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Forestry _ Society Urban Forestry

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					 Forestry & Society
Urban Forestry
HORT/RGSC 302
  J.G. Mexal
  Spring 2001
2001 Pecan-ference
The Value of Trees/Pirone 2000
•   Supply Oxygen
•   Sequester Carbon Dioxide
•   Reduce Noise Pollution
•   Trap Particulates
•   Alter Microclimate
•   Improve Aesthetics
•   Enhance Outdoor Urban Spaces
•   Alter the Character of a Community
Forestry & Society
Urban Forestry/urban areas




                             J. For. 99:37-42:’01
Forestry & Society
Urban Forestry/urban areas                                                                        300
                                                                                                              New York
                                                                                                  200
                                                                                                  100
                                                                                                    0
                                                                                                          Tre e s Tre e s/ha   Tre e
    300
               Oakland                    300          Chicago                                          (x10000)               Cove r
                                                                                                                                (%)
    200                                   200
    100                                   100
      0                                     0
            Tre e s Tre e s/ha   Tre e            Tre e s Tre e s/ha   Tre e
          (x10000)               Cove r         (x10000)               Cove r
                                  (%)                                   (%)


                                                                                                                       Baltimore
                                                           300
                                                                        Atlanta                            300
                                                                                                           200
                                                           200                                             100
                                                           100                                               0
                                                              0                                                    Tre e s Tre e s/ha   Tre e
                                                                    Tre e s Tre e s/ha   Tre e                   (x10000)               Cove r
                                                                  (x10000)               Cove r                                          (%)
                                                                                          (%)




                                                                                                   J. For. 99:37-42:’01
    We like our space/ PNW Science Findings
Developed land (ha/cap)
    0.5

    0.4                                                          1982
                                                                 1997
    0.3

    0.2

    0.1

         0
              ains            we   st
                                        Sou
                                            th         est       est       est        east          rnia
         at Pl           outh                    M idw      M idw      rthw      orth        al ifo
   Gre               S                       So.        No.          No        N           C
     We like our space/ PNW Science Findings
Developed land (1,000 ha)
    1800
    1600
    1400                                                       1982-1997
    1200
    1000
     800
     600
     400
     200
       0
               ains            we   st
                                         Sou
                                             th         est       est       est        east          rnia
          at Pl           outh                    M idw      M idw      rthw      orth        al ifo
    Gre               S                       So.        No.          No        N           C
Forestry & Society
Urban Forestry/urban areas
• Urban areas have lost 21% of forest cover
  in last 10 yrs
   – Satellite survey of 448 communities
   – Cost = $234 billion in health, environmental
     costs
   – Reco = plant 1.7 billion trees to replace 10% of
     those lost
   – Atlanta, GA= one of worst impacted

            http://www.cnn.com/2003/TECH/science/09/18/cities.trees.reut/index.html
Forestry & Society
Urban Forestry/urban areas
               251 trees/cap.
15 trees/cap                    22 trees/cap


                  9 trees/cap                  28 trees/cap




                                35 trees/cap




                                               J. For. 99:37-42:’01
“Urban Heat Island” effect for California
counties / J.Am. Phy. & Sur.




          Tipping
          Point?



              County Population
 Forestry & Society
 Cost Effectiveness of Tree Planting/CA
    Mountains
     So Coast                $/tree
Central Coast
     No Coast
  South Valley
Inland Empire
Mid Ctr Valley
 No Ctr Valley
  High Desert
   Low Desert
 So Ctr Valley

                 0      40            80      120           160
                     Maximum Planting Costs ($/tree)
                                               Urban Forestry Research, Oct’01)
Forestry & Society
Cost Effectiveness of Tree
Planting/CA
Tree Size      Community Value       Annual Value
                    ($)                 ($/yr)
Small          $960 over 60 yrs          $16/yr
Medium
Large         $4,440 over 120 yrs        $37/yr


                           http://cufr.ucdavis.edu
Urban forestry
Rainfall Interception by Trees/
Urb.For. Res. Jul.’02)
Interception (gal.)
 140
 120
              Total (gal)
 100          Summer
  80          Winter

  60
  40
  20
   0
       0     200      400        600     800     1000    1200   1400
                            Projected Crown Area (ft2)
 Forestry & Society
 Control Stormwater with Trees/
 Urban Forest Research 7/’02
Rainfall Interception/ 1/4” event (gal)
  100
              Deciduous (summer)
   80         Evergreen (summer)
              Deciduous (winter)
   60         Evergreen (winter)

