The project will take place in Montpellier at UMR AMAP, an interdisciplinary research unit dedicated to advancing fundamental knowledge about plants and vegetation ().
The doctoral student will be integrated into the research groups “ Biodiversity” and “Plant Architecture and Functioning” within the unit's 2027–2032 research project.
They will be affiliated with the GAIA doctoral school at the University of Montpellier ().
Material Resources:The Ph.D. student will have a dedicated workstation in a shared office.
A new laptop and accessories (headset, external hard drive) will be provided at the start of the thesis.
The doctoral student will have direct access to the fossil material in the University of Montpellier's paleobotany collections, which contain numerous anatomically preserved woody stems from the Devonian, Carboniferous, and Permian periods, as well as more than 2,000 prepared thin sections, wafers, or peels of these specimens.
The doctoral student will also have access to the UMR's paleobotany and microscopy facilities for the preparation and observation of specimens.
This material will be supplemented by specimens from other collections, notably in Paris for Mesozoic and Cenozoic woods, and potentially by field collection work.
The Ph.D. student will receive regular guidance, with a formal meeting with their thesis advisor at least every 15 days.
General Project Context:Today, wood is found in many plants, and woody species play a key role in ecosystems.
Despite the relative abundance of fossil wood, there is little data on the functional properties of this tissue over geological time, and fundamental questions about plant evolution and the dynamics of past ecosystems remain unanswered.
The ANR PALWOOD project (2026–2030) aims to fill this gap by combining, for the first time, analyses of plant paleodiversity and paleophysiology.
The project focuses on the Paleozoic era, from the emergence of wood in the early Devonian (410 Ma) to the major crisis affecting plants at the end of the Permian (250 Ma).
PALWOOD brings together participants from three UMRs: AMAP (Montpellier), CR2P (Paris), and EEP (Lille), as well as international collaborators.
PhD project: Within the PALWOOD project, this PhD project will focus on the evolution of anatomical disparity in homoxylous wood (= wood without vessels).
The main part of the PhD project will aim to quantify and analyze this anatomical disparity to test two major hypotheses: (1) that anatomical disparity of wood increased rapidly shortly after the appearance of this tissue;
(2) that unique combinations of characters existed in the Paleozoic that no longer exist today (“alternative designs”).
The doctoral student will identify the quantitative and qualitative characters relevant to creating a database of the anatomical features of homoxylous woods, populate this database based on observations of thin sections of as many types of Paleozoic, Mesozoic, and Cenozoic woods as possible, and will analyze anatomical diversity, particularly by taxonomic groups and by geological period.
A more exploratory component of the PhD project will address the functional implications of anatomical diversity, with a focus on hydraulic properties.
The objective will be to reconstruct and compare the hydraulic conductivity of wood from several types of Paleozoic plant stems to test (1) whether there was already a diversity of hydraulic “strategies” in the Paleozoic and (2) whether the range of hydraulic conductivity values for wood was similar to that of today.
The doctoral student will perform measurements on thin sections and synchrotron images (some of which have already been acquired, while others will be obtained during the project), apply an existing model developed at AMAP (Tanrattana et al.
2019) to several taxa (notably from the Devonian), and, if time permits, contribute to the further development of this model.
Qualifications:The candidate must hold a master's degree in a field such as Organismal Biology, Evolutionary Biology, or Ecology and Evolution, with, in all cases, a strong background in paleobotany and/or botany and plant histology, as well as a good command of written and spoken English.
A background in paleontology is a plus but not required and can be acquired during the course of the dissertation.
The candidate must have demonstrated, strong teamwork skills, as well as high integrity and scientific rigor during their previous research experiences.
To apply: Submit the following on this CNRS job portal: (1) a detailed resume (1–2 pages) listing the titles, locations, and supervisors of any internships completed, as well as your Master's 1 and 2 (or equivalent) grades;
(2) a cover letter (1–2 pages) that must include a description of your experience in (paleo)botany and your motivation for pursuing a Ph.D. Written applications will be evaluated by the two thesis advisors (A.
Boura and A-L Decombeix).
Candidates selected at this stage will be invited to an online interview in December before a selection committee composed of the three ANR project leaders (A.
Boura, A-L Decombeix, B.
Cascales-Minana) and two researchers external to the project.