Urban Ecosystems and observing landscapes

The lecture last week, lead by Dr.Edwards, was on the topic of what a natural ecosystem is and how an urban ecosystem is similar and/or different. Here are some of the interesting things I learned from it:

- The functions of urban ecosystems are to:

  a) improve quality of life

  b) improve environmental conditions (mediates climate, increases carbon storage)

  c) contribute to native plant and animal diversity & population strength

  d) reduce negative human impact on watersheds 

- Factors that control temperature of an ecosystem as well as a specific location are:

  a) slope position and steepness

  b) how shaded the site is

  c) aspect (the compass direction in which the site faces)

- There have been studies that have observed and recorded clear adaptations by plant and animal species to living in urban environments, such as various bird types chirping at higher pitches to compensate for the great amount of noise found in a city

Our class activity for the day was to walk around three urban greenspaces on our near the Georgia State University and observe characteristics such as soils, microclimate, moisture retention, geology, exposure to trampling, plant and animal life, community, and contribution to the functions of urban ecosystems. We found that all three of the greenspaces exhibited clear signs of definitive planning with a focus on aesthetic appeal and not a lot on recreating the natural environment. Here are the places we explored:

outside of the Student Center (Gilmer Street & Courtland Ave)

campus courtyard a.k.a. "The Quad"

Hurt Park

After class ended, I had the wonderful opportunity to go away for the weekend. I went to Florida with my partner and spent the weekend at a small resort on the beach near Tampa and St.Petersburg. Even though I was not intending to observe this environment as an urban ecosystem, the photos I took definitely portray characteristics of the natural environment intersecting with the built environment:

the natural beach and plant life juxtaposed with touristic development

bird life on the beach

commercial development on the waterfront

a drawbridge connecting Tampa Bay to the Gulf of Mexico

while beautiful, these colors tell of high atmospheric pollution levels

Information about Urban Sites and Urban Ecology
from our text, Cities & Nature: (pg.101-117, 142-148) 

1) This text described how the site of a city influences its economy and culture by naming three types of city sites and discussing ways each of them are affected by the area's physical properties:

  - on the beach: cities on oceans inherently develop distinct "beach cultures," with each specific beach having its own demographics, sociocultural differences, economies, and discrimination. the beach is a very contested place, and civil unrest often breaks out over control of desirable areas (example: beaches of Cronulla in December 2005)

  - in the desert: while they present an image of an oasis in a dry and desolate expanse, desert cities struggle with water shortages and are often forced to pipe water in from outside sources which are very far away. even so, desert cities provide a sense of fantasy and luxury due to its inhospitable conditions, which are difficult to maintain (example: Mecca, Saudi Arabia and Las Vegas, Nevada)

  - on a river delta: the river and its regular flooding creates the identity of the are as a port for trade but also poses a threat to its safety/existence. (example: New Orleans' growth and later its decline as railroad industry expansion passes it by, along with its failed levee system due to the urbanization of low-lying lands and numerous hurricanes/flooding)
2) The following list contains flows of energy that power a city, and how they influence energy use:

  - human muscle power: in ancient eras, human labor built and maintained cities
  - fossil fuels: previously coal and recently oil, machines have replaced human power in powering cities
  - electricity: this flow of energy from power plants powers almost everything in the city, and is constantly demanded upon for more 
  - nuclear: a more recent form of energy production which is very delicate and potentially dangerous
  - wind: another factor that influences energy use, with an example being windmill farms producing energy for cities
  - food: natural food cycles are affected in urban centers by economy, culture, and society. this is created by complex relations between distributors and producers, with consumers stuck in the middle and are unequally benefited.
3) "The ecological footprint measures how much land and water area a human population requires to produce the resources it consumes and to absorb its wastes" (Short 143-144).
4) There are three biophysical cycles modified by cities:
  - carbon cycle: the burning of fossil fuels has raised carbon dioxide levels to historic levels and greatly affected the plant processes of photosynthesis and metabolism.
  - phosphorus cycle: while it is found naturally in rocks and absorbed by plants, it is mined and over-used to fertilize crops and therefore seeps into natural water supplies. this causes abnormal algae blooms in bodies of water, which kill other species.
  - nitrogen cycle: even though nitrogen is found in the air and converted into ammonium by plants and bacteria, urban areas burn fossil fuels which create nitrogen oxides. this, and nitrogen-rich fertilizers, causes soil leaching and dead zones in oceans and rivers.