Regression equations and r2 values for red oak and red maple to determine the force required to break a codominant stem with one of two rod placement locations or nonrodded controls. Diameter (dia) was measured 30 cm (12 in.) below the crotch; it ranged from 4.9 to 15.6 cm (1.94 to 6.15 in.)
| Species | N | Rod placement | Equation to determine force in lb | r2 |
|---|---|---|---|---|
| Red maple | 10 | at-crotch | 447 (dia) – 526 | 0.64 |
| 8 | above | 859 (dia) – 1,722 | 0.89 | |
| 11 | control | 546 (dia) – 1,051 | 0.79 | |
| Red oak | 9 | at-crotch | 820 (dia) – 2,024 | 0.89 |
| 15 | above | 1,541 (dia)– 3,975 | 0.72 | |
| 10 | control | 603 (dia) – 1,337 | 0.94 |