Estimated soil volume (m3) required by green ash trees grown on three sites in Lincoln, Nebraska
| Method of estimation | Site | ||
|---|---|---|---|
| Campus | Large planter | Small planter | |
| Perry (12, 13) based on stem caliper | 5.2 | 4.6 | 4.1 |
| Lindsey and Bassuk (8) based on crown projection, soil and climatic factorsa | 6.7 | 5.2 | 5.5 |
| Bakker (2) based on crown projection | 16.3 | 13.3 | 13.9 |
| Actual soil volumeb | 22.4c | 5.1 | 1.8 |
↵a To use the method of Lindsey and Bassuk, we assumed leaf area index (LAI)=4, available water holding capacity = 22%, and rainfall frequency = 14 days. Mean water loss for trees on each site was estimated from leaf area and transpiration rate assuming a mean transpiration rate of 1.5 mmol m-2s-1, based on measurements from this study.
↵b Soil volume calculated from area of planters assuming a 1 m rooting depth.
↵c Soil volume of campus trees estimated as crown projection × 1 m rooting depth.