Search

Because climate can affect xylem cell anatomy, series of intra-annual cell anatomical features have the potential to retrospectively supply seasonal climatic information. In this study, we explored the ability to extract information about water stress conditions from tracheid features of the Mediterranean conifer Juniperus thurifera L. Tracheidograms of four climatic years from two drought-sensitive sites in Spain were compared to evaluate whether it is possible to link intra-annual cell size patterns to seasonal climatic conditions. Results indicated site-specific anatomical adjustment such as smaller and thicker tracheids at the dryer site but also showed a strong climatic imprint on the intra-annual pattern of tracheid size. Site differences in cell size reflected expected structural adjustments against cavitation failures. Differences between intra-annual patterns, however, indicated a response to seasonal changes in water availability whereby cells formed under drought conditions were smaller and thicker, and vice versa. This relationship was more manifest and stable at the dryer site. Etant donne que le climat peut influencer l'anatomie des cellules du xyleme, il est possible que des sequences des caracteristiques anatomiques intraannuelles des cellules puissent, retrospectivement, fournir des informations climatiques saisonnieres. Dans cette etude, nous avons explore la capacite d'extraire de l'information au sujet des conditions de stress hydrique a partir des caracteristiques des tracheides du Juniperus thurifera L., un conifere de la region mediterraneenne. Les tracheidogrammes de quatre annees climatiques provenant de deux stations sujettes a la secheresse en Espagne ont ete compares pour evaluer s'il est possible de relier le patron intra-annuel de la dimension des cellules et les conditions climati-ques saisonnieres. Les resultats ont montre qu'il y avait une adaptation anatomique specifique a la station, telle que des tracheides plus petites et plus epaisses dans la station la plus seche, mais qu'il y avait aussi une forte empreinte climatique dans le patron intraannuel de la dimension des tracheides. Les differences entre les stations quant a la dimension des cellules refletaient les adaptations structurales previsibles pour prevenir les accidents dus a la cavitation. Cependant, les differences entre les patrons intraannuels etaient dues a une reaction aux changements saisonniers dans la disponibilite en eau, a la suite de laquelle les cellules formees dans des conditions de secheresse etaient plus petites et plus epaisses et viceversa. Cette relation etait plus evidente et stable dans la station la plus seche. [Traduit par la Redaction], Introduction The wood anatomical structure of woody plants is mainly genetically determined and can therefore be used as a trait for taxonomic classification. However, intraspecific variability is also subject to [...]

Copyright of Annals of Forest Science (EDP Sciences) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)