Table 1.

The definition, abbreviation, and unit for 16 functional traits in this study.

	Trait	Abbreviation	Definition	unit
Aboveground trait	Leaf area	LA	Leaf surface area	cm2
	Leaf area ratio	LAR	The ratio of total leaf area to biomass of an individual	cm2 g-1
	Leaf carbon content	LC	Leaf carbon content per mass	%
	Leaf dry matter content	LDMC	The ratio of leaf dry mass to leaf fresh mass	g g-1
	Leaf nitrogen content	LN	Leaf nitrogen content per mass	mg g-1
	Leaf phosphorus content	LP	Leaf phosphorus content per mass	mg g-1
	Specific leaf area	SLA	Dividing leaf area by dried mass	cm2 g-1
	Specific stem length	SSL	The ratio of stem length to stem dry weight	cm g-1
	Leaf thickness	T	Leaf thickness at the widest part of each leaf	cm
Root trait	Fine-root diameter	DIAM	Average fine root diameter	mm
	Root branching intensity	RBI	Number of root tips per fine-root length	tips cm-1
	Root nitrogen content	RN	Root nitrogen content per mass	mg g-1
	Root phosphorus content	RP	Root phosphorus content per mass	mg g-1
	Root tissue density	RTD	The ratio of root dry mass to its volume	g cm-3
	Specific root area	SRA	The root surface area per dry mass	cm2 g-1
	Specific root length	SRL	The root length divided by its dry mass	cm g-1