Table 1.

A list of commonly used abbreviations (see Supporting Information Table S1 for a list of all RSIP parameters).

Abbreviation	Explanation
Plant size
D R	Maximum rooting depth of plant (m)
L R	Maximum lateral root spread, one‐sided (radius) linear distance from stem reached by roots (m)
W R	Rooting spread or diameter (m)
H S	Height of plant shoot (m)
W S	Width of plant shoot (m)
V S	Canopy volume, calculated using an ellipsoidal shape:
	$V_{\mathrm{S}}({\mathrm{m}}^3)=\mathrm{\pi }\times H_{\mathrm{S}}\times W_{\mathrm{S}}^2/6$
DBH	Stem diameter (diameter at breast height) of trees (cm)
Plant shape
Y : X shoot	Aboveground dimensional aspect ratio (Y : X shoot  = H S/W S)
Y : X root	Belowground dimensional aspect ratio (Y : X root = D R/W R)
S : Ry	Vertical shoot : root ratio (S : Ry = H S/D R)
S : Rx	Horizontal shoot : root ratio (S : Rx = W S/W R)
Climate
MAP	Mean annual precipitation (m)
MAE	Mean annual potential evapotranspiration (m)
A i	Aridity index (A i  = MAP/MAE)
S a	Seasonality index or annual water storage index: S a = min[P sur, P def]
Datasets
RSIP	Root Systems of Individual Plants
RPGE	Root Profiles for Global Ecosystems (Schenk & Jackson, 2003)