head-first wrote:
It's a really interesting idea. I notice that the barrows on 'Five Barrows Down' near Cherhill aren't wooded, despite being in an arable field. On the other hand, East Kennet is well and truly covered (I think it's in arable land?).
Obviously, you need to look back and see if the field was out of use for a period of say 10 years so the trees could establish.
In Ireland many monuments have gained their trees in just the last 20* years since EU subsidies made it attractive to stop farming patches of land thus removing livestock to control growth. The obvious fields to stop farming first are the ones with the tombs etc in them.
*A lot of barrows and mounds have had scotts pines on them for a hundred years or more as part of Victorian landscaping. Also, due to the need for free fuel caused by the famine, there aren't many trees in Ireland over 160 years old.