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Urban ecology


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This is an updated version of the Urban Ecology slides that I discussed with my Soil and Water Conservation class at Western Illinois University

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Urban ecology

  1. 1. ~75% farmland > 50% corn + soy Its time to think PINK!
  2. 2. Why should we care about cities?
  3. 3. Urban areas depend on the productive and assimilative capacities of ecosystems far beyond their formal boundaries, i.e., land tens to hundreds of times larger than the area cities physically occupy are required to produce the energy, material goods, and nonmaterial services (including waste absorption) that sustain cities.
  4. 4. Intense urban population growth has occurred over the past century. Urban areas occupy a small area (< 3% of land) yet their impact is large, with ~80% of global C emissions, ~80% of global wood use and ~60% of global residential water use occurring in cities. (Grimm et al., 2008) Land use change directly associated with building cities as well as supporting the demands of urban populations drives many types of environmental change.
  5. 5. Some people have lived in cities for a long time but most people have NOT lived in cities. Do you recognize any of these famous ancient cities? Ayutthaya (Thailand)Machu Pichu (Peru) Anthens (Greece) Cahokia (USA)
  6. 6. In 1800, only 3 percent of the global population lived in cities and only 1 city had more than 1 million people.
  7. 7. By 1900, ~14 percent of the global population lived in cities and ~ 15 cities had > 1 million people.
  8. 8. In 1950, 30 percent of the world's population lived in cities and the number of cities with over 1 million people had grown to 83.
  9. 9. In ~2008, for the first time ever, more people lived in cities than in rural areas and there were more than 400 cities with over 1 million people!
  10. 10. (Grimm et al., 2008) Global & US trends in urban and rural populations
  11. 11. Megacities in 2002
  12. 12. There are currently ~ 30 megacities with more than 10 million people!
  13. 13.
  14. 14. WHICH ARE THE LARGEST? WHY PUBLISHED POPULATIONS FOR MAJOR WORLD URBAN AREAS VARY SO GREATLY RL Forstall, RP Greene and JB Pick Abstract: Lists of the world’s largest urban areas according to population size are surprisingly inconsistent in standard reference sources. They even disagree about which city is the world’s largest. In this paper we first review the differences found in the population reporting of the twenty largest world urban areas by several unofficial sources and by the United Nations. We then demonstrate that variations in the populations and rankings stem primarily from differences in concepts and definitions, not from bad census counts or lack of basic information about the individual urban areas.
  15. 15. metropolitan area = a large urban nucleus together with adjacent areas with a high degree of economic and social integration city proper = an incorporated administrative district with specific boundaries beyond which urban development has often far overflowed 3 terms used to define urban areas urban agglomeration = a central city (or cities) surrounded by continuous urban areas
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  18. 18. Seattle 3) Chicago metro area 9.4 million 4) Philadelphia metro area 5.8 million 1) NY City metro area 18.7 million 5) Dallas-Fort Worth metro area 5.8 million 2) LA metro area 12.9 million Honolulu Puerto Rico but only 8 % lived in metro areas with populations > 1 million. 0 100 10,000 people per sq. mile In 2010, 81 % of Americans lived in cities…
  19. 19. Today, ~75 % of the people in industrialized countries live in urban areas and ~45% of the people in developing countries live in urban areas. It is expected that world population will be 70 percent urban by 2050!
  20. 20. More than 95% of the net increase in the global population during the 21st century is projected to occur in cities in developing countries
  21. 21. Almost 40 percent of city dwellers in developing countries (~ 1 billion people) live in slums
  22. 22. Variation in urban population density
  23. 23. If *ALL* the people on planet Earth lived at the density of one city, how large would that city be?
  24. 24. Pollen analysis has now established that Easter Island was almost totally forested until 1200 CE. The tree pollen disappeared from the record by 1650, and the statues stopped being made around that time Almost 900 of these giant stone sculptures were carved and transported - some weighing over 80 tons
  25. 25. Highly populated areas (yellow and red) consume hundreds to thousands of times their local NPP. Source: Imhoff and others 2004 Globally about 40% of NPP is consumed by people!!! What is NPP?
  26. 26. Recently, however, ecologists have begun collaborating with other scientists, planners, and engineers to understand and even redesign urban ecosystems. (Grimm et al., 2008) During the 20th century, most ecologists ignored urban areas with the result that ecological knowledge contributed little to solving urban environmental problems.
  27. 27. Serious ecological scientists are now studying cities!
