Urban Ecology as a science is becoming increasingly more important in the field of biology as more and more people are moving to urban/city centers. Urban ecology, before we begin is defined as “the scientific study of the relation of living organisms with each other and their surroundings in the context of an urban environment.” An urban environment can vary, but common characteristics include:
- A location with a high density of human inhabitants
- A fragmented landscape – the landscape is not uniform, could include patchy grassy areas surrounded by buildings and other human built material.
- Location with a great amount of food waste
- An environment with impervious surfaces where water cannot pass through such as concrete or asphalt.
One characteristic of a urban environment is that it tends to attract/trap heat. This effect is called the Urban Heat Island Effect. In cities, the downtown areas tend to me a few degrees (Celsius) higher than the surrounding natural landscape. Things like asphalt attract and trap the sun’s rays, and cars give off heat from their engines and fumes, which also increase the surrounding temperature. The problems that are revealed through urban ecology include the Urban Heat Island Effect, as well as others, and we see that they are all human induced. Urbanization and the ecological cascades are all caused by humans. According to the article “The ecological future of cities”, no much is know about the ecology of cities itself, but there is awareness of the problems associated with cities such as pollution. According to the article, by 2050 an additional 2.5 Billion people are expected to live in urban environments. In 2014 there was already 4 billion people living in urban centers!
Photo from Pxhere
For this week’s lab we studied ants and the effects Urbanization and the importance of understanding how urban environments impact the availability of food and its quality compared to that of a natural environment. This week, we merely took samples from 4 different locations across campus and calculated impervious surfaces (using the pace to plant method) surrounding each site as an indication of urbanization. 6 food groups were laid out at each site for 1 hour and then recollected along with the ants they contained.
Our data has not yet been combined with the rest of the class, so it is difficult to see a correlation with so few samples, however inferences can be made and it seemed like the ants were more abundant in place where it was about 50% impervious surface. The site with the most ants found overall was one that was right on the line between a green space and pavement.
Looking at the New York Times article by Nicholas Bakalar, a similar experiment took place in New York that looked at ants and their food preferences.
- For both our school experiment and the scientific study from the article “Bugs in Manhattan Compete with Rats for Rood Refuge” the “junk food” (or sugar) was the food source that seemed to be the most popular with the ants. The study only used food higher in sugars however, and our school experiment also added in carbs, fats, and proteins. However, the cookie that was used in our experiment seemed to be (without counting each individual ant collected) the food source that attracted the most amount of ants per site. Differently from the New York Times study is that, for our study, we used both green places and pavement as sites to set our bait. In the New York study they only used green spaces to collect their data.
- Looking at city centers, it does make sense that urban areas can be good for biodiversity, at least for some species. Food sources are usually greater in city centers because of human waste. Humans have trash and restaurants and other places where food is abundant. There is more food available and more varieties as well for certain species. Green spaces do exist in city centers and it is there where there is an environment similar to that of one that exists in nature, only more food sources are available due to humans. The increased food sources can allow for a greater distribution of species to flourish.
- Other than ants there are other species that would flourish in cities. Rats are known to have massive populations in cities because their diet is incredibly diverse. Certain decomposers and flies would be able to live off rotting food sources such as produce. Scavenging squirrels could inhabit green spaces but also venture onto more impervious surfaces to find food sources. However, there are many species that would be vulnerable in an urban environment. Butterflies, snakes, farm animals and many others would not flourish due to the lack of vegetation. Larger mammals would not be able to survive as well due to lack of vegetation and additional food sources. Many larger herbivores would not be able to find enough food to sustain them and could not live off human trash due to their diets being more restrictive.
- Humans have a lot cut out for them in order to have city systems functioning more like an ecosystem. The problem with cities is that they are man made. It is a man made environment however, nature still runs its course. In order for cities to improve their function as ecosystems cities need to act more like a natural environment one would see elsewhere. This includes adding more green spaces and improving the air quality. Also, finding solutions to lessen the Heat Island Effect would benefit the city spaces to make the environment more like those surrounding the city.
Photo from Pxhere
The Frontiers in Ecology and Evolutions Urban Ecology page is an important website in researching Urban Ecology. Not much is knows about the ecology of urban environments, so this page has some of the highlights of current studies.
Looking at the 2017 study titled “On-Board Video Recording Unravels Bird Behavior and Mortality Produced by High-Speed Trains” one can get a hint of how urbanization has an impact one one organism.
1a) The study mentions the useable of new high speed trains that will lower energy consumption, which is a good idea when looking for solutions to improve the function of cities as an ecosystem. However, a consequence of this seemingly good solution is that birds are being killed by trains because of the fast speed of the train cars, and so birds cannot get off the tracks in time. The study is interesting because it repeatedly mentions that there is not much information about bird mortality due to trains, and so this therefore leaves the subject open to more researchers. The study leaves questions behind that other scientists could do their additional research off of.
2a) A takeaway from this scientific article that the public should be aware of is that even though a solutions may seem to be environmentally friendly, such as saving fossil fuels by using high speed trails, there is also consequences that need to be addresses, such as that of bird mortality on rail tracks.
3a) Questions I would ask the authors of the study would have to do with what good is the information? What is the next step in high speed trains? Should they be used or does there need to be more data before more engineering ideas are used?
Looking at the 2018 study titled “Nitrogen Biochemistry of an Urban Rooftop Farm” the subject the article studies (N and Rooftop Farms) is an example of another way that urban centers can be aided to improve the function of a city as an ecosystem.
1b) I found the article interesting because it is revealed that rooftop farms (especially in cities) are good for more than just providing fresh produce. Rooftop farms also aid to “reduce N loss to storm drains, which affects aquatic ecosystems and water quality” (Harada, Y. et al).
2b) Based on my readings I think one of the key things the public should take away from reading the article is that green roofs can improve city air quality. Also, the soil used on the rooftops can leech N from fertilizer if using a specific type of soil. In addition, by adding stormwater management systems, soil is a key factor in retaining the access water from impermeable sources as well as holding and recycling toxins.
3b) If I could ask the authors questions I would be curious about other storm management strategies in cities and which one has the best environmental impact. I would also want to know more about Nitrogen in city centers and what other things the element has a role in that I am unaware of.
References
Dade et al. 2016.
Garcia de la Morena, E. L., Malo, J. E., (et al). (2017). On-Board Video Recording Unravels Bird Behavior and Mortality Produced by High-Speed Trains. Frontiers in Ecology and Evolution.
Harada, Y., Whitlow, T. H. (et al). (2018). Nitrogen Biogeochemistry of an Urban Rooftop Farm. Frontiers in Ecology and Evolution. doi: 10.3389/fevo.2018.00153.
Jacoby, W. G. (1994). Public attitudes toward government spending. American Journal of Political Science, 38(2), 336-361.
McDonnell, M. J., MacGregor-Fors, I. (2016) The Ecological Future of Cities. Science, 352(6288), 936-938.
UTC Ecology Lab Blog 