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.
fweibull(P, SX, PX, X = 50)
P | Water potential (positive-valued MPa) |
---|---|
SX | Shape parameter |
PX | Water potential at X loss of conductivity. |
X | If 50, PX is the P50. |
Ogle, K., Barber, J.J., Willson, C., Thompson, B., 2009. Hierarchical statistical modeling of xylem vulnerability to cavitation. New Phytologist 182, 541-554.
curve(fweibull(x, SX=30, PX=2), from=0, to=5)