I would not get so worried about the size of samplings planted. A number of years ago a similar planting exercise took place on Strines Road, although not as large a site as Dan Bank. Within a couple of years the saplings were quite mature and I would be surprised if anyone can now tell the difference. Also it needs to be remembered that planting larger specimens is not only more expensive it is also less successfull in the long term with a high percentage of the larger specimens dying off.
I assume you are comparing the planting which extends along the grass strip between Strines Road/Lower Strines Road. From my recollection which is always a dangerous thing the plant material in size was in keeping with an average landscape scheme; the numbers were certainly more significant than Dan Bank as can be seen from the results on site at present which are in desperate need to be thinned out to allow the better long term specimens to flourish. The point i was trying to make was landscaping is normally the poor relation in a large scale engineering project. As for larger specimens dying off this percentage can be negligible if the species choice is correct, site preparation is professionally carried out, and a maintenance programme is implemented. DM are you carrying out the maintenance or will this be down to SMBC for the next 3-5 years?
Strines 1st, the planting scheme there was undertaken by smbc and the actual numbers were far less than db, regards thinning, yes they are in need of that and its always the practice to over plant at the start of a scheme so the best can be retained for the future and the later being removed to allow this. Dan Bank 2nd, the species that were planted are native and were chosen by the relevant tree officers, yes there will be a percentage that will fail and given the difficulty of covering the steep sections with fresh soil, we have found that areas are a little thin for replanting, this however will be a short term problem, as natural regeneration will take over were we have left off. Regards the maintenance, smbc will be responsible for the care for these trees, which will involve watering and tie adjustment etc, we may be asked to undertake this or it may be dealt with internally.