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Urbanization_&_UrbanEcology

Are cities the same from an ecological perspective?

Urban Ecology

Land Use Classification

Here is what you always include when doing a site description:

  1. Land use classification
    • 'Residential'
    • 'Commercial'
    • 'Green area'
    • 'Industrial'
    • 'Conservation'
  2. The dominant human activity on the site
  3. Variable 1: Urbanization intensity (usually assessed using built cover)
    • The proportion of Impervious Surfaces
      • 0 - 33% built cover = "Sparsely developed"
      • 34 - 66% built cover = "Moderately developed"
      • 67% - 100% built cover = "Highly developed"
  4. Variable 2: human activities - noise, pedestrian/vehicle activities, etc.

Rural vs Exurban

Both rural and exurban are sparsely populated areas compared to "urban" zones. 

Rural - surrounded by agricultural land

Exurban - surrounded by natural habitat ("embedded in a natural habitat matrix", according to the lecture slides)

Urban Ecology

Urban ecology is the ecology in, of, and for cities.

 

5 Urban Ecology Principles

  1. Cities are ecosystems - urban ecosystems will still have biotic and abiotic interactions
  2. Cities are spatially heterogeneous - urban ecosystems will contain diverse, multidimensional, and remnant/emerging biota distributed heterogeneously across the landscape
  3. Cities are dynamic - urban ecosystems will host various natural processes that are heavily reactive to cultural, economic, and regional pressures. Closely related to Principle 4.
  4. Cities link human and natural processes - Species richness can be affected by regional socioeconomics. Urban effects can spill/integrate into surrounding rural/natural areas. When wealth correlates with species richness, it is called the Luxury Effect.
  5. Cities will still host/operate ecosystem processes - Nature does not stop after a site is developed.

Remember, Biodiversity is...

The variability among living  organisms, from genes to biomes. This  encompasses diversity within, and among,  species and ecosystems. (Lecture 5 Slides)

3 Diversity elements

  • Genetic Diversity - Total genetic information of an individual to a group of species. Basically the adaptive capacity of a species/groups of species
  • Species Diversity - Total number and distribution of species that occupy a community
    • Species richness - number of species
    • Species evenness - distribution of species
    • Species diversity can be viewed by: rarity - low abundance or endemic to a limited region, or impacts - how one species can have a larger footprint on other species than expected.
  • Ecosystem Diversity - Total complexity of an ecosystem
    • Vertical diversity - # of trophic levels
    • Horizontal diversity - # of species in one trophic level
    • Ecosystem function - all biological and biogeochemical processes that play in a community