Here is my displacement map. 
Displacement by Verinince, on Flickr
Here is my model. 
Before by Verinince, on Flickr
Here is after the displacement maps are applied. 
After by Verinince, on Flickr
What’s causing this and how do I fix it?
So how do I fix it?
You just have your high-poly models to re-assign a UVW (I suggest that you can compare the use ZBrush Plugins UV Master), or you can directly make a tree model that matches the low side, and then use a similar texture 3DMAX reflection, the high poly models with the past … (This English translation from the machine, bad English, please forgive me)
You have me very confused. Are you suggesting I use UV Master to UV Map it before I generate a displacement map?
In fact, your question is obviously the UVW, so you just put down your Before low-level model first, and then assign a good UVW, then produced within the Zbrush displacement map, otherwise the map will be produced as shown as overlapping, simply means that uvw distribution was not good enough cause problems.Want to help you
How do I assign a good UVW?
Use ZBrush Plugins UV Master (This is perhaps the most convenient for your question.)
I am using it, though it doesn’t seem to help very much because my model is one sided and I don’t know where to draw the seam.
Hi Victel,
you can create a automatic map in the UV map section of the tool palette.