Table 2. Summary of community and ecosystem properties in green roof modules planted with no plants, monocultures or one, three or five life-form groups.
| Planted treatment | n | Planted species richness | Realized species richness | Canopy diversity (H′) | Aboveground Biomass index | Aboveground biomass variability | Surface temperature (°C) | Water capture (kg) | Water loss (kg) | Multi-functionality index | Proportion Radiation reflected |
| no plants | 9 | 0 | na | na | na | na | 26.59±0.39 | 0.86±0.03 | 0.92±0.02 | −0.63±0.52 | 0.16±0.0016 |
| Campanula rotundifolia (tall forb) | 3 | 1 | 1.0±0.00 | 0.00±0.00 | 73.94±3.29 | 0.37±0.063 | 25.86±0.19 | 0.80±0.02 | 0.86±0.04 | −1.09±0.19 | 0.18±0.0029 |
| Danthonia spicata (grass) | 3 | 1 | 1.0±0.00 | 0.00±0.00 | 94.06±10.31 | 0.31±0.012 | 24.56±0.40 | 0.73±0.01 | 0.78±0.01 | −1.57±0.34 | 0.18±0.0022 |
| Deschampsia flexuosa (grass) | 3 | 1 | 1.0±0.00 | 0.00±0.00 | 169.17±24.75 1 | 0.25±0.030 | 23.82±0.87 | 0.68±0.03 | 0.74±0.05 | −1.97±0.36 | 0.18±0.0036 |
| Empetrum nigrum (creeping shrub) | 3 | 1 | 1.0±0.00 | 0.00±0.00 | 46.11±8.42 | 0.30±0.045 | 25.92±0.51 | 0.79±0.05 | 0.84±0.09 | −1.44±0.87 | 0.17±0.0015 |
| Gaultheria procumbens (creeping shrub) | 3 | 1 | 1.0±0.00 | 0.00±0.00 | 9.28±2.19 | 0.51±0.030 | 26.07±1.00 | 0.76±0.02 | 0.83±0.05 | −1.95±0.75 | 0.16±0.0007 |
| Poa compressa (grass) | 3 | 1 | 1.0±0.00 | 0.00±0.00 | 118.72±25.28 | 0.48±0.132 | 23.50±0.35 | 0.81±0.01 | 0.86±0.05 | 0.42±0.12 | 0.19±0.0062 |
| Plantago maritima (tall forb) | 3 | 1 | 1.0±0.00 | 0.00±0.00 | 52.39±6.79 | 0.39±0.024 | 25.48±0.26 | 0.82±0.01 | 0.89±0.02 | −0.66±0.35 | 0.17±0.0033 |
| Sedum acre (succulent) | 3 | 1 | 1.0±0.00 | 0.00±0.00 | 75.56±15.55 | 0.25±0.042 | 23.36±0.58 | 0.73±0.04 | 0.77±0.08 | −0.87±0.90 | 0.18±0.0036 |
| Solidago bicolor (tall forb) | 3 | 1 | 1.0±0.00 | 0.00±0.00 | 74.22±3.65 | 0.21±0.027 | 21.77±0.49 | 0.82±0.02 | 0.94±0.04 | 1.45±0.08 | 0.21±0.0027 |
| Sagina procumbens (creeping forb) | 3 | 1 | 1.0±0.00 | 0.00±0.00 | 93.17±27.86 | 0.30±0.038 | 24.93±0.54 | 0.83±0.03 | 0.93±0.06 | −0.17±0.67 | 0.18±0.0071 |
| Rhodiola rosea (succulent) | 3 | 1 | 1.0±0.00 | 0.00±0.00 | 8.72±2.56 | 0.55±0.234 | 25.47±0.49 | 0.70±0.00 | 0.77±0.02 | −2.51±0.28 | 0.16±0.0015 |
| Sedum spurium (succulent) | 2 | 1 | 1.0±0.00 | 0.00±0.00 | 29.75±10.08 | 0.55±0.063 | 25.37±1.17 | 0.78±0.03 | 0.87±0.02 | −1.24±0.26 | 0.18±0.0074 |
| Vaccinium vitis-idaea (creeping shrub) | 3 | 1 | 1.0±0.00 | 0.00±0.00 | 0.33±0.33 | na | 26.84±0.50 | 0.77±0.01 | 0.84±0.04 | −2.16±0.18 | 0.16±0.0005 |
