Hi woodnicer,
This is quite easy to do if you have the right software. I would be happy to help you if you would like me to.
The best method would be to purchase a digital OS basemap from a supplier such as Promap (or similar). You can then map the trees with a hand held GPS (these cost about £100), or plot them by eye on the map. There is lots of software that could do this but I use Pear Technology PT Mapper Pro. A cheaper alternative to buying the OS basemap would be to mark out the site boundary in Google Earth, export it as a KML file, and then map the trees in PT Mapper Pro.
Then, if you have measured the girths of the trees and would like these indicated on the plans I would export it to AutoCAD and then map the trees with ArborCAD. This would automatically illustrate the girths of the trees. Also, of you measure crown spreads you can also plot these on the map. The finished maps can look quite good.
If you were to buy all of the software it would be pretty expensive. But its not much work. If you plotted the trees I could produce the maps that you are hoping for in a couple of hours. You are welcome to contact me if you wanted to do that.
Ben
