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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
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Forestry & SocietyUrban Forestry HORT/RGSC 302 J.G. Mexal Spring 2001
2001 Pecan-ferenceThe 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 & SocietyUrban Forestry/urban areas J. For. 99:37-42:’01
Forestry & SocietyUrban Forestry/urban areas New York Chicago Oakland Baltimore Atlanta J. For. 99:37-42:’01
We like our space/ PNW Science Findings Developed land (ha/cap)
We like our space/ PNW Science Findings Developed land (1,000 ha)
Forestry & SocietyUrban Forestry/urban areas • Urban areas have lost 21% of forest cover in last 10 yrs • Satellite survey of 448 communities • Cost = $234 billion in health, environmental costs • Reco = plant 1.7 billion trees to replace 10% of those lost • Atlanta, GA= one of worst impacted http://www.cnn.com/2003/TECH/science/09/18/cities.trees.reut/index.html
Forestry & SocietyUrban Forestry/urban areas 251 trees/cap. 15 trees/cap 22 trees/cap 9 trees/cap 28 trees/cap 35 trees/cap J. For. 99:37-42:’01
“Urban Heat Island” effect for California counties / J.Am. Phy. & Sur. Tipping Point? County Population
Forestry & SocietyCost Effectiveness of Tree Planting/CA Maximum Planting Costs ($/tree) Urban Forestry Research, Oct’01)
Forestry & SocietyCost Effectiveness of Tree Planting/CA http://cufr.ucdavis.edu
Urban forestryRainfall Interception by Trees/ Urb.For. Res. Jul.’02) Interception (gal.) Projected Crown Area (ft2)
Forestry & SocietyControl Stormwater with Trees/Urban Forest Research 7/’02 Rainfall Interception/ 1/4” event (gal) Projected Crown Area (ft2)
Forestry & SocietyEffectiveness 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 • NO2 reduction: 26 kg/tree • O3 reduction: 10 kg/tree • PM10: 9 kg/tree • SO2: 2 kg/tree • Carbon Sequestration: 4.35 tons/tree • Decreased stormwater runoff: 50 gal/tree Total Benefit = $131,000,000 Urban Forestry Research, Oct’01)
Air Pollution Removed by Trees/Chicago Tons Month
Forestry & SocietyUrban 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 & SocietyUrban ForestryThe Value of Trees • Commensurable values • nut production • biomass production • Non-commensurable values • CO2 capture • O2 release • Pollution Control • Altered Microclimate • Beauty
Forestry & SocietyUrban ForestryCO2 capture Basic Photosynthetic Reaction • CO2 + H2O CH2O + O2 • 1.47 lb 0.60 lb 1.00 lb 1.07 lb λ
Forestry & SocietyUrban ForestryCO2 capture Basic Photosynthetic Reaction • CO2 + H2O CH2O + O2 • 1.47 lb 0.60 lb 1.00 lb 1.07 lb λ OM =0.42 Kernal = 0.16 Thinnings = 0.21 Fixed C = 0.21 Respired back to CO2
Forestry & SocietyUrban ForestryCO2 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 & SocietyUrban ForestryOxygen 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 & SocietyUrban ForestryPollutant 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 & SocietyUrban ForestryAltered 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.
Forestry & SocietyUrban ForestryAltered Microclimate Filtration Obstruction Guidance Deflection
Forestry & SocietyUrban ForestryAltered Microclimate 10X the tree height
Forestry & SocietyUrban Forestry/Windbreaks- Caborn 1957 Wind Flow through Windbreaks Loose Composition Dense composition
Forestry & SocietyUrban Forestry/Windbreaks- Geiger 1950 Loose Dense Very Dense
Forestry & SocietyUrban Forestry- Sound Attenuation/ Urban Forestry 1988
Forestry & SocietyUrban ForestryAltered Microclimate Reduce A/C ~9% $/25 ft tree McPherson & Rowntree ‘93
Forestry & SocietyUrban ForestryThe Value of Trees Conclusions: • The importance of trees in an urban environment includes environmental, aesthetic and cultural values.
Forestry & SocietyUrban 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?