Abstract
Urban trees are getting increasing attention as a tool to mitigate urban heat island effects. A more functional and quantitative view of transpirational and shading effect, particularly the magnitude of both surface and air cooling potential can further strengthen motivations for urban tree planting. We investigated the transpirational and the surface cooling potential of two contrasting tree species in Munich, Germany: ring porous Robinia pseudoacacia L. and diffuse porous Tilia cordata Mill. Throughout the summer 2016 we monitored meteorological and edaphic variables and tree sap-flow along with the air temperature within and outside tree shade at different heights. With 30% higher leaf area index (LAI), double sap-flux density and sapwood area, T. cordata trees showed three times higher transpiration compared to the R. pseudoacacia. Consequently, T. cordata trees showed higher within canopy air cooling effect. Surface cooling (∆Tshade) were higher under the denser canopies of T. cordata compared to R. pseudoacacia for asphalt surfaces but ∆Tshade for grass surfaces were not significantly different under the canopies of two species. Linear regression indicated a decrease in grass surface temperature of 3 °C with every unit of LAI but for asphalt, the reduction in surface temperature was about 6 °C. Additionally, higher water using efficiencies of R. pseudoacacia coupled with higher soil moisture and radiation probably increased the grass evapotranspiration and subsequently showed positive relationship with the near ground air cooling. Therefore, species with higher canopy density might be preferred over asphalt surfaces but low water using species with lower canopy density could be chosen over grass surfaces.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Armson D, Stringer P, Ennos AR (2012) The effect of tree shade and grass on surface and globe temperatures in an urban area. Urban For Urban Green 11:245–255
Armson D, Rahman MA, Ennos AR (2013) A comparison of the shading effectiveness of five different street tree species in Manchester, UK. Arboricult Urban For 39:157–164
Arnfield AJ (2003) Two decades of urban climate research: a review of turbulence, exchanges of energy and water, and the urban heat island. Int J Climatol 23:1–26. https://doi.org/10.1002/joc.859
Atkinson CJ, Taylor JM (1996) Effects of elevated CO2 on stem growth, vessel area and hydraulic conductivity of oak and cherry seedlings. New Phytol 133:617–626. https://doi.org/10.1111/j.1469-8137.1996.tb01930.x
Baldocchi DD, Vogel CA (1996) Energy and CO2 flux densities above and below a temperate broad-leaved forest and a boreal pine forest. Tree Physiol 16:5–16
Banerjee T, Linn R (2018) Effect of vertical canopy architecture on transpiration, thermoregulation and carbon assimilation. Forests 9. https://doi.org/10.3390/f9040198
Bartens J, Day SD, Harris JR, Wynn TM, Dove JE (2009) Transpiration and root development of urban trees in structural soil Stormwater reservoirs. Environ Manag 44:646–657. https://doi.org/10.1007/s00267-009-9366-9
Baureferat München (2016) Available at: http://www.muenchen.de/stadtteile/riem.html. Accessed 14 May 2017
Bowler DE, Buyung-Ali L, Knight TM, Pullin AS (2010) Urban greening to cool towns and cities: a systematic review of the empirical evidence. Landsc Urban Plan 97:147–155. https://doi.org/10.1016/j.landurbplan.2010.05.006
Bush SE, Pataki DE, Hultine KR, West AG, Sperry JS, Ehleringer JR (2008) Wood anatomy constrains stomatal responses to atmospheric vapor pressure deficit in irrigated, urban trees. Oecologia 156:13–20. https://doi.org/10.1007/s00442-008-0966-5
Cermak J, Nadezhdina N (1998) Sapwood as the scaling parameter defining according to xylem water content or radial pattern of sap flow? Ann Sci For 55:509–521. https://doi.org/10.1051/forest:19980501
Close RE, Kielbaso JJ, Nguyen PV, Schutzki RE (1996) Urban vs natural sugar maple growth:II. Water Relations. J Arboric 22:187–192
Dahlhausen J, Biber P, Rotzer T, Uhl E, Pretzsch H (2016) Tree species and their space requirements in six urban environments worldwide. Forests 7. https://doi.org/10.3390/f7060111
DWD (2017) Deutscher Wetterdienst
FAO (2009) ET0 calculator. Land and water digital media series, no. 36. FAO, Rome