  28. 28. As Phoenix urbanized, native Sonoran desert ecosystems were replaced by an “urban oasis” with both lush, watered lawns and managed desert-like landscapes. Scientists are investigating the household decision-making, perceptions, and priorities that result in more ecological vs. less ecological residential landscapes. Which house/landscape would you choose?
  29. 29. Throughout history, most cities have sprung up along rivers, and other water bodies because of the opportunities created by the available water. Within cities, water provides invaluable services (e.g., residential use, industrial use, transportation, sanitation and recreation but is also linked to serious challenges (flooding, tsunamis, subsidence, mosquito vectored disease). The highly modified streams, rivers, flood channels, canals and other hydrosystems in urban areas provide few of the ecosystem services associated with natural aquatic systems (e.g., filtering, flood control, temperature moderation, habitat…)
  30. 30. Low flow events also contribute to water pollution when automotive chemicals, pet wastes, lawn care chemicals, persistent organic pollutants (e.g., flame retardants) wash off urban surfaces Stormwater is conveyed separately from sewage in cities with relatively new infrastructure but older European and American cities have combined sewer and stormwater systems resulting in serious pollution events every time large rainfall events occur
  31. 31. How carefully do home owners apply fertilizers and pesticides? Dr. Bernards would be proud of how carefully I calibrated this spreader!
  32. 32. 30-40 million acres of lawn!
  33. 33. Residential lawns occupy > 20 million acres in the US. US lawn care industry annual revenue exceeds $40 billion. > $ 5 billion is spent on fertilizer for U.S. lawns. A typical power lawnmower pollutes as much in one hour as driving an automobile for 20 miles. ~60 thousand severe accidents result from lawnmower use in the US each year, as well as significant damage to human hearing. ~ 70 million pounds of pesticides are applied to lawns each year Some stats to consider
  34. 34. Benefits of Turfgrass • Erosion Control • Infiltration of water • Carbon sequestration • Noise reduction • Cooling • Oxygen production
  35. 35. Turf is a great surface for this activity!
  36. 36. Fun at the Farm!
  37. 37. Turf may be a good surface for this land use but what is the environmental cost?
  38. 38. Crocodile tourism might be a better land use 
  39. 39. What is the function of these lawns? Do the benefits exceed the costs?
  40. 40. New mowers produce much less pollution than old mowers!
  41. 41. Midwest states many spend $$$ mowing thousands of acres of roadside turf.
  42. 42. Scenic beauty Reduced mowing costs Wildlife/pollinator habitat Increased alertness of drivers Roadside plantings of prairie vegetation have many benefits!
  43. 43. INTRODUCTION The Illinois Department of Transportation (IDOT) has been interested in mapping roadside prairie since 1992. A formal request was made in 1998 by Rich Nowack to map prairie while traveling to other IDOT project areas, and as time allowed. IDOT’s justification for this project was to preserve prairie habitat, and limit accidental mowing and herbicide spraying of native prairie remnants. In 2000, IDOT made this project a priority. In the 2001 field season, a more detailed and systematic approach was taken to survey prairies in Illinois. This report and final GIS map is the result of the information gathered during the 2003 field season in IDOT District 4. Inventory of Roadside Prairies Illinois Department of Transportation District 4 Illinois Natural History Survey Center for Biodiversity Technical Report (4) 2004
  44. 44. Large cities are the most complex systems that humanity has ever created and represent both incredible efficiencies and failures LA’s Pregerson Interchange contains 5 levels and 9 miles of cloverleaf loops.
  45. 45. The CDC reports that more than 500,000 American children have significant levels of lead in their bodies 18 cities in Pennsylvania and 11 in New Jersey may have an even higher share of children with dangerously elevated levels of lead than does Flint, MI.
  46. 46. Where is the lead coming from?
  47. 47. The health department provided the city with 149 Galesburg addresses where the worst cases of lead occurred from 1992 to 2015. The city cross-indexed those addresses with its own database of Galesburg homes to determine that only 60 of those 149 homes had private lead water service lines. This evidence, along with what the health department’s inspectors found in homes, pointed to lead paint fragments and dust in homes as a larger contributor to the problem than lead water service lines.
  48. 48. Poor planning and governance = many problems Crime Congestion Air pollution Water pollution Poverty Corruption Inequity
  49. 49. Michigan Central Station in Detroit A symbol of urban blight
  50. 50. The Moroun family has spent more than $8 million replacing thousands of windows, restoring electricity and installing a freight elevator.
