Table 7.
Regression equations and coefficients of determination (R2) for regression of principle components scores and traits on seed source climate
| Trait* | R2 | Regression equation† |
|---|---|---|
| PC1 | 0.41 | 17.12 + 0.02 × TD − 0.02 × SHM + 0.47 × EMT |
| PC2 | 0.28 | 3.37 + 0.02 × TD − 0.007 × SHM − 0.02 × FFP |
| PC3 | 0.35 | −2.07 − 0.004 × PAS + 0.004 × CMD |
| DRYWT | 0.51 | 1138.87 − 13.51 × MWMT + 7.24 × TD + 0.05 × MAP − 0.16 × SHM −3.2 × bFFP − 1.91 × FFP − 0.2 × PAS + 7.9 × EMT |
| HEAD | 0.33 | 147.07 − 5.34 × MAT + 2.6 × MCMT + 1.48 × TD + 0.53 × EMT + 0.03 × Eref |
| LFRATIO* | 0.44 | 20.33 + 1.11 × MAT + 0.2 × AHM |
See Table 1 for trait codes and descriptions; PC, principle component.
Climate variables are MAT, mean annual temperature; MWMT, mean warmest month temperature; MCMT, mean coldest month temperature; TD, temperature difference between MWMT and MCMT or continentality; MAP, mean annual precipitation; AHM, annual heat/moisture index (MAT+10)/(MAP/1000); SHM, summer heat/moisture index (MWMT+10)/(MSP/1000); FFP, frost-free period; bFFP, beginning of frost-free period; PAS, precipitation as snow; EMT, extreme minimum temperature over 30 years; Eref, Hargreaves reference evaporation; CMD, Hargreaves climatic moisture deficit.