American elm maintenance schedule, cost outlay, and compounded costs (in U.S. dollars) for the existing tree maintenance program
| Year appliedz | Treatment | Projected cost outlayy | Compounded cost (at 7% per year) |
|---|---|---|---|
| 0 | Minor prune | $250 | $430x |
| 1 | Soil injection | $100 | $161 |
| 3 | Soil injection | $100 | $140 |
| 5 | Soil injection and minor prune | $350 | $429 |
| 7 | Soil injection | $100 | $107 |
| Total | $900 | $1,267 |
↵z Year 0 represents the first year of the maintenance program; year 7 is the last year. The tree would be replaced, using this time scale, at the beginning of year 8. Costs are assumed to occur at the beginning of the year, and benefits at the end of the year.
↵y These projections should consider the rising costs of maintenance (inflation) over time in making the estimates. In other words, the figures should be a estimate of the cost outlay at that time in the future. Further, the possible increase in tree removal cost attributable to retaining the tree has not been considered here. If there are increased removal costs, from removing a larger and/or less sound tree, this additional cost should be included here as a cost to the retention program.
Otherwise, the removal cost is considered as part of the establishment cost of the replacement tree.
↵x For example, the calculation is 250(1.07)8 =$430.