Good structure already :) The light source looks more like it's at ground level, like a car light or something. This is largely because of the two bottom branches at the right side which are shaded from below. If you're going for spookiness you should probably change the palette from lively brown to something else. Is the tree dead? Is the scene at night with moonlight beaming down. Is it a foggy swamp? A grey, desaturated green, desaturated blue etc might be more fitting.

Edited by ErekT - 25 January 2015 at 7:45am

When adding texture, be careful not to lose your forms to it. The bottom area of the trunk had nice, clear bolume before, but now it's all a mix of shadows and looks flat. As a general rule, the shadows produced by texture should be milder than those produced by large-scale detail such as the form of the object.