Thanks for the feedback. I intended this model to look as it does, because as some have already stated sparsely populated trees do exist in real life. I created this one in an older version of Arbaro. I reloaded it this morning and found a setting I think may increase the branches, but so far when I export the obj is empty.

Attached is an image of another tree I created. I can't remember which program I did this one in. The only problem - the mesh is 65 Mb. I loaded it into Poser this morning, setup the material zones and exported and the mesh went to 120 Mb. I'm going to look around and see if I can find a program or python script that will reduce a mesh file size.