Table 1.

List of variables

Name	Symbol	Units	Description
Root axial conductance	K x	cm4 hPa−1 d−1	Root segment capacity to transport water axially
Root radial conductivity	k r	cm hPa−1 d−1	Root segment capacity to transport water radially
Root system total hydraulic conductance	K rs	m3 MPa−1 s−1
Root system total hydraulic conductivity	k rs	m MPa−1 s−1	K rs normalized by the total root surface area
Water uptake density	WUD	cm3 d−1 cm−3	The volumetric flow of uptake per soil voxel volume
Water depletion	WD	cm3 cm−3	The water content change over successive observation times
Volumetric soil water content	θ	cm3 cm−3
Soil water potential	h	MPa
Soil bulk density	ρ b	g cm−3
Tracer concentration	[Gd-DTPA2−]	mmol L−1
Tracer accumulation	Acc.	mmol L−1	The increase of Gd-DTPA2− concentration over the considered period
Solute longitudinal dispersivity	α L	cm
Solute lateral dispersivity	α T	cm