I've been making a giant Cherry Blossom tree build and noticed leaves seem to constantly despawn at a slow rate.

I've know from past experience that in some tree types like Jungle and Oak, if you destroy one of the top logs, the leaves will start to despawn.

However, in this build the cherry blossom leaves seem to despawn differently.  All the leaves in the canopy were 'grown' by planting trees on dirt blocks.  The only thing I did for some of them was to cut a few of the lower logs so I could make the trunks look like branches.  However, I never cut any of the logs on the top half of the tree.