Abstract
Urban vegetation can mitigate increases in summer air temperature by reducing the solar gain received by buildings. To quantify the temperature-moderating influence of city trees and vine-covered buildings, a total of 13 pairs of temperature loggers were installed on the surfaces of eight buildings in downtown Toronto, Canada, for 6 months during the summer of 2008. One logger in each pair was shaded by vegetation while the other measured built surface temperature in full sunlight. We investigated the temperature-moderating benefits of solitary mature trees, clusters of trees, and perennial vines using a linear-mixed model and a multiple regression analysis of degree hour difference. We then assessed the temperature-moderating effect of leaf area, plant size and proximity to building, and plant location relative to solar path. During a period of high solar intensity, we measured an average temperature differential of 11.7 °C, with as many as 10–12 h of sustained cooler built surface temperatures. Vegetation on the west-facing aspect of built structures provided the greatest temperature moderation, with maximum benefit (peak temperature difference) occurring late in the afternoon. Large mature trees growing within 5 m of buildings showed the greatest ability to moderate built surface temperature, with those growing in clusters delivering limited additional benefit compared with isolated trees. Perennial vines proved as effective as trees at moderating rise in built surface temperature to the south and west sides of buildings, providing an attractive alternative to shade trees where soil volume and space are limited.
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References
Akbari H, Konopacki S (2004) Energy effects of heat-island reduction strategies in Toronto, Canada. Energy 29:191–210
Akbari H, Taha H (1992) The impact of trees and white surfaces on residential heating and cooling energy use in four Canadian cities. Energy 17:141–149
Akbari H, Kurn DM, Bretz SE, Hanford JW (1997) Peak power and cooling energy savings of shade trees. Energy Build 25:139–148
Akbari H, Pomerantz M, Taha H (2001) Cool surfaces and shade trees to reduce energy use and improve air quality in urban areas. Sol Energy 70:295–310
Brown R, Gillespie T (1995) Microclimatic landscape design: creating thermal comfort and energy efficiency. Wiley, New York
Carver AD, Danskin SD, Zaczek JJ, Mangun JC, Williard K (2004) A GIS methodology for generating riparian tree planting recommendations. North J Appl For 21:100–106
Chatfield C (2003) The analysis of time series: an introduction. Chapman & Hall/CRC, New York
Chen WY, Jim CY (2008) Assessment and valuation of the ecosystem services provided by urban forests. In: Ecology, planning, and management of urban forests international perspective. Springer, New York, pp 53–83
Craul PJ (1992) Urban soil in landscape design. Wiley, New York
Craul PJ (1999) Urban soils: applications and practices. Wiley, New York
Delta-T Devices (1999) Hemiview user manual v2.1. http://dynamax.com/Manuals/HemiView_Manual.pdf. Accessed 4 Aug 2012
Donovan G, Butry D (2009) The value of shade: estimating the effect of urban trees on summertime electricity use. Energy Build 41:662–668
Federer CA (1976) Trees modify the urban microclimate. J Arboric 2:121–127
Fountain M, Brager G, de Dear R (1996) Expectations of indoor climate control. Energy Build 24:179–182
Grimm NB, Faeth SH, Golubiewski NE, Redman CL, Wu J, Bai X, Briggs JM (2008) Global change and the ecology of cities. Science 319:756–760
Hamin EM, Gurran N (2009) Urban form and climate change: balancing adaptation and mitigation in the US and Australia. Habitat Int 33:238–245
Hildebrandt EW, Sarkovich M (1998) Assessing the cost-effectiveness of SMUD’S shade tree program. Atmos Environ 32:85–94
Huang YJ, Akbari H, Taha H, Rosenfeld AH (1987) The potential of vegetation in reducing summer cooling loads in residential buildings. J Clim Appl Meteorol 26:1103–1116
Jim CY (2001) Managing urban trees and their soil envelopes in a contiguously developed city environment. Environ Manag 28:819–832
Jim WY, Chen CY (2009) Ecosystem services and valuation of urban forests in China. Cities 26:187–194
Kenney WA (2000) Lead area density as an urban forestry planning and management tool. Forest Chron 76:235–239
