Some landings at Dumby have been patio-d very nicely by some folks. Areas which have been worked are the landing under Mugsy, and the slope under Slap Happy. Another area is under 2HB, although I don't know why this area was chosen as the landing was not greatly improved and erosion was not as much a problem as in other places (I have no problem with that patio being there, however). Since I've not been too regular recently I don't know when these were put in.
The worse area of erosion is under Slap happy. This is due to a combination of the popularity of the problems, and their lines being difficult to cover with one pad. Since the area is rather dank, regeneration of turf is not likely without stopping of climbing on those problems. Instead it would be perhaps best to protect the turf that is there by fully patio-ing the whole area (up to the turf), built up from the tree to the sucker boulder. This amounts to a lot of work.
I visited some boulders in Boulder, Co, last year, and saw that they could do with some patio-ing. However, the local I was with told me that was unethical, and it should be left "natural", despite years of erosion had now exposed large, pointy boulders. I got the impression he agreed with me, but the local consensus was against maintenance.
At Dumbarton, I suspect no one would be against patio-ing the landings to protect further erosion. But what about else where in Scotland? I've patio-d landings in remote-ish places, where erosion is not a problem, but just to make the things safer. I've done this by rearranging the nearby stones to fill in holes or trundled large boulders. I think this was reasonable as my attempts tried to make things look natural, with (hopefully) no large areas of exposed earth.
Removal of plants and trees is a step further. At Dumbarton, there was a large tree growing out from under the Eagle boulder which has been "pruned" (read: chainsawed) on a few occasions, and a small tree below 2HB has been removed. Anything goes at Dumbarton. Elsewhere though, removal of trees has happened and, although I've not done it personally, I've enjoyed climbs which have been opened up. I'm not too sure what the legality of pruning wild plants and trees is - I think picking wild flowers is against the law, so I imaging cutting down trees is probably frowned upon. If there is a law, it's 99% irrelevant as no one is policing the remote anarchy of scottish bouldering. It comes down to a judgement of the person involved - is the route worth the tree? To calculate this, I propose the following formula:
Worth of route = Number of stars + number of people likely to try to climb it per year
Worth of tree = Floor[(Estimated age of tree^2)/10] + 1 (if native) + 1 (if visually appealing) - inf (if rhododendron)