Georgi JN, Dimitriou D (2010) The contribution of urban green spaces to the improvement of environment in cities: case study of Chania, Greece. Build Environ 45:1401–1414. https://doi.org/10.1016/j.buildenv.2009.12.003
Gill SE, Handley JF, Ennos AR, Pauleit S (2007) Adapting cities for climate change: the role of the green infrastructure. Built Environ 33:115–133
Gill SE, Rahman MA, Handley JF, Ennos AR (2013) Modelling water stress to urban amenity grass in Manchester UK under climatechange and its potential impacts in reducing urban cooling. Urban For Urban Green 12:350–358
Gillner S, Vogt J, Tharang A, Dettmann S, Roloff A (2015) Role of street trees in mitigating effects of heat and drought at highly sealed urban sites. Landsc Urban Plan 143:33–42. https://doi.org/10.1016/j.landurbplan.2015.06.005
Granier A (1987) Evaluation of transpiration in a Douglas-fir stand by means of sap flow measurements. Tree Physiol 3:309–319
Hardin PJ, Jensen RR (2007) The effect of urban leaf area on summertime urban surface kinetic temperatures: A Terre Haute case study. Urban For Urban Green 6. https://doi.org/10.1016/j.ufug.2007.01.005
Jiao L, Lu N, Fu B, Gao G, Wang S, Jin T, Zhang L, Liu J, Zhang D (2016a) Comparison of transpiration between different aged black locust (Robinia pseudoacacia) trees on the semi-arid loess plateau, China. J Arid Land 8:604–617. https://doi.org/10.1007/s40333-016-0047-2
Jiao L, Lu N, Sun G, Ward EJ, Fu BJ (2016b) Biophysical controls on canopy transpiration in a black locust (Robinia pseudoacacia) plantation on the semi-arid loess plateau, China. Ecohydrology 9:1068–1081. https://doi.org/10.1002/eco.1711
Katul GG, Mahrt L, Poggi D, Sanz C (2004) One- and two-equation models for canopy turbulence. Bound-Layer Meteorol 113:81–109. https://doi.org/10.1023/B:BOUN.0000037333.48760.e5
Keresztesi B (1988) The black locust. Akadémiai Kiadó, Budapest
Kong FH, Yan W, Zheng G, Yin H, Cavan G, Zhan W, Zhang N, Cheng L (2016) Retrieval of three-dimensional tree canopy and shade using terrestrial laser scanning (TLS) data to analyze the cooling effect of vegetation. Agric For Meteorol 217:22–34. https://doi.org/10.1016/j.agrformet.2015.11.005
Kume T, Otsuki K, Du S, Yamanaka N, Wang YL, Liu GB (2012) Spatial variation in sap flow velocity in semiarid region trees: its impact on stand-scale transpiration estimates. Hydrol Process 26:1161–1168. https://doi.org/10.1002/hyp.8205
Lee SH, Park SU (2008) A vegetated urban canopy model for meteorological and environmental modelling. Bound-Layer Meteorol 126:73–102. https://doi.org/10.1007/s10546-007-9221-6
Lin B-S, Lin Y-J (2010) Cooling effect of shade trees with different characteristics in a subtropical Urban Park. Hortscience 45:83–86
Lindberg F, Grimmond CSB (2011) The influence of vegetation and building morphology on shadow patterns and mean radiant temperatures in urban areas: model development and evaluation. Theor Appl Climatol 105:311–323. https://doi.org/10.1007/s00704-010-0382-8
Lindén J, Fonti P, Esper J (2016) Temporal variations in microclimate cooling induced by urban treesin Mainz, Germany. Urban For Urban Green 20:198–209
Moser A, Rahman MA, Pretzsch H, Pauleit S, Rotzer T (2017) Inter- and intraannual growth patterns of urban small-leaved lime (Tilia cordata mill.) at two public squares with contrasting microclimatic conditions. Int J Biometeorol 61:1095–1107. https://doi.org/10.1007/s00484-016-1290-0
Moser-Reischl A, Rahman MA, Pretzsch H, Pauleit S, Rötzer T (2019) Growth patterns and effects of urban micro-climate on two physiologically. Landsc Urban Plan 183: 88–99. https://doi.org/10.1016/j.landurbplan.2018.11.004
Oke TR (1989) The Micrometeorology of the Urban Forest. Philos Trans R Soc Lond Ser B-Biol Sci 324:335–349. https://doi.org/10.1098/rstb.1989.0051
Pataki DE, Oren R (2003) Species differences in stomatal control of water loss at the canopy scale in a mature bottomland deciduous forest. Adv Water Resour 26:1267–1278. https://doi.org/10.1016/j.advwatres.2003.08.001
Pataki DE, McCarthy HR, Litvak E, Pincetl S (2011) Transpiration of urban forests in the Los Angeles metropolitan area. Ecol Appl 21:661–677. https://doi.org/10.1890/09-1717.1
