Geog 242: Ecology of UrbanizationSpring 2004

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Geog 242 Ecology of Urbanization
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Why ecology of urbanization?

• Global population is rapidly urbanizing

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Why ecology of urbanization?

• Growing interest in designing liveable cities

Images from http//www.smartgrowthamerica.com/
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Why ecology of urbanization?
Baltimore Ecosystem Study
Central Arizona Phoenix Study

• New research initiatives to understand ecological
  processes in cities

Map from http//lternet.edu/sites/
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Key question How does landuse change alter
ecosystem processes?
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Hydrology
Figure from Christopherson, Geosystems (5th
edition), Prentice-Hall, 2003
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Hydrology

• Vegetation removal
• Impervious surfaces
• Artificial drainage structures

Graphic provided by Center For Watershed
Protection http//www.cwp.org/
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Hydrology

• Reduction in evapotranspiration
• Reduction in infiltration / soil moisture storage
• Increase in surface runoff
• Increased efficiency in drainage

Graphic provided by Center For Watershed
Protection http//www.cwp.org/
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Hydrology

• Rapid response to runoff (high velocity
  streamflow)
• Increase in flood peaks
• Reduction in baseflow

Figure from Christopherson, Geosystems (5th
edition), Prentice-Hall, 2003
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Hydrology

• Changes in frequency and magnitude of floods

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Geomorphology..
Hydraulic geometry of river channels
Figure from Christopherson, Geosystems (5th
edition), Prentice-Hall, 2003
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Geomorphology..
Profile
Changes in --
Cross-section
Planform
Figures from Christopherson, Geosystems (5th
edition), Prentice-Hall, 2003
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Riparian zones ..

• Filter nutrients and pollutants
• Provide thermal cover (shading)
• Enhance streambank stability

Figure from Christopherson, Geosystems (5th
edition), Prentice-Hall, 2003
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The urban atmosphere ..

• Aerodynamics
• Albedo (surface reflectance)
• Particulates and gases

Figure from Christopherson, Geosystems (5th
edition), Prentice-Hall, 2003
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The urban atmosphere ..

• Urban heat island effect

Figure from Christopherson, Geosystems (5th
edition), Prentice-Hall, 2003
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Biogeochemical cycles ..
Carbon

• Stores
• Vegetation
• Soil
• Biota
• Structures
• Fluxes
• Fire
• Fossil fuel combustion

Figure from Christopherson, Geosystems (5th
edition), Prentice-Hall, 2003
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Biogeochemical cycles ..
Nitrogen

• Sources
• Fixation
• Deposition
• Decomposition
• Transformations
• Mineralization
• Nitrification
• Immobilization (plant uptake)
• Assimilation
• Denitrification
• Leaching to streams

Figure from Don Ross, UVM Plant Soil Science
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Habitat ..
Figures from Christopherson, Geosystems (5th
edition), Prentice-Hall, 2003
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So how do we pull all this together?
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Appreciate process complexity and process
interactions
Figure from Christopherson, Geosystems (5th
edition), Prentice-Hall, 2003
across multiple spatial scales
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Consider models of ecosystem behavior
Figure from http//www.ntsg.umt.edu/ecosystem_mode
ling/BiomeBGC/default.htm
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Consider social processes
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What it all boils down to . A geographical
perspective
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So how do I know if this seminar is right for me?
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This seminar is designed for students

• with some background in physical geography, earth
  science or ecology
• interested in a discussion-oriented format
• with time to commit at least four hours per week
  to out-of-class preparation
• willing to work in groups, learn from each other,
  participate actively