1) This field is tagged as a woodland however it is more of a shrubland, with tall grass and sparse, low trees (according to historical imagery it used to be an agracultural field but it looks as if it is bieng restored back into a forest) the closest OSM gets to shrubland is "heath" but I am not sure if this is fitting.
2) I have never heard the name "Jubilee Wood" the people at amersham school call it "farmers field" 
3) I am new to OSM and is it OK to change someone elses feature without their permission?
Thanks in advance :)