Can functional hydraulic traits help to explain the current distributional limits in two Nothofagus species with contrasting leaf habit?

  • Fernando Carrasco-Urra universidad de concepcion
  • Alfredo Saldaña
  • Marco Molina-Montenegro Centro de Ecología Molecular y Funcional, Instituto de Ciencias Biológicas, Universidad de Talca, avda. Lircay s/n, Talca, Chile. 3 Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile.
Keywords: embolism, leaf habit, functional trait, hydraulic trait, marginal population


The Chilean Andes is a latitudinal climatic-geographical gradient with a marked variation of the environmental conditions, and on its slopes, several Nothofagus species are distributed, which differ both in their leaf habit and in the extension of their ranges and limits of latitudinal distribution. It has been proposed that the hydraulic traits such as specific leaf conductivity (KL) and xylem-specific hydraulic (KS) are indicators that allow us to understand the mechanisms that underlie the ecology of vascular plants, due to their high sensitivity to variations in environmental conditions at intra as interspecific levels. Moreover, at leaf habits level, the plant ecologists have found differences in the composition and foliar construction as also in the transport and use water resource between evergreen and deciduous, nevertheless, when environmental or climatic conditions are unfavorable, both leaf habits tend to converge in their hydraulic responses. This study evaluated if the responses of these functional traits, by sampling in marginal populations in the northern and southern limits are highly significant for latitudinal limits of distribution in the evergreen N. dombeyi and deciduous N. pumilio compared with their populations of central distribution. We hypothesize that both species will have a functional convergence of hydraulic traits in their distribution limits (KL and KS), with low values, because these traits are highly sensitive to unfavorable climatic conditions. Our results showed that KL and KS had lowest mean values in northern and southern comp