I know in the case of Clachan an Diridh the site was tree-free when it was built, but is now in a clearing in a wood. It may be that the area around sites was kept clear of trees when they were still in use

Cheers
Andy

The idea of a monument surrounded by woodland with avenues cut through the trees would undoubtably increase the visual (and perhaps the accoustic) impact the monument could have on it's visitors and heighten the theatricallity of any rituals perfomed.
The selective removal of trees could be used to create avenues of approach and control access to a monument. The same method could also be used to emphasise or restrict certain viewpoints.

Greetings bawn79,

From what I've read, the forests, in the vicinity of settlements, and therefore monuments, was gradually being cleared during the Neolithic, and by the Bronze Age vast tracts of land were open.

If that is the case, then sightlines would be free of trees at the monuments, as distant forests wouldn't impede on long distsance views.

What is meant by "alignments"? Is it landscape, monument, or astronomoical? Some landscape features could be hidden by nearby trees, whereas visible sightlines to nearby barrows on ridges or hills might not be. The same could be said of astronomical sightlines. Perhaps, as has been suggested on this forum post, avenues of sight were created by clearing trees (not something I'd considered before, but an interesting theory).

Certain important sights, such as Stonehenge and Avebury, have been proved to be relatively tree-free during their construction.

It would be intersesting to have a map of the forests of Neolithic and Bronze Age Britain magicked into our clammy hands. I, for one, could spend many a happy hour by the fire with one.

Regards,
TE.