Table 1.

Reduced regression equations and predicted relative drought avoidance of desert willow, fruitless mulberry, and yellow bells at -10 and -100 MPa atmospheric water potential

SpeciesIrrigation levelRegression equationszDrought avoidanceV
-10MPa-100 MPa
Desert willowLowY =-63.8 +81.7 X abc18± 16100± 12
ModerateY =-52.5 + 76.0 X abc23± 1699± 12
HighY =-76.0 + 87.3X abc11 ± 1699± 12
Fruitless mulberryLowY=-82.5± 100.3 c18± 12118 ± 12
ModerateY =-78.8 ± 95.6 X c17± 12112 ± 12
HighY=-67.7±86.8X be19± 13106± 12
Yellow bellsLowY =-69.0 + 89.9X abc13+1795± 13
ModerateY =-47.4 ± 65.7X ab18± 1784± 13
HighY =-38.3 ± 58.6X a20± 1779± 14
  • z Y = drought avoidance, X = LOG(-atmospheric water potential). Regression equations followed by the same letter are not significantly different at p=.O5 as determined by multiple linear regression with indicator variables for species and irrigation level

  • y Predicted drought avoidance ± 95% confidence interval at -10 and -100 MPa atmospheric water potential.