Kershaw SE, Millward AA (2012) A spatio-temporal index for heat vulnerability assessment. Environ Monit Assess 184:7329–7342
Littell RC, Milliken GA, Stroup WW, Wolfinger RD, Schabenberger O (2006) SAS for mixed models, 2nd edn. SAS Publishing, Cary
Lohr VI, Pearson-Mims CH, Tarnai J, Dillman DA (2004) How urban residents rate and rank the benefits and problems associated with trees in cities. J Arboric 30:28–35
McCarthy MP, Best MJ, Betts RA (2010) Climate change in cities due to global warming and urban effects. Geophys Res Lett 37:L09705
McPherson EG (1984) Energy-conserving site design. American Society of Landscape Architects, Washington, DC
McPherson EG, Dougherty E (1989) Selecting trees for shade in the southwest. J Arboric 15:35–43
McPherson EG, Rowntree RA (1993) Energy conservation potential of urban tree planting. J Arboric 19:321
McPherson EG, Nowak D, Heisler G, Grimmond S, Souch C, Grant R, Rowntree RA (1997) Quantifying urban forest structure, function, and value: the Chicago Urban Forest Climate Project. Urban Ecosyst 1:49–61
McPherson EG, Simpson JR, Peper PJ, Garder SL, Vargas KE, Maco SE, Xiao Q (2006) Piedmont community tree guide: benefits, costs, and strategic planting. USDA Forest Service General Technical Report PSW-GTR-200. USDA Forest Service, Davis
Miller RW (1997) Urban forestry: planning and managing urban greenspaces, 2nd edn. Prentice Hall, Englewood Cliffs
Millward AA, Sabir S (2010) Structure of a forested urban park: implications for strategic management. J Environ Manag 91:2215–2224
Millward AA, Sabir S (2011) Benefits of a forested urban park: what is the value of Allan Gardens to the city of Toronto, Canada? Landsc Urban Plan 100:177–188
Nowak DJ (1996) Estimating leaf area and leaf biomass of open-grown deciduous urban trees. For Sci 42:504–507
Oke TR (1973) City size and the urban heat island. Atmos Environ (1967) 7:769–779
Oke TR (1978) Boundary layer climates. Methuen & Co, London
Ontario Power Authority (2005) Factor analysis of Ontario electricity use 1990–2003. http://www.powerauthority.on.ca. Accessed 12 May 2012
Parker JH (1983) Landscaping to reduce the energy used in cooling buildings. J For 81:82–105
Rosenzweig C, Solecki WD, Slosberg R (2006) Mitigating New York City’s heat island with urban forestry, living roofs, and light surfaces. A report to the New York State Energy Research and Development Authority. http://www.fs.fed.us/ccrc/topics/urban-forests/docs/NYSERDA_heat_island.pdf. Accessed 20 Sep 2012
SAS/STAT Software (2012) SAS/STAT user’s guide. http://support.sas.com/documentation/onlinedoc/stat/. Accessed 10 Dec 2012
Sawka M, Millward AA, Mckay J, Sarkovich M (2013) Growing summer energy conservation through residential tree planting. Landsc Urban Plan 113:1–9
Simpson JR, McPherson EG (1996) Potential of tree shade for reducing residential energy use in California. J Arboric 22:10–18
Statistics Canada (2009) Spending patterns in Canada 2009. http://www.statcan.gc.ca/pub/62-202-x/62-202-x2008000-eng.pdf. Accessed 15 Dec 2012
Streutker DR (2003) Satellite-measured growth of the urban heat island of Houston, Texas. Remote Sens Environ 85:282–289
Sumida AA, Komiyama A (1997) Crown spread patterns for five deciduous broad-leaved woody species: ecological significance of the retention patterns of larger branches. Ann Bot 80:759–766
Voogt JA, Oke TR (2003) Thermal remote sensing of urban climates. Remote Sens Environ 86:370–384
Acknowledgments
We would like to acknowledge three anonymous reviewers for their comments helped to improve an earlier version of this manuscript. Financial assistance from Ryerson University’s Environmental Applied Science and Management Program supported the purchase of equipment. Preparation of this manuscript was aided with a grant provided by the office of the Dean of Arts, Ryerson University. Anna Bowen gave editorial assistance during the writing of this manuscript.
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Millward, A.A., Torchia, M., Laursen, A.E. et al. Vegetation Placement for Summer Built Surface Temperature Moderation in an Urban Microclimate. Environmental Management 53, 1043–1057 (2014). https://doi.org/10.1007/s00267-014-0260-8
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DOI: https://doi.org/10.1007/s00267-014-0260-8