Table 3.
Significance of the minimum adequate models to explain the relationship of root respiration (log transformed) as a function of root age (days log transformed), root N concentration (root N, N%) and their interaction. Relative importance of parameters, where total equals 1, was determined using the R package ‘relaimpo’. ***Significant at P < 0.001.
| Dataset | n | R2 | Relative importance of terms in model |
Minimum adequate model | |
|---|---|---|---|---|---|
| Field experiment | 163 | 0.43*** | Log root age (x1) Root N (x2) |
0.57 0.43 |
y = 1.736 − 0.258x1 + 0.522x2 |
| Greenhouse experiment | 161 | 0.46*** | Log root age (x1) | 1.00 | y = 3.138 − 0.427x1 |
| Field and greenhouse experiment combined | 324 | 0.43*** | Log root age (x1) Root N (x2) |
0.85 0.15 |
y = 2.546 − 0.362x1 + 0.185x2 |