Sex-specific, age-dependent sensitivity of tree-ring growth to climate in the dioecious tree Juniperus thurifera

New Phytol. 2009;182(3):687-697. doi: 10.1111/j.1469-8137.2009.02770.x. Epub 2009 Feb 9.

Abstract

Tree features may modulate the sensitivity of radial growth to climate, leading to a nonuniform response. Age-related increases in climatic sensitivity have been observed repeatedly. Sex-related climatic sensitivity is also possible because of the long-term differential reproductive cost between the sexes. This study analysed the simultaneous effects of age and sex on the sensitivity of tree-ring growth to climate. Ring widths were measured from 50 female and 50 male Juniperus thurifera trees, 50-350 yr old, growing under a Mediterranean continental climate. Response functions were calculated based on tree-ring chronologies and monthly climatic records. Climatic sensitivity decreased with increasing age. Young trees (50-100 yr) were the most climatically sensitive to June-July precipitation, which affected growth positively. We found a significant interaction between age and sex in the climatic response of J. thurifera, with young females the most sensitive to summer water stress. Our results suggest that age-dependent climatic sensitivity can be determined by site-specific limiting environmental conditions and species-specific architectural and physiological adjustments during ontogeny. This study supports that the different ontogenetic stages of J. thurifera differ in their root structural traits and that sex-related sensitivity to summer drought may be attributable to less efficient water use by females.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Climate*
  • Juniperus / growth & development*
  • Rain
  • Regression Analysis
  • Seasons
  • Spain
  • Temperature
  • Time Factors
  • Trees / growth & development*