Dr. Tom Masselter

Doktorarbeit:

Structural and functional aspects of
secondary growth in Palaeozoic plants:
quantitative analysis and simulation.

Tom Masselter 1, Nick Rowe 2 & Thomas Speck 1
1 Botanischer Garten, Institut für Biologie II, Universität Freiburg, Germany
2 Botany and Plant Architecture Bioinformatics, Montpellier II, France

The aim of this work is to understand functional aspects of different constructional strategies of extinct woody plants. Some Palaeozoic plants lack significant development of secondary outer tissue such as bark that allows an increase in stem diameter. As a consequence, secondary growth of internal tissues such as phloem and especially xylem may lead to mechanical destruction of parenchymatous inner cortex without its replacement by secondary cortical tissues. Fossil plants studied, include stems from a Palaeozoic seed fern (Lyginopteris oldhamia) that were measured in order to analyse changes of different tissues due to secondary growth during ontogeny. The results will be used as a basis for simulating the growth of these plants with both physical models and computer models (FEM & CAD). The investigations will help to understand developmental constraints influencing the appearance of tree-like growth forms in the Devonian radiations and help us to understand why the lignophyte/seed plant "bauplan" has been so successful and may also shed light on the intriguing question why other constructional strategies have become extinct.