Symbol	Dimension	Description
$\mathit{\alpha }$	−	Fraction of the asymptotic conductance reached by root length $l^{\ast }$
${\mathit{\alpha }}_{lat}$	$L^3{P}^{-1}{T}^{-1}$	Fraction of the asymptotic conductance reached with $n_{lat}$
$\mathit{\chi }$	−	Eq. (22)
${\mathit{\chi }}_{lat}$	$L^3{P}^{-1}{T}^{-1}$	Eq. (25)
$d_{inter}$	L	Inter-branching distance
$H_{collar}$	P	Collar water potential
$H_{s,eq}$	P	Equivalent soil water potential
$H_{soil}$	P	Soil water potential
$H_{sr}$	P	Soil–root water potential
$H_x$	P	Xylem water potential
i	−	Root zone number
$J_r$	$L^3{T}^{-1}$	Radial volumetric flow rate
$J_x$	$L^3{T}^{-1}$	Axial volumetric flow rate
$\mathit{\kappa }$	$L^3{P}^{-1}{T}^{-1}$	Asymptotic root conductance
${\mathit{\kappa }}_{+}$	$L^3{P}^{-1}{T}^{-1}$	Eq. (21)
${\mathit{\kappa }}_{-}$	$L^3{P}^{-1}{T}^{-1}$	Eq. (21)
${\mathit{\kappa }}_{+,lat}$	$L^3{P}^{-1}{T}^{-1}$	Eq. (23)
${\mathit{\kappa }}_{-,lat}$	$L^3{P}^{-1}{T}^{-1}$	Eq. (23)
$K_{comp}$	$L^3{P}^{-1}{T}^{-1}$	Compensatory water uptake conductance
$K_{rs}$	$L^3{P}^{-1}{T}^{-1}$	Global conductance of the root system
$K_{rs,n_{lat}}$	$L^3{P}^{-1}{T}^{-1}$	Root system conductance after addition of $n_{lat}$ laterals
$k_r$	$L{P}^{-1}{T}^{-1}$	Root radial conductivity
$k_x$	$L^4{P}^{-1}{T}^{-1}$	Root axial conductivity
$K_r$	$L^3{P}^{-1}{T}^{-1}$	Segment radial conductance
$K_x$	$L^3{P}^{-1}{T}^{-1}$	Segment axial conductance
$l^{\ast }$	L	Root length for a specific for a faction $\mathit{\alpha }$ of the asymptotic conductance
$l_{root}$	L	Root length
$l_{seg}$	L	Segment length
$N_{inter}$	−	Number of root segments between two successive branches
n	−	Root segment number
$n_{lat}$	−	Number of laterals
$q_r$	$L{T}^{-1}$	Root radial flux
r	L	Root radius
SUD	$L^{-1}$	Standard uptake density
SUF	−	Standard uptake fraction
$\mathit{\tau }$	$T^{-1}$	Root intrinsic property
$T_{act}$	$L^3{T}^{-1}$	Actual transpiration of the root system
z	L	Distance to root tip