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Tree growth and architecture - Levels of organizations

Architecture analysis :
a tool for tree life history knowledge

Icone Image



Tree growth and architecture

Icone Image

Growth and branching processes

Two elementary processes lead to tree development : growth and branching.
Growth process originates in apical bud where is located the apical meristem tissue. At this place cells division and elongation take place to generate new elements of the leafy axis (node, internode, leaf, axillary bud) that expand when buds break. So the growth process includes organ formation (organogenesis) and organs expansion (extension phase).

Meristem is a set of embryonic cells situated at the apical part of each axis. These particular cells are always able to divide and thus to generate new cells which can then differentiate in specialized cells constituting tissue (pith, epidermal tissue, vascular bundles...) or foliar organs. The division activity of meristematic cells also generate small set of embryonic cells: the axillary meristems from where originate (are issued) lateral shoots

Branching process allows a plant to explore many directions, from an axis through new lateral axes. It includes lateral buds initiation and their development (Caraglio & Barthélémy 1997 Reference).

Tree growth and architecture - Levels of organizations