Variation in traits related to water transport in Nothofagus dombeyi helps to explain its latitudinal distribution limit in the Chilean Andes

Background: Functional traits related to water transport in plants, their variations and correlations can be related to the latitudinal range limits of tree species.Aims: We evaluated whether the variation and covariation of traits related to safety and efficiency in water transport in Nothofagus dombeyi could help to explain its climatic and geographic limits along the Chilean Andes.Methods: We quantified and correlated the intraspecific variations of leaf mass per area, wood density (WD) and leaf and xylem hydraulic conductivities in three populations of N. dombeyi near its northern and southern range limits and in its mid-latitudinal distribution.Results: N. dombeyi showed a considerable intraspecific variation in traits related to safety and efficiency of water transport. These traits showed functional restrictions both in the northern and southern distribution limits, where climatic conditions could be considered stressful. We found a negative covariation between safety and efficiency traits (e.g. WD vs. leaf specific hydraulic conductivity) in the southern population, while hydraulic conductivity traits (xylem and leaf conductivities) showed a positive covariation along the three populations.Conclusions: Functional traits allow inferring the potential specific filter mechanisms underlying the current range limits of N. dombeyi along the climatic-gradient, where their individuals exhibit variations in strategies for acquiring water resources associated with embolism resistance.