Pauleit S (2003) Urban street tree plantings: indentifying the key requirements. Proc Inst Civ Eng Munic Eng 156:43–50
Pauleit S, Duhme F (2000) Assessing the environmental performance of land cover types for urban planning. Landsc Urban Plan 52:1–20. https://doi.org/10.1016/s0169-2046(00)00109-2
Pauleit S, Jones N, Garcia-Martin G, Garcia-Valdecantos JL, Rivière LM, Vidal-Beaudet L, Bodson M, Randrup TB (2002) Tree establishment practice in towns and cities: results from a European survey. Urban For Urban Green 1:83–96. https://doi.org/10.1078/1618-8667-00009
Peters EB, McFadden JP, Montgomery RA (2010) Biological and environmental controls on tree transpiration in a suburban landscape. J Geophys Res Biogeosci 115. https://doi.org/10.1029/2009jg001266
Pongracz R, Bartholy J, Dezsoe Z (2010) Application of remotely sensed thermal information to urban climatology of central European cities. Phys Chem Earth 35:95–99. https://doi.org/10.1016/j.pce.2010.03.004
Qiu GY, Li HY, Zhang QT, Chen W, Liang XJ, Li XZ (2013) Effects of evapotranspiration on mitigation of urban temperature by vegetation and urban agriculture. J Integr Agric 12:1307–1315. https://doi.org/10.1016/s2095-3119(13)60543-2
R Core Team (2015) R: A language and environment for statistical computing. RFoundation for Statistical Computing, Vienna, Austria
Radoglou K, Dobrowolska D, Spyroglou G, Nicolescu V-N (2009) A review on the ecology and silviculture of limes (Tilia cordata Mill., Tilia platyphyllos Scop. and Tilia tormentosa Moench.) in Europe die. Bodenkultur 60:9–19
Rahman MA, Smith JG, Stringer P, Ennos AR (2011) Effect of rooting conditions on the growth and cooling ability of Pyrus calleryana. Urban For Urban Green 10:185–192. https://doi.org/10.1016/j.ufug.2011.05.003
Rahman MA, Stringer P, Ennos AR (2013) Effect of pit design and soil composition on performance of Pyrus calleryana street trees in the establishment period. Arboricult Urban For 39:256–266
Rahman MA, Armson D, Ennos AR (2015) A comparison of the growth and cooling effectiveness of five commonly planted urban tree species. Urban Ecosystems 18:371–389
Rahman MA, Moser A, Rötzer T, Pauleit S (2017a) Microclimatic differences and their influence on transpirational cooling of Tilia cordata in two contrasting street canyons in Munich, Germany. Agric For Meteorol 232:443–456
Rahman MA, Moser A, Rötzer T, Pauleit S (2017b) Within canopy temperature differences and cooling ability of Tilia cordata trees grown in urban conditions. Build Environ 114:118–128
Rahman MA, Moser A, Gold A, Rötzer T, Pauleit S (2018) Vertical air temperature gradients under the shade of two contrasting urban tree species during different types of summer days. Sci Total Environ 633:100–111
Renaud V, Rebetez M (2009) Comparison between open-site and below-canopy climatic conditions in Switzerland during the exceptionally hot summer of 2003. Agric For Meteorol 149:873–880. https://doi.org/10.1016/j.agrformet.2008.11.006
Roloff A (2013) Bäume in der Stadt. Ulmer, Stuttgart
Savi T, Bertuzzi S, Branca S, Tretiach M, Nardini A (2015) Drought-induced xylem cavitation and hydraulic deterioration: risk factors for urban trees under climate change? New Phytol 205:1106–1116. https://doi.org/10.1111/nph.13112
Shahidan MF (2015) Potential of individual and cluster tree cooling effect performances through tree canopy density model evaluation in improving urban microclimate. Curr World Environ 10:398–413
Shashua-Bar L, Pearlmutter D, Erell E (2009) The cooling efficiency of urban landscape strategies in a hot dry climate. Landsc Urban Plan 92:179–186. https://doi.org/10.1016/j.landurbplan.2009.04.005
Simonin KA, Burns E, Choat B, Barbour MM, Dawson TE, Franks PJ (2015) Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf. J Exp Bot 66:1303–1315. https://doi.org/10.1093/jxb/eru481
Smithers RJ, Doick KJ, Burton A, Sibille R, Steinbach D, Harris R, Groves L, Blicharska M (2018) Comparing the relative abilities of tree species to cool the urban environment. Urban Ecosystems 21:851–862. https://doi.org/10.1007/s11252-018-0761-y
Staas L, Beaumont L, Leishman M (2017) Which plant where: what we heard: documenting the stakeholder workshops. In: Urban Ecology Renewal Investigation project.
