapid changes to many ecosystems. Ocean dwellers are less fortunate, and many of them simply cannot survive the warmer water temperatures expected to become prevalent in the next few decades [3]. However, the number and type of species present, their relative abundance, the interactions between them, and their temporal and spacial variation can affect energy flows, essentially helping to determine where energy goes after it hits the plants' leaves. This may not seem like much, but it can have a direct impact on climate [4].
Human Benefits
If you believe that these significant changes to our ecosystem don't affect you, think again. Human health greatly benefits from a healthy surrounding environment. For one, with healthy ecosystems we are more inspired to enjoy the beautiful outdoors and reap the benefits of rare Seattle sun, exercise, and fresh air. On a more serious note, medical conditions like asthma are much more aggravated by pollutants in the air, and the greater the biodiversity, the cleaner our air is and the healthier we may keep our lungs. The lungs shown on the left are from a healthy, city resident [5]. Notice the abnormal, black chemical deposits.
Improves Air Quality
Not only does cleaner air affect humans, but it affects a whole host of other living organisms as well. When talking about biodiversity within cities, it is important to note how interconnected various species are, even when there are much less of them than there would be in natural habitat. One striking example of the importance of biodiversity is when rich animal biodiversity leads to more plants overall, let alone increase plant biodiversity. In some cases, inconspicuous insects are the ones to thank. Insects represent an enormous part of our earth's biodiversity, and many studies have linked increased insect populations to increased tree populations [6]. Insects and trees are extremely important in general, but in our urban environments especially. This is because trees are notorious for pulling air pollutants out of the air, and of course, producing the oxygen that we breathe [7]. Not only does this improve our air quality and lead to better health, but trees trap greenhouse gasses affecting climate change and can further mitigate the atmospheric damage wrought by humans.
Improves Water Quality
In addition to improving air quality, biodiversity directly impacts the groundwater we use for drinking. In much the same way trees trap air pollutants, various plants trap human wastes from infiltrating the groundwater we use every day [8]. This is a major concern for cities, as harmful chemical waste from roads, fertilizers, and pesticides can easily leech into the ground with little plant growth to stop them and allow them to get absorbed before entering the groundwater.
Primary Sources
1. Pimm, Stuart L. "Causes, Consequences and Ethics of Biodiversity." The Quarterly Review of Biology 73.1 (1998): 208-11. Print.
4. Iii, F. , S. Chapin, E. S. Zavaleta, V. T. Eviner, R. L. Naylor, P. M. Vitousek, H. L. Reynolds, D. U. Hooper, S. Lavorel, O. E. Sala, S. E. Hobbie, M. C. Mack, and S. Díaz. "Consequences of Changing Biodiversity." Nature 405.6783 (2000): 234-42. Print.
6. Murdoch, William W., F. C. Evans, and C. H. Peterson. "Diversity and Pattern in Plants and Insects." Ecology 53.5 (1972): 819-29. Print.
8. Brown, J., A. Wyers, A. Aldous, and L. Bach. "Groundwater and Biodiversity Conservation." Science to Sustain the Pacific Northwest. Washington Conservation Science, n.d. Web. 25 Feb. 2014. <http://www.waconservation.org/>.
Secondary Sources
2. "Future Flood Losses in Major Coastal Cities." OECD. OECD, 19 Aug. 2013. Web. 25 Feb. 2014. <http://www.oecd.org>.
3. "Sea Temperature Rise." The Ocean. National Geographic, n.d. Web. 24 Feb. 2014. <http://ocean.nationalgeographic.com/ocean>.
5. "Respiratory System." NMHM. National Museum of Health and Medicine, n.d. Web. 03 Mar. 2014. <http://www.medicalmuseum.mil/>.
7. "Clean Air & Water." American Forests. American Forests, n.d. Web. 25 Feb. 2014. <http://www.americanforests.org>.
If you believe that these significant changes to our ecosystem don't affect you, think again. Human health greatly benefits from a healthy surrounding environment. For one, with healthy ecosystems we are more inspired to enjoy the beautiful outdoors and reap the benefits of rare Seattle sun, exercise, and fresh air. On a more serious note, medical conditions like asthma are much more aggravated by pollutants in the air, and the greater the biodiversity, the cleaner our air is and the healthier we may keep our lungs. The lungs shown on the left are from a healthy, city resident [5]. Notice the abnormal, black chemical deposits.
Improves Air Quality
Not only does cleaner air affect humans, but it affects a whole host of other living organisms as well. When talking about biodiversity within cities, it is important to note how interconnected various species are, even when there are much less of them than there would be in natural habitat. One striking example of the importance of biodiversity is when rich animal biodiversity leads to more plants overall, let alone increase plant biodiversity. In some cases, inconspicuous insects are the ones to thank. Insects represent an enormous part of our earth's biodiversity, and many studies have linked increased insect populations to increased tree populations [6]. Insects and trees are extremely important in general, but in our urban environments especially. This is because trees are notorious for pulling air pollutants out of the air, and of course, producing the oxygen that we breathe [7]. Not only does this improve our air quality and lead to better health, but trees trap greenhouse gasses affecting climate change and can further mitigate the atmospheric damage wrought by humans.
Improves Water Quality
In addition to improving air quality, biodiversity directly impacts the groundwater we use for drinking. In much the same way trees trap air pollutants, various plants trap human wastes from infiltrating the groundwater we use every day [8]. This is a major concern for cities, as harmful chemical waste from roads, fertilizers, and pesticides can easily leech into the ground with little plant growth to stop them and allow them to get absorbed before entering the groundwater.
Primary Sources
1. Pimm, Stuart L. "Causes, Consequences and Ethics of Biodiversity." The Quarterly Review of Biology 73.1 (1998): 208-11. Print.
4. Iii, F. , S. Chapin, E. S. Zavaleta, V. T. Eviner, R. L. Naylor, P. M. Vitousek, H. L. Reynolds, D. U. Hooper, S. Lavorel, O. E. Sala, S. E. Hobbie, M. C. Mack, and S. Díaz. "Consequences of Changing Biodiversity." Nature 405.6783 (2000): 234-42. Print.
6. Murdoch, William W., F. C. Evans, and C. H. Peterson. "Diversity and Pattern in Plants and Insects." Ecology 53.5 (1972): 819-29. Print.
8. Brown, J., A. Wyers, A. Aldous, and L. Bach. "Groundwater and Biodiversity Conservation." Science to Sustain the Pacific Northwest. Washington Conservation Science, n.d. Web. 25 Feb. 2014. <http://www.waconservation.org/>.
Secondary Sources
2. "Future Flood Losses in Major Coastal Cities." OECD. OECD, 19 Aug. 2013. Web. 25 Feb. 2014. <http://www.oecd.org>.
3. "Sea Temperature Rise." The Ocean. National Geographic, n.d. Web. 24 Feb. 2014. <http://ocean.nationalgeographic.com/ocean>.
5. "Respiratory System." NMHM. National Museum of Health and Medicine, n.d. Web. 03 Mar. 2014. <http://www.medicalmuseum.mil/>.
7. "Clean Air & Water." American Forests. American Forests, n.d. Web. 25 Feb. 2014. <http://www.americanforests.org>.