Cladoptosis
Cladoptosis is the regular shedding of branches. It is the counterpart for branches of the familiar process of regular leaf shedding by deciduous trees. As in leaf shedding, an abscission layer forms, and the branch is shed cleanly.
Functions of cladoptosis
Cladoptosis is thought to have four possible functions: self-pruning, drought response liana defence, and in some plant families, normal leaf drop is by shedding small whole shoots, rather than individual leaves.- Self-pruning is the shedding of branches that are shaded or diseased, which are potentially a drain on the resources of the tree.
- Drought response is similar to the leaf-fall response of drought-deciduous trees; however, leafy shoots are shed in place of leaves.
- In tropical forests, infestation of tree canopies by woody climbers or lianas can be a serious problem. Cladoptosis, by giving a clean bole with no support for climbing plants, may be an adaptation against lianas, as in the case of Castilla.
- In the conifer family Cupressaceae, most species shed old foliage by cladoptosis, rather than individual leaf drop. Dawn redwood and western redcedar provide examples; within the family, the only species that do not use cladoptosis for shedding old foliage are the junipers in sections Juniperus sect. Caryocedrus and J. sect. Juniperus.