An image from this question (and originally from Karl Niklas' computer model) has prompted the following question:
The branches in this tree divide with increasing frequency as we progress from the bottom of the tree. This clearly makes sense from the perspective of light absorption efficiency and is a phenomenon I have often observed in real trees. The model in question created trees for optimal light favourability, stability and reproductive ability (in this case just light favourability). What other factors affect the length at which a branch splits or produces an offshoot? How does this initial sprouting determine the 'final' shape of the tree's branches.
DISCLAIMER: appreciate that perhaps this question is too broad - my initial interest in the specific subject was from a more mathematical standpoint (I am a physicist). I am simply seeking a more biological/complete explanation to the phenomena.