Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → États-Unis → 2017 → Drought Responses in Loblolly Pine (Pinus taeda L.) as Inferred from Analyses of Range-wide Tree Ring Isotopic Composition

North Carolina State University (2017)

Drought Responses in Loblolly Pine (Pinus taeda L.) as Inferred from Analyses of Range-wide Tree Ring Isotopic Composition

Lin, Wen

Titre : Drought Responses in Loblolly Pine (Pinus taeda L.) as Inferred from Analyses of Range-wide Tree Ring Isotopic Composition

Auteur : Lin, Wen

Université de soutenance : North Carolina State University

Grade : Doctor of Philosophy (PhD) 2017

Résumé partiel
Loblolly pine (Pinus taeda L.) is the most important timber species in the USA. Due to the large planted area and high productivity, it plays a crucial role in carbon uptake and economic vitality of the southeastern United States. Climate projections for the southeastern USA indicate that the frequency and intensity of drought will increase, in part due to higher temperature and more intense precipitation events separated by increased length of dry periods. The physiology and productivity of loblolly pine may be negatively affected by those future climate predictions. The major objective of this study was to understand how loblolly pine responds to drought and fertilization over its distribution range using tree ring cellulose stable isotopic compositions, plus an associated objective of modifying a high throughput α-cellulose extraction method so that it applies to conifer wood. Cellulose extraction has been the rate-limiting step in stable isotope studies of plant materials. The Multiple Sample Isolation System for Solids developed by Wieloch et al. [Dendrochronologia, 29, (2011)] was a major advance in the tree ring α-cellulose extraction methods, offering greater throughput and reduced labor input compared to traditional alternatives for separate wood samples. However, the utility of the method for resinous conifer species may be limited by the need to remove extractives in a separate pretreatment step. We successfully complemented this method with a pretreatment step and designed a special apparatus so that it can be applied to conifer wood, while minimizing the need of additional labor.

Présentation

Version intégrale (3,80 Mb)

Page publiée le 10 octobre 2018