Precise distribution of trees using particles for architecture

What is the best way to add trees in an architectural visualization project with Blender? Well, there are several different ways to add trees to a project like using a polygon model of a tree and even textures applied to a plane. But, after you get the tree on the 3D View of Blender you will face another problem, which is the distribution of those trees.

By using particles we can distribute those trees quite well, and for those of you that never had the opportunity to use particles to distribute trees, there is a really nice tutorial about precise distribution of trees using particles posted at BlenderMama.

precise distribution trees particles architecture with Blender