This is a new forest feature called "Savanna".
I just deleted the tiny bushes and their shadows from the alpha-canal in the tree dds-file.
So there are some disadvantages:
-) There is a shadow fault in the jungle file, where in some cases, there is a shadow without a tree.
-) The model will be full calculated, but the objects will be transparent.
This feature can be used as anew terrain feature.
The download file includes the art files, button and xml files.
-) If you use special map scripts, where forests are hard coded, then you have to add this feature too
I did this model for my ancient Mod Pie's Ancient Europe. Enjoy!