The Weibull function, as re-parameterized by Ogle et al. (2009), which describes the relative conductivity as a function of the plant water potential. The relative conductivity (relK) is scaled to be 1 when water potential is zero. The slope of relK versus P at the inflection point can be calculated from the shape parameter (SX) as slope = -SX/100.
Usage
fweibull(P, SX, PX, X = 50)
Arguments
P
Water potential (positive-valued MPa)
SX
Shape parameter
PX
Water potential at X loss of conductivity.
X
If 50, PX is the P50.
References
Ogle, K., Barber, J.J., Willson, C., Thompson, B., 2009. Hierarchical statistical modeling of xylem vulnerability to cavitation. New Phytologist 182, 541-554.