try this:
instead of texture=entSkin1; try: texture=mtlSkin1;

At the top of your script have something like:
bmap branches = <branchtexture.tga>; //whatever your texture is called

And replace: texture[0]=<entSkin1>; with texture[0]=<mtlSkin1>

make sure you have the "branchtexture.tga" in your work folder (whatever the braches texture on you branches is).
Under where you call your material in script:
material wind_branches
{
skin1 = branches;
etc......
}

This in not tested, and I am no expert, but worth a try.