Remember:
A reversed tree happen when the distance between top and ground (or structure you are on) is nearly equal to tree size.
In atcs you can do a reversed tree on bunker by building two bamboos or two bamboos and a brick on the highest part of the bunker.
![Image](http://img291.imageshack.us/img291/669/shot0949.jpg)
you can see that two bamboos and a brick is the max size if you want to build a tree on them.
![Image](http://img62.imageshack.us/img62/8348/shot0948.jpg)
Once you build these structures you can build the tree like this:
![Image](http://img20.imageshack.us/img20/2253/shot0953.jpg)
or this:
![Image](http://img705.imageshack.us/img705/9045/shot0950.jpg)
Then, wallwalk under the tree you just built and select a tree again.
you can see it indicates green as the picture under.
![Image](http://img839.imageshack.us/img839/9682/shot0952.jpg)
Now you only need to click with mouse to build it
![Very Happy :D](./images/smilies/icon_biggrin.gif)