| Model | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| α | 2466.4 | −23987.7 | −16689.2 | −12588.1 | 345.2 | 32693.3 | 24,846 | 47,222 |
| m3/ha | 451 | 318 | 309 | 309 | 311 | 300 | 235 | 312.99 |
| p-value | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 |
| Ave. yield | 7764 | 7466 | 7429 | 5946 | 2226 | 3236 | ||
| p-value | 0.000 | 0.000 | 0.000 | 0.000 | 0.072 | 0.016 | ||
| prod. area | −100 | −120 | −129 | −126 | −119 | −131.09 | ||
| p-value | 0.002 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | ||
| Reg III | −10,117 | −14,989 | −25,900 | −24,518 | −29,733 | |||
| p-value | 0.001 | 0.000 | 0.000 | 0.000 | 0.000 | |||
| Reg IV | −13,745 | −30,367 | −30,348 | −37,147 | ||||
| p-value | 0.000 | 0.000 | 0.000 | 0.000 | ||||
| Reg V | −27,545 | −27,799 | −35,130 | |||||
| p-value | 0.000 | 0.000 | 0.000 | |||||
| % >40 year | 17,394 | |||||||
| p-value | 0.054 | |||||||
| R2 (adj) | 35.68 | 47.57 | 48.88 | 50.28 | 51.92 | 54.38 | 54.74 | 54.1 |