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 J. For. 99:37-42:’01 Oakland Chicago Atlanta Baltimore New York

We like our space/ PNW Science Findings Developed land (ha/cap)

We like our space/ PNW Science Findings Developed land (1,000 ha)

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 Forestry & Society Urban Forestry/urban areas

Forestry & Society Urban Forestry/urban areas J. For. 99:37-42:’01 15 trees/cap 9 trees/cap 251 trees/cap. 35 trees/cap 22 trees/cap 28 trees/cap

“Urban Heat Island” effect for California counties / J.Am. Phy. & Sur. County Population Tipping Point?

Forestry & Society Cost Effectiveness of Tree Planting/CA Maximum Planting Costs ($/tree) Urban Forestry Research, Oct’01)

Tree SizeCommunity Value ($) Annual Value ($/yr) Small$960 over 60 yrs$16/yr Medium Large$4,440 over 120 yrs$37/yr Forestry & Society Cost Effectiveness of Tree Planting/CA

Urban forestry Rainfall Interception by Trees/ Urb.For. Res. Jul.’02) Projected Crown Area (ft 2 ) Interception (gal.)

Forestry & Society Control Stormwater with Trees/ Urban Forest Research 7/’02 Projected Crown Area (ft 2 ) Rainfall Interception/ 1/4” event (gal)

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 –NO 2 reduction: 26 kg/tree –O 3 reduction: 10 kg/tree –PM10: 9 kg/tree –SO 2 : 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 Month Tons

Forestry & Society Urban Forestry -- Biomass/ Kraimer, unpubl Roots = 362 kg/tree Trunk = 263 kg/tree Branches= 332 kg/tree (large) Branches= 209 kg/tree (small) Leaves = 64 kg/tree Husks = 10 kg/tree Pecans = 28 kg/tree Total= 1,270 kg/tree

Forestry & Society Urban Forestry The Value of Trees Commensurable values –nut production –biomass production Non-commensurable values –CO 2 capture –O 2 release –Pollution Control –Altered Microclimate –Beauty

Forestry & Society Urban Forestry CO 2 capture Basic Photosynthetic Reaction CO 2 + H 2 O CH 2 O + O lb 0.60 lb 1.00 lb1.07 lb λ

Forestry & Society Urban Forestry CO 2 capture Basic Photosynthetic Reaction CO 2 + H 2 O CH 2 O + O lb 0.60 lb 1.00 lb1.07 lb λ Kernal = 0.16 OM =0.42 Thinnings = 0.21 Fixed C = 0.21 Respired back to CO 2

Forestry & Society Urban Forestry CO 2 capture 1 tree captures 330 lb CO 2 (90 lb C) 1 acre captures about 6,600 lb CO 2 –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

Forestry & Society Urban Forestry Oxygen Release 1 acre of pecans:2.42 tons O 2 /yr 43,000 acres: 104,000 tons O 2 /yr One persons uses about 400 lb O 2 /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 0 3 –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 GuidanceDeflection

Forestry & Society Urban Forestry Altered Microclimate

10X the tree height

Forestry & Society Urban Forestry/Windbreaks- Caborn 1957 Dense composition Loose Composition Wind Flow through Windbreaks

Forestry & Society Urban Forestry/Windbreaks- Geiger 1950 Very Dense Dense Loose

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

Forestry & Society Urban Forestry Altered Microclimate $/25 ft tree McPherson & Rowntree ‘93 Reduce A/C ~9%

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 CO 2 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?