   40

   20

    0
        0      200        400      600    800   1000   1200   1400

                         Projected Crown Area (ft2)
Forestry & Society
Effectiveness of Tree Planting/CA
Trees for a Green LA will plant 200,000 trees
• Cost: $7,500,000
• Energy Savings: $10,500,000 (81 kw/tree/yr)
   – Cut cooling costs 15-35%
   – Cut heating costs 10-15%
• Air Quality Improvements
                                        Total Benefit =
   –   NO2 reduction: 26 kg/tree
   –   O3 reduction: 10 kg/tree
                                        $131,000,000
   –   PM10: 9 kg/tree
   –   SO2: 2 kg/tree
• Carbon Sequestration: 4.35 tons/tree
• Decreased stormwater runoff: 50 gal/tree   Urban Forestry Research, Oct’01)
 Air Pollution Removed by Trees/Chicago
Tons
600
                                           Ozone
500                                        Particulates
                                           NO2
400
                                           SO2
300                                        CO

200

100

  0
       J   F   M   A   M   J   J   A   S   O   N    D
                           Month
Forestry & Society
Urban Forestry -- Biomass/ Kraimer, unpubl
                              Pecans = 28 kg/tree
                              Husks    = 10 kg/tree
                              Leaves = 64 kg/tree
                              Branches= 209 kg/tree
                              (small)
                              Branches= 332 kg/tree
                              (large)

                              Trunk    = 263 kg/tree

                               Roots   = 362 kg/tree

                              Total=   1,270 kg/tree
Forestry & Society

Urban Forestry The Value of Trees
• Commensurable values
   – nut production
   – biomass production
• Non-commensurable values
   –   CO2 capture
   –   O2 release
   –   Pollution Control
   –   Altered Microclimate
   –   Beauty
Forestry & Society

Urban Forestry CO2 capture
Basic Photosynthetic Reaction

                     λ
• CO2 + H2O              CH2O + O2

• 1.47 lb 0.60 lb        1.00 lb   1.07 lb
Forestry & Society

Urban Forestry CO2 capture
Basic Photosynthetic Reaction

                            λ
• CO2 + H2O                           CH2O + O2

• 1.47 lb 0.60 lb                     1.00 lb   1.07 lb

    Kernal       OM =0.42       Thinnings        Fixed C
    = 0.16                          = 0.21        = 0.21
             Respired back to CO2
Forestry & Society

Urban Forestry CO2 capture
• 1 tree captures 330 lb CO2 (90 lb C)
• 1 acre captures about 6,600 lb CO2
   – value = $66/ac (@ $20/BDT)
   – balance = 7,500 vehicle miles
• 43,000 ac capture about 283,000,000 lb.
   – value = $2,838,000
   – balance = 21,000 vehicles (@15,000mi/vehicle)
Forestry & Society

Urban Forestry Oxygen Release
• 1 acre of pecans:       2.42 tons O2/yr
• 43,000 acres:        104,000 tons O2 /yr

• One persons uses about 400 lb O2/yr. Thus,
  NM WTx pecans supply enough oxygen for
  520,000 people!
Forestry & Society

Urban Forestry Pollutant Trapping
                                            /McPherson
• 1 tree traps 10 lb of pollutants
   – 4 lb 03
   – 3 lb particulates
• 1 ac of pecan traps 500 lb of pollutants
   – pollutants:
      • 200 lb ozone
      • 150 lb particulates
   – value: $2,250/ac in emission reduction credits
• 43,000 ac traps 10,750 tons of pollutants
   – value: $96,750,000 in E.R.C.
Forestry & Society

Urban Forestry Altered Microclimate
• Pecans leaf out late
  when homes may still
  need solar heat.
• Pecans defoliate late
  when homes may still
  need air conditioning.
• Save $20-30/home in
  A/C costs.
Benefits of windbreaks
Forestry & Society

Urban Forestry Altered Microclimate




Obstruction                Filtration




Guidance             Deflection
Forestry & Society

Urban Forestry Altered Microclimate
Forestry & Society

Urban Forestry Altered Microclimate




                     10X the tree height
Forestry & Society
Urban Forestry/Windbreaks- Caborn 1957
Wind Flow through Windbreaks

                               Loose Composition




                                  Dense composition
Forestry & Society

Agroforestry- Windbreaks/   Spurr 1964
Forestry & Society
Urban Forestry/Windbreaks- Geiger 1950



                Loose



                          Dense



                 Very Dense
Forestry & Society
Urban Forestry- Sound Attenuation/
                        Urban Forestry 1988
 Forestry & Society

 Urban Forestry Altered Microclimate


                                Reduce A/C ~9%
$/25 ft tree
   40

   30
                                                TotalSavings
   20
                                            Shade
   10                                   ET Cooling
                                     Wind Reduction
    0
         Tucson   Denver   Dallas
                                     McPherson & Rowntree ‘93
Forestry & Society

Urban Forestry The Value of Trees
Conclusions:
• The importance of trees in an urban
  environment includes environmental,
  aesthetic and cultural values.
Forestry & Society
Urban Forestry/Review Questions
• What benefit are trees in an urban environment?
• How are windbreaks useful? What do they do?
• What is the basic photosynthetic reaction? How
  much CO2 is removed from the atmosphere and
  how much oxygen is released for each pound of
  carbohydrates created?
• How many trees should you plant in your lifetime
  to meet your needs? Explain?
• How are trees in the landscape important?

				
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posted:9/6/2012
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