Such fungi include species which are endophytes and colonise the branches while they are still alive and attached to the tree. Branches in the lower crown are shaded out and die – but remain attached to the tree - and that is when decay becomes active. The fauna is dependent on these aerial dead branches and, while they may persist if the branch fails and falls, they appear not to actively colonise fallen branches per se.
A few species are said to develop in dead branches high in the canopy.
A few species appear to be associated with branches which have recently snapped and are still partially attached to the tree, hanging from the crown. It is unclear at present whether such species will colonise freshly fallen branches.