Article Figures & Data
Figures
- Figure 1.
Study area.
- Figure 2.
Research framework.
- Figure 3.
Hourly average variations of PET and other meteorological parameters observed among tree species.
- Figure 4.
Violin and boxplot graphs for tree parameters.
- Figure 5.
Scatter plot of PCA.
- Figure 6.
Cluster analysis.
- Figure S1.
Boxplot of distribution of air temperature (Ta), relative humidity (RH), wind velocity, and surface temperature (Surface T) under the tree and near exposed area.
Tables
Name of species Front view Sky view factor (SVF) Comments Plumeria obtuse (Araliya) 
Height 5 to 12 m Spread 5 to 9 m Crown shape Round; vase shape Crown density Open Growth rate Slow Leaf Simple and alternate leaf arrangement; elliptic (oval) leaf shape; leaf margin: entire, undulate Leaf type and persistence Evergreen Cassia fistula (Ehela) Height 3 to 9 m Spread 5 to 12 m Crown shape Oval; upright; vase shape Crown density Moderate Growth rate Fast Leaf Compound leaves, 10 to 60 cm long, 3 to 8 pairs of leaflets arranged in opposites, including the terminal pair; leaflets are oval-shaped, smooth, and shiny Leaf type and persistence Deciduous to semi-evergreen Mangifera indica (Mango) Height 9 to 18 m Spread 9 to 15 m Crown shape Round Crown density Dense Growth rate Fast Leaf Simple and alternate leaf arrangement; lanceolate to elongated-elliptic leaf shape; leaf margin: entire and undulate Leaf type and persistence Evergreen, broadleaf evergreen Terminalia catappa (Kottamba) Height 9 to 16 m Spread 9 to 15 m Crown shape Pyramidal, spreading, vase (mature trees) Crown density Moderate Growth rate Moderate Leaf Simple and alternate leaf arrangement; broadly obovate leaf shape; leaf margin: entire Leaf type and persistence Deciduous Tectona grandis (Teak) Height Up to 14 to 30 m in favourable conditions Spread Moderate Crown shape Rounded and open/umbrella Crown density Moderate Growth rate Fast Leaf Large and thick; simple and opposite Leaf type and persistence Deciduous - Table 2.
Specifications of the instruments used for the data collection. DBH (diameter at breast height).
Instrument Parameter Accuracy Smart sensor humidity and temperature meter Air temperature ± 1.5 °C Relative humidity ± 0.1% RH Smart sensor digital anemometer Wind velocity ± 0.1 m/s or ± 5% Solar power meter Solar radiation ± 10 W/m2 or ± 5% Infrared radiometer Surface temperature ± 0.3 °C Fisheye lens Sky view factor Measuring tape Tree crown diameter ± 0.1 m or ± 5% Circumference/DBH Range finder Tree height and tree trunk height ± 0.3 m Tree species Number of trees Number of total observations under the tree Number of total observations in exposed area Average PET under the tree (°C) Average PET in near exposed area (°C) Araliya 13 78 78 35.96 41.47 Ehela 14 84 84 34.72 40.21 Mango 15 90 90 34.52 40.13 Kottamba 14 84 84 34.24 40.08 Teak 14 84 84 35.81 41.42 Total 70 420 420 35.05 40.66 Ward/site Name Extent (km2) Green cover percentage in 2010 (%) 1 Bloemendhal (Colombo 13) 1.01 10.62 2 Fort (Colombo 1) 2.13 7.76 3 Wekanda (Colombo 2) 0.55 20.13 4 Bambalapitiya (Colombo 4) 1.48 21.23 5 Cinnamon Gardens (Colombo 7) 3.68 41.30 6 Thimbirigasyaya (Colombo 5) 1.88 43.00 Site Name of the ward Selected areas 1 Bloemendhal (Colombo 13) Sugathadasa indoor stadium
Sirimawo Bandaranaike Mawatha
2 Fort (Colombo 1) Chathum Street
Lotus Road
3 Wekanda (Colombo 2) Sir James Pieris Road
Jinarathana Mawatha
4 Bambalapitiya (Colombo 4) R. A. De Mel Mw (Duplication Road) 5 Cinnamon Gardens (Colombo 7) Bauddhaloka Mawatha
Green Path
Bandaranaike Memorial International Conference Hall
Vidya Mawatha
6 Thimbirigasyaya (Colombo 5) Thimbirigasyaya Road
Havelock Road
Site Name of the ward Number (no.) of trees Total no. of trees Mango Araliya Teak Kottamba Ehela 1 Bloemendhal 3 2 2 2 2 11 2 Fort 2 2 2 2 2 10 3 Wekanda 2 1 2 2 1 8 4 Bambalapitiya 2 2 2 2 3 11 5 Thimbirigasyaya 2 2 2 2 2 10 6 Cinnamon Gardens 4 4 4 4 4 20 Total no. of trees 15 13 14 14 14 70 - Table S4.
Descriptive comparison of physiological equivalent temperature (PET) between sunny and overcast conditions. No. (number of trees); SE mean (standard error of the mean); StDev (standard deviation); Min (minimum PET [°C]); Max (maximum PET [°C]).
Variable Weather No. Mean SE mean StDev Min Max PET (°C) (Under the tree) Overcast 177 32.42 0.287 3.816 23.5 45.2 Sunny 243 36.94 0.252 3.928 27.2 45.1 Ex-PET (°C) (Near-exposed area) Overcast 177 38.30 0.472 6.285 24.9 52.0 Sunny 243 42.35 0.240 3.738 29.0 49.5 - Table S6.
Analysis of variance (ANOVA) table of the regression analysis. DF (degrees of freedom); F (F-statistics); Sig. (significance level).
Model Sum of squares DF Mean square F Sig. 1 Regression 85.051 5 17.010 4.635 0.001a Residual 234.901 64 3.670 Total 319.951 69 ↵a Predictors: (constant), tree geometry, crown diameter, SVF, DBH, tree height
- Table S7.
Coefficient table of multiple regression analysis. Std. Error (standard error); t (t-value); sig (significance).
Model Beta Std. Error Beta t sig 1 (Constant) 33.214 2.666 12.458 0.000 Tree height 0.225 0.208 0.361 1.079 0.285 Crown diameter -0.309 0.159 -0.429 -1.944 0.046 SVF 10.872 3.125 0.382 3.479 0.001 DBH -1.368 2.227 -0.105 -0.614 0.541 Tree geometry 2.935 2.957 0.269 0.992 0.325 - Table S8.
Summary of principal component analysis (PCA) analysis. PC (principal component).
PC Eigenvalue Percent (%) variance 1 6.24734 62.473 2 2.58335 25.834 3 0.791836 7.9184 4 0.377464 3.7746
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