  51. 51. Cities with twice as many people consume LESS than twice as many resources
  52. 52. Farms, factories, large animals and cities tend to benefit from Economies of Scale
  53. 53. Are large farms more efficient than small farms? Match between management opportunities and management skill is what matters most
  54. 54. University of Minnesota data from 2016 showed the top 20% of farmers had an average net farm income of $197,000, while the bottom 20% had an average loss of $61,000. Drilling through the numbers, Robert Craven from the Center for Farm Financial Management at the University of Minnesota said the difference between the top 20% and bottom 20% of producers was not so much yield or cash price or even owned versus rented acres. The big difference came in expenses and hedging gains. Seed, fertilizer, chemicals and rent expenses for corn production in southern Minnesota differed from an average of $665 per acre for the top 20% producers to $863 per acre for the bottom 20% group -- a difference of about $200 per acre… and hedging gains in 2016 were $15,207 for the top group versus a loss of $7,176 for the bottom group. “It wasn't just the big guys making money," noted Craven. "When we looked at number of acres farmed, there wasn't much difference between the 1,000- to 1,500-acre producer and the 2,000- to 5,000-acre farmer in terms of net return. Farm size did not determine profitability. Cutting expenses and better marketing was a much bigger factor" Craven reported.
  55. 55. Elephants weigh ~10,000 times more than guinea pigs but only consume ~ 1000 times as many calories WHY? Slow metabolism High metabolism
  56. 56. Some cities are much more efficient than others!
  57. 57. A key concept within the discipline of urban ecology is urban metabolism which compares the flows of energy and materials in and out of cities and the transformation and accumulation of energy and materials within cities to biological metabolism. Some scientists debate the appropriateness of the metabolism analogy but interest in urban metabolism has led to informative analysis of long-term trends in the flow of energy, paper, plastics, metals and food stuffs in, out and within cities. What is urban metabolism?
  58. 58. Analysis of Toronto The metabolism of some cities has been intensively analyzed
  59. 59. After studying Australian ant colonies, mathematicians think ants might have something to teach us about network design, and how we evaluate priorities in the placement of schools, post offices and power plants, and the expansion of transportation systems. Models of ant colony growth, they believe, can be used to improve the design of human systems.
  60. 60. Many factors influence the metabolism of cities Sprawled, low-density cities have higher per capita transportation energy requirements than compact cities. Cities with interior continental climates expend more energy on winter heating and summer cooling than those with more temperate climates. Application of technology, appropriate use of vegetation and the costs of energy influence energy consumption. Public policies (e.g., building codes and recycling programs) and social attitudes impact material and energy flows. Lastly, the age of a city, the design of its infrastructure, and its stage of industrial development impact its urban metabolism.
  61. 61. (Gigajoules/year/person) 1 gallon of gasoline per day Do you consume > 1 gallon of gasoline per day? Adapted from (Newman and Kenworthy, 1991)
  62. 62. The City Solution Why cities are the best cure for our planet's growing pains December 2011
  63. 63. Large cities are concentrations of human ingenuity and generally require far fewer resources on a per capita basis than small towns or rural areas.
  64. 64. “Possibly the most exciting book on ecology or environmentalism to be published in years, David Owen's Green Metropolis: Why Living Smaller, Living Closer, and Driving Less Are the Keys to Sustainability challenges the conventional wisdom of the environmental movement and uses New York City (not Portland or rural Vermont) as a model of true sustainability. Owen's seemingly counter-intuitive argument is supported by the data: New Yorkers have the lowest per capita energy consumption and smallest per capita carbon footprint of anyone in the United States. The key to this isn't that New Yorkers are morally superior or ideologically predisposed to environmentalism, but simply the structure of the city: “Manhattan's density is approximately 67,000 people per square mile, or more than eight hundred times that of the nation as a whole and roughly thirty times that of Los Angeles.”
  65. 65. Perhaps most important, people in dense cities drive less. Their destinations are close enough to walk to, and enough people are going to the same places to make public transit practical. City dwellers tread more lightly in many ways, David Owen explains in Green Metropolis. Their roads, sewers, and power lines are shorter and so use fewer resources. Their apartments take less energy to heat, cool, and light than do houses.
