Another reason why I'm happy to have a truck...

We have a pin oak in the front yard that's having some issues with its lower branches not being very healthy. I had to do a bunch of trimming to hopefully convince her to devote more resources to the branches that are doing well.

I'm also happy that I have a truck with a full eight-foot bed that'll handle all of the cut-offs from this.

Does anyone know what might be causing this anyway?