I have a 100 year old monkey puzzle tree approximately 35ft- 40ft high. I am worried that it's branches are turning brown quite rapidly from the trunk out. The branch tips appear green with new growth and there are cones forming. Also of concern there is a lot of sap coming from the full length of the trunk. I was concerned a couple of years ago whilst clearing the ground under the canopy of brambles to plant a few blackcurrant bushes together with a strawberry bed and onions, when I noticed sap at the bottom of the trunk, investigation at the time suggested that this was normal. The ground under the tree now is again overgrown with brambles, thistle, bindweed, mares tail. About 6 years ago the plot next to it was dug out for foundations for a new building. The advice/instruction that was given (and strictly adhered to) was not to dig the ground under the, to not cut any root greater than 2 inches in diameter and to fence the area beneath the canopy. The concrete foundations were poured but the building has not been built. The area around the remains fenced off. Any advice or help with what may be able to be done to save the tree would be greatly appreciated. There is a TPO listed for the tree and it is recognised as a local landmark. I know there will be a lot of disappointed and upset people if it has to be removed. I am in north-west of England 20 miles from Scottish border.