  66. 66. New Delhi car ban yields trove of pollution data Scramble by researchers to monitor driving restrictions in Indian capital pays off. New Delhi, India may be the world’s most polluted city, but it’s making an effort to relinquish that title. With pollution from particulate matter at potentially lethal levels early last December, city officials took a drastic step: they announced that they would temporarily restrict the use of private vehicles by allowing owners to drive only on alternate days, based on the their number plates #s. The initial results of that 15-day trial, which began on 1 January, are now in. Although traffic actually increased in the first week of the ban, the levels of PM2.5 — particulate matter measuring less than 2.5 microns across — fell by roughly 10%. That is a victory not just for New Delhi officials, but also for the scientists who sprang into action to collect the data necessary to determine whether the test had achieved its goal.
  67. 67. In December 2015, daily levels of noxious PM2.5 in New Dehli ranged from 400–600 µg/m3 – much higher than the Indian legal standard of 60 µg/m3 (which itself is more than double the 25 µg/m3 target threshold set by the World Health Organization). Scientists predict that PM2.5 particles cause more than 600,000 premature deaths annually in India How serious is air pollution in New Dehli?
  68. 68. The high cost of suburban living is heavily subsidized by the rest of the population in the form of public funds spent on road construction, extension of utility lines, school buses and emergency services for new developments. If the true cost of sprawl were borne by developers and suburban home-buyers, in the form of increased housing prices, higher property taxes and infrastructure recovery costs (e.g., higher utility bills and tolls on roads primarily used by commuters) suburbs would be much more expensive places to live.
  69. 69. 1.7 million people 3.6 million people 2.9 million people100 people ??? million people What do you know about Chicago?
  70. 70. In the late 19th century, Chicago was a commercial colossus, a city growing more quickly than New York, flooded with industrial money but ravaged by great income disparities, lax health standards, and labor upheavals. For Chicago to become the city it could be, civic leaders recognized the need for urban planning, both to solve Chicago's existing problems and to prepare it for a prosperous future. The result was architect Daniel Burnham's 1909 plan for Chicago, a model of urban planning, aesthetic sophistication, and technical achievement.
  71. 71. Congress Parkway Arterial street widening Civic Center Chicago River straightening Roosevelt Road Grant Park Northerly Island New diagonal avenues Consolidated railroad stations Two-level riverfront drives Make no little plans. They have no magic to stir men’s blood and probably themselves will not be realized. Make big plans; aim high in hope and work, remembering that a noble, logical diagram once recorded will never die. D. Burnham
  72. 72. Chicago has a long history of big plans!
  73. 73. What happens to storm water in Chicago?
  74. 74. A very grand solution
  75. 75. The Thornton Reservoir is the final stage of the TARP tunnel project's Calumet branch. When the former limestone quarry fills, it will add 7.9 billion more gallons of capacity to Chicago’s stormwater runoff system.
  76. 76. Thorton Reservoir ~ 8 billion gallons!
  77. 77. “If you look around at major cities in the country, Chicago had so much foresight – and as a result is spending far less, and benefiting so much more than other cities,” says David St. Pierre, executive director of the Metropolitan Water Reclamation District in regard to efforts to keep storms from flooding cities.
  78. 78.  improving stormwater management by reducing runoff and improving water quality  reducing heating and cooling costs  increasing longevity of roofing membranes  reducing noise and air pollution  increasing urban biodiversity  providing space for urban agriculture  providing a more aesthetically pleasing and healthy environment to work and live
  79. 79. Chicago City Hall
  80. 80. LEED, or Leadership in Energy & Environmental Design, is a green building certification program that recognizes best-in-class building strategies and practices. To receive LEED certification, building projects satisfy prerequisites and earn points to achieve different levels of certification.
  81. 81. LEED v4 is bolder, more specialized, and designed for an improved user experience. There are 4 levels of certification
  82. 82. The WIU Multicultural Center is built to LEED 2.2 Silver criteria!
  83. 83. If what you value most is nature, cities look like concentrated piles of damage—until you consider the alternative, which is spreading the damage.
  84. 84. Cities allow more than half of humanity to live on <3% of the earth’s arable land, leaving more space for nature.
  85. 85. Positive human experiences with non-native, global “homogenizers”, such as pigeons, may be essential for convincing urbanites of the importance of conserving global biodiversity. With an ever-increasing fraction of humans living in cities, encounters with urban nature have supplanted experiences with natural biodiversity for many people.
  86. 86. Most Americans don’t like cities. In an annual Gallup poll, from 1966 to the present day, the number of Americans who have reported a preference for city living has never been higher than 20 percent. (The other options Gallup provides are small town, farm or suburb.) Steven Conn’s new book, Americans Against the City: Anti- Urbanism in the Twentieth Century analyzes the causes and effects of Americans’ anti-city sentiment. Despite all their benefits