Descriptions	Symbols	Units
The Qilian mountains	QLMs
Heihe River Basin	HRB
Qinghai spruce	QHS
Evapotranspiration	ET	mm
Transpiration	T	mm
Evaporation	Es	mm
Canopy interception	Ei	mm
Net radiation	Rn	W m−2
Shortwave radiation	Rs	W m−2
Photosynthetic active radiation	PAR	W m−2
Air temperature	Ta	°C
Soil temperature	Ts	°C
Vapor pressure deficit	VPD	kPa
Atmospheric precipitation	Pa	mm
Throughfall	Pt	mm
Atmospheric relative humidity	RH	%
Soil water content	SWC	%
Wind speed	u	m s−1
Stem flow	S	mm
Diameter at breast height	DBH	mm
Sapwood area	As	cm2
Boosted regression trees	BRTs