| Creeping shrubs | 5 | 3 | 3.0±0.00 | 0.33±0.13 | 18.30±1.27 | 0.40±0.061 | 26.05±0.29 | 0.80±0.02 | 0.87±0.02 | −1.31±0.23 | 0.16±0.0007 |
| Creeping forbs | 5 | 3 | 1.0±0.00 | 0.00±0.00 | 44.27±9.75 | 0.33±0.064 | 26.17±0.39 | 0.76±0.00 | 0.84±0.03 | −1.95±0.22 | 0.17±0.0028 |
| Grasses | 5 | 3 | 3.0±0.00 | 0.55±0.11 | 112.90±11.09 | 0.35±0.053 | 23.68±0.49 | 0.90±0.05 | 0.88±0.04 | 1.67±0.64 | 0.19±0.0041 |
| Succulents | 5 | 3 | 2.6±0.24 | 0.41±0.11 | 57.47±3.50 | 0.19±0.026 | 23.45±0.70 | 0.76±0.04 | 0.80±0.05 | −0.42±0.42 | 0.18±0.0040 |
| Tall forbs | 5 | 3 | 3.0±0.00 | 0.50±0.12 | 63.27±5.98 | 0.32±0.040 | 22.71±0.81 | 0.82±0.03 | 0.94±0.04 | 0.97±0.74 | 0.20±0.0040 |
| Creeping shrubs, creeping forbs, succulents | 5 | 9 | 6.0±0.45 | 0.97±0.07 | 58.03±3.12 | 0.22±0.016 | 23.56±0.38 | 0.81±0.03 | 0.85±0.04 | 0.34±0.44 | 0.18±0.0023 |
| Creeping shrubs, creeping forbs, tall forbs | 5 | 9 | 6.2±0.20 | 0.80±0.18 | 65.60±4.61 | 0.37±0.045 | 23.29±0.37 | 0.85±0.01 | 0.90±0.06 | 1.03±0.35 | 0.19±0.0045 |
| Creeping shrubs, grasses, creeping forbs | 5 | 9 | 5.0±0.32 | 0.49±0.15 | 120.33±8.72 | 0.42±0.073 | 23.55±0.33 | 0.83±0.02 | 0.93±0.03 | 0.67±0.40 | 0.19±0.0030 |
| Creeping shrubs, grasses, succulents | 5 | 9 | 6.8±0.37 | 1.15±0.11 | 120.57±8.80 | 0.26±0.031 | 23.52±0.46 | 0.79±0.02 | 0.90±0.02 | −0.02±0.41 | 0.20±0.0025 |
| Creeping shrubs, grasses, tall forbs | 5 | 9 | 7.4±0.60 | 1.11±0.10 | 107.97±13.05 | 0.31±0.038 | 22.77±0.86 | 0.80±0.01 | 0.95±0.04 | 0.63±0.54 | 0.20±0.0037 |
| Creeping shrubs, tall forbs, succulents | 5 | 9 | 6.8±0.58 | 1.12±0.08 | 73.67±4.58 | 0.25±0.045 | 22.09±0.30 | 0.82±0.03 | 0.96±0.05 | 1.40±0.47 | 0.20±0.0037 |
| Creeping forbs, tall forbs, succulents | 5 | 9 | 6.0±0.45 | 1.31±0.08 | 57.53±4.54 | 0.21±0.022 | 22.80±0.62 | 0.80±0.01 | 0.89±0.02 | 0.60±0.41 | 0.19±0.0031 |
| Grasses, creeping forbs, succulents | 5 | 9 | 5.8±0.37 | 1.24±0.06 | 106.00±8.51 | 0.34±0.042 | 23.12±0.20 | 0.81±0.03 | 0.86±0.03 | 0.56±0.44 | 0.19±0.0034 |
| Grasses, creeping forbs, tall forbs | 5 | 9 | 5.2±0.49 | 1.20±0.10 | 100.67±2.90 | 0.31±0.058 | 23.16±0.28 | 0.80±0.02 | 0.93±0.04 | 0.40±0.42 | 0.20±0.0030 |
| Grasses, tall forbs, succulents | 5 | 9 | 5.8±0.37 | 1.30±0.09 | 108.30±10.04 | 0.23±0.047 | 22.71±0.34 | 0.83±0.01 | 1.01±0.04 | 1.20±0.18 | 0.20±0.0023 |
| Grasses, creeping forbs, tall forbs, succulents, creeping shrubs | 20 | 15 | 8.7±0.37 | 1.37±0.04 | 101.14±3.14 | 0.25±0.019 | 22.99±0.27 | 0.82±0.01 | 0.93±0.02 | 0.84±0.25 | 0.19±0.0019 |
1
The best ten treatments for each performance measure are in bold (for aboveground biomass variability and surface temperature, optimal functioning is indicated by the lowest values).