Stratopoulos LMF, Duthweiler S, Haberle KH, Pauleit S (2018) Effect of native habitat on the cooling ability of six nursery-grown tree species and cultivars for future roadside plantings. Urban For Urban Green 30:37–45. https://doi.org/10.1016/j.ufug.2018.01.011
Tyree MT, Zimmerman MH (2002) Xylem structure and the ascent of sap. Springer, New York
Vico G, Revelli R, Porporato A (2014) Ecohydrology of street trees: design and irrigation requirements for sustainable water use. Ecohydrology 7:508–523. https://doi.org/10.1002/eco.1369
Vitkova M, Muellerova J, Sadlo J, Pergl J, Pysek P (2017) Black locust (Robinia pseudoacacia) beloved and despised: a story of an invasive tree in Central Europe. For Ecol Manag 384:287–302. https://doi.org/10.1016/j.foreco.2016.10.057
von Arx G, Pannatier EG, Thimonier A, Rebetez M (2013) Microclimate in forests with varying leaf area index and soil moisture: potential implications for seedling establishment in a changing climate. J Ecol 101:1201–1213. https://doi.org/10.1111/1365-2745.12121
Wilby RL (2003) Past and projected trends in London's urban heat island. Weather 58:251–260
Xu C, Haase D, Pauleit S (2018) The impact of different urban dynamics on green space availability: a multiple scenario modeling approach for the region of Munich, Germany. Ecol Indic 93:1–12. https://doi.org/10.1016/j.ecolind.2018.04.058
Yang X, Zhao L (2016) Diurnal thermal behavior of pavements, vegetation, and water pond in a hot-Humid City. Buildings 6(1). https://doi.org/10.3390/buildings6010002
Zhang W, He K, Zhou Y, Deng J, Gan X (2007) Study on soil evaporation of the Robinia pseudoacacia forest land in semi-arid region of the Loess Plateau. Research of Soil and Water Conservation 14:367–370
Zhao L, Lee X, Smith RB, Oleson K (2014) Strong contributions of local background climate to urban heat islands. Nature 511:216–21+. https://doi.org/10.1038/nature13462
Zölch T, Maderspacher J, Wamsler C, Pauleit S (2016) Using green infrastructure for urban climate-proofing: an evaluation of heat mitigation measures at the micro-scale. Urban For Urban Green 20:305–316. https://doi.org/10.1016/j.ufug.2016.09.011
Acknowledgements
This study was carried out while the corresponding author was in receipt of an Alexander von Humboldt Fellowship and grant from TREE Fund (#: 15-JK-01). There was no involvement of the sponsors in study design; in the collection, analysis and interpretation of data; in writing the report; and in the decision to submit the article for publication. The authors want to thank the department for the municipal green areas of Munich, Dr. Bernhard Förster; Mrs. Anna Brähler; Mr. Chao Xu for their kind help.
Author information
Authors and Affiliations
Corresponding author
Additional information
Highlights
• Species differences and growth conditions can influence tree cooling potential
• Higher water transpiring species provided higher air cooling at the canopy height
• Higher leaf area index (LAI) provided better surface cooling over built surfaces
• Lower LAI and water demand showed better grass surface and near ground air cooling
Appendix
Appendix
Equation 1 Granier’s empirical calibration equation (Granier 1987)
where ��TM is the maximum temperature difference when sap flow is assumed to be zero.
Equations 2 and 3 the sap flow (SF) (ml tree−1 min−1) for T. cordata (Eq. 2) and R. pseudoacacia (Eq. 3) were estimated by multiplying sap flux density (Js; ml cm−2 min−1) with sap wood area (SA) following Rahman et al. (2017a)
Equation 4 SF were converted to daily values (average values between 9 am and 6 pm) and multiplied by the latent heat of vaporization LV which is 2.45 kJ g−1 to calculate the energy loss (W tree−1) per tree according to Eq. (4)
Rights and permissions
About this article
Cite this article
Rahman, M.A., Moser, A., Rötzer, T. et al. Comparing the transpirational and shading effects of two contrasting urban tree species. Urban Ecosyst 22, 683–697 (2019). https://doi.org/10.1007/s11252-019-00853-x
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11252-019-00853-x