Prosopis tamarugo Phil.: a native tree from the Atacama Desert groundwater table depth thresholds for conservation

Table 1 Behavior of physiological variables of tamarugo toward groundwaterdepletion

Response variables (Y)	Sensitivity	Behavior (slope or ∆)
Predawn water potential	Partially sensitive	−∆
Stomatal resistance	Partially sensitive	+∆
¹⁸O isotope concentrations in foliar tissue	Partially sensitive	+∆
¹³C isotope discrimination in foliar tissue	Insensitive	∆ = 0
NDVI values (activity and defoliation)	Highly sensitive	−∆
Twig growth	Highly sensitive	−∆
GCF	Highly sensitive	−∆

ISSN: 0717-6317