Table 1.

Algorithms of the MST metrics used in the present study

Symbol	Concept	Explanation	Formula
L	Leaves	The number of nodes with a single link
N	Nodes	The number of nodes
dg	Degree	The number of links for a given node
m	Links	The number of links	N – 1
LF	Leaf fraction	Fraction of leaf nodes (L) in the MST	LF = L/N
D	Diameter	The longest link between two nodes of an MST	D = dlogest/m
K	Kappa	Measure of the broadness of the degree distribution	K = <dg.^2>/<dg>
TH	Tree hierarchy	Quantifies the trade-off between large scale integration in the MST and the overload of central nodes	TH = L/(2 mBCmax)

Note: D is normalized by the number of links. BC_max is the highest betweenness centrality of any node in the tree. Betweenness centrality is the fraction of all paths on the tree that include (but do not end at) that node.