Discussion of “Urban morphology drives the homogenization of tree cover in Baltimore, MD, and Raleigh, NC”

A major focus of this study is to examine the drivers of urbanization and its effects of city look and feel. Studies have shown that cities are beginning to more like each other and contrasting more with the biome in which they are located. Drivers can be considered either top-down or bottom-up.
Top down:
  • Government land-use policies
  • Permeable surfaces
  • Lot size
  • Type of building
Bottom up:
  • Cultural values
    • Luxury effect
    • Ethnicity- different in landscape preferences between ethnic groups
Continuous and categorical variables were used as predictors of tree coverage and ranked below.
  1. 1. Urban morphology (parcel size and characteristics, development patterns)
  2. 2. PRIZM (socio-economic systems, data set generated from consumer data )
  3. 3. Bivariate analysis
Historical legacies a strong predictor of tree coverage in Baltimore. Baltimore is an older city than Raleigh. Historical legacies may be a better predictor for tree coverage in Raleigh in the future.
Parcel size important in future of both cities. Small parcel size in Baltimore due to historical limitations of the city. Small parcel size in Raleigh due to future limitations in travel distance. Raleigh currently has a high tree cover (50%). If Raleigh follows trend of other cities then it is expected to lose tree cover over time.

Discussion of “Urban ecology in a developing world: why advanced socioecological theory needs Africa”

Urbanization increasing in Africa, India, China. Urbanization in Africa and the “Global South” are different than the “Global North”. Therefore the cities and urban areas of the “Global South” may not develop in the same way that urban areas of the “Global North” have developed.
Migration to African cities is decreasing, birth rates are still increasing. Families can be considered to be both urban and rural if individuals live in the city and send resources back to rural family.
Rural areas becoming more urban, that’s where the urbanization is occurring in South Africa. Urbanization is largely a result of re-classification of rural to urban. Many ‘rural’ areas look more like suburban areas of “Global North”. But there are also informal settlements that have no analogous structure in “Global North”.
Kruger National Park is already being pressured by anthropogenic forces. Many people were moved towards land surrounding the park during Apartheid. Current settlements are “rural/urban” areas of low resource availability. Conservation efforts in the area are focused on ecosystem management of large areas, much of which includes these settled areas. These small villages are not concerned with large-scale conservation but on resources necessary for their settlement.

The following livelihood framework was proposed as an alternate to the Press-Pulse Dynamic (PPD) framework presented previously in class. This framework places a greater emphasis on humans and presents various scales (individual-ecosystem, individual-society).

Comments after class from Kelly Suttles:While I drove home after class I continued to think about the question Dr. McHale posed to us in answer to my question about further research in the urban homogenization question. (Her question was along the lines of how to bring all this great urban ecology research to the community.) This made an impression, because it was not the response I expected and I like that she talked about geting out of the "ivory tower." I too am very interested in applied research.

I think there should be many different approaches for urban ecology outreach. The idea that came to me could be to offer basic gardening workshops to the people surveyed who prefer the native landscape or want more trees, etc. Dr. McHale's students could partner with NC Cooperative Extension, the NC Botanical Garden at UNC, and/or the NC Wildlife Federation (just a few examples) to offer the workshops. (UNC has a great native plant program, but maybe NC State has something similar). In lower income neighborhoods maybe UNC would donate some small native plants for participants with a "pay-it-forward" request.

The workshops could be simple, really just the basics.
  • Introduce the concept of native plants and what the native ecosystem of this area would look like.
  • Introduce some easy to propagate native plants - a few for sunny locations and a few for shady locations. Don't overwhelm beginners with lots of choices.
  • Express that these plants are low maintenance, increase biodiversity, and protect surface water run-off.
I agree that socio-economic status/environmental justice always needs to be considered. So the workshops for renters would be different assuming they can't just go start a garden wherever they want. In this case you would need to partner with city parks to make sure the participants could plant native plants in a nearby park. Then the park managers could purchase the plants and the residents could do the planting and care.

I think this could be a very interesting model for urban ecology. It empowers urban residents in a new way to take positive environmental action. I don't think most people realize how much their little parcel of land in the city can impact the larger ecosystem. So this is just giving people the tools to make better decisions.

Similar ideas happening in Durham are rain garden workshops to help protect the extremely urban Ellerbe Creek watershed and there is also a street trees program to identify and plant trees along street right of ways.
Please add your thoughts, comments, questions below.