is there a way to move something from one .blend to another?
I have a tree in the default Lsystem .blend and a landscape in another can i put the two together and how
thank you for any help
Just hit Shift F1 with your landscape blend open, navigate to the Lsystem blend and go down the list to Object, click on that then pick the mesh in there and open.
you have to append the different objects into your final scene: SHIFT+F1, browse through the blend file as it was a directory, find the objects directory and from there, append the requested object(s).
For more on the topic:
http://download.blender.org/documentation/oldsite/oldsite.blender3d.org/142_Blender tutorial Append.html
hope this helps,