J Plant Ecol ›› 2020, Vol. 13 ›› Issue (3): 331-340.DOI: 10.1093/jpe/rtaa019

• Research Articles • Previous Articles     Next Articles

Drought effects on the plasticity in vessel traits of two endemic Magnolia species in the tropical montane cloud forests of eastern Mexico

Ernesto Chanes Rodríguez-Ramírez1 , José Antonio Vázquez-García2,† , Ignacio García-González3,† , Othón Alcántara-Ayala1 and Isolda Luna-Vega1, *   

  1. 1Laboratorio de Biogeografía y Sistemática, Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico, 2 Laboratorio de Ecosistemática, Instituto de Botánica, Departamento de Botánica y Zoología, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Jalisco, Mexico, 3 Departamento de Botánica, Escola Politécnica Superior de Enxeñaría, Universidad de Santiago de Compostela, Lugo, Spain

    *Corresponding author. E-mail: luna.isolda@gmail.co; isolda_luna-vega@ciencias.unam.mx
  • Received:2020-01-06 Revised:2020-04-14 Accepted:2020-05-05 Online:2020-05-09 Published:2020-06-01

Abstract:

Aims

We aimed to evaluate how climatic fluctuations influence the plasticity of anatomical vessel traits and the width of annual tree-rings of two relict-endemic Mexican Magnolia species. Notwithstanding, few studies have assessed the drought effect on vessel traits in tropical montane cloud trees of eastern Mexico.

Methods

Through digital images of growth rings, we assessed the tree radial growth rate, age of the trees and plasticity in vessel traits regarding climatic fluctuations of the Mexican Magnoliaspecies studied. We compared vessel density, hydraulic diameter and percentage of conductive area in drought years (DY) and non-drought years (NDY) in two Mexican Magnolia species.

Important Findings

For the first time, the plasticity that occurs in porous wood vessel traits to long-term climatic fluctuations was analysed for two endangered Magnolia species (Magnolia vovidesii and M. schiedeana) from two tropical montane cloud forests in Mexico. We found that temperature and precipitation were strongly associated with differences in tree-ring width when DY and NDY were compared. Our analyses revealed that a high plasticity in vessel anatomy of diffuse-porous wood was related to temperature and/or water availability for both Magnolia species studied. We concluded that anatomical adaptations to DY resulted in a substantial reduction in vessel traits when compared with NDY, and that the plastic adaptations played an essential role in water transport and safety for the survival of the studied species during stressful long periods.

Key words: adaptability, climate variability, drought–growth relationship, Magnolia schiedeana, Magnolia vovidesii, quantitative wood anatomy

摘要:
本文旨在探讨气候变化如何影响两种特有墨西哥木兰的导管性状可塑性和其每年的年轮宽度。尽管如此,很少有研究评估干旱对墨西哥东部热带山地云林导管性状的影响。通过生长年轮的数字图像,我们对所研究的墨西哥木兰树种的径向生长率、树龄和导管性状可塑性进行了评估,比较了两种墨西哥木兰树种在干旱年和非干旱年的导管密度、水力直径和传导面积百分比。本研究首次对墨西哥两个热带山地云林中的两个濒危木兰树种(Magnolia vovidesiiM. schiedeana)的多孔木质部导管性状对长期气候变化的可塑性进行了分析。结果发现,当比较干旱和非干旱年份时,温度和降水量与年轮宽度的差异密切相关。扩散型多孔木质导管解剖结构具有很高的可塑性,这与所研究的两种木兰树种的温度和/或水的有效性有关。我们的结论是,与非干旱年份相比,对干旱年份的解剖学适应导致了导管性状的大量减少;这些可塑的适应性在植物长期环境胁迫下的水分运输以及生存的安全性方面起着重要的作用。

关键词: 适应性, 气候变化, 干旱与生长关系, 木兰属植物, 定量木材解剖