daltontrees

He said 'on my neighbour's side'. Responsibility goes with ownership. Yes the ownership situation should be clarified.

Neighbour's responsibility. Let him know your concerns and keep a record of the communication.

In my experience once Kd is well-established and visible there is very limited scope for only 'monitoring' it. It can but doesn't always progress rapidly, but full aeration takes it from a selective rot mode to full-on loss of strength. So, usually some sort of intervention is recommended. The life of the tree can be increased by crown reduction to avoid basal failure, but as with all reduction you're removing part of the tree's energy source to fight off further decay, accelerating the overall demise. A lean makes management decisions even more difficult, as leaners can in theory fail under the self-weight tension at the base. In practice failure will usually be triggered by a wind event. And there's always the issue that as things get worse the tree gets less climbable and more expensive to remove. 'Monitor' is such a useless recommendation for any risk survey. A specific season and year for reinspection should be specified, and take it from there. As precise a record of current condition and extent of decay and fuiiting is essential for future comparison. Risk is only partly about the tree. Target is as important, either by reference to defensible thresholds set by H&SE or in discussion with the landowner. Rarely I have seen trees with Kd in positions where intervention was not merited. I've spotted Kd on a few and recommended reisnpection after an appropriate period. I've also come a cross a few failures lying on the ground. But I don't have a body of records on what happens from discovery right through to failure.

Experience of the effect of unsympathetic groundworks? Almost daily, unfortunately. There's several issues here. What would be the adverse effects? If carport is just a roof on stilts, minor risk of a direct hit by a screwpile on a root. Deprivation of rainwater for a large section of roots. Proabbaly minor for a tree of that size. Ground water moves sideways to an extent. A solid concrete floor slab would make loss of rainwater much worse because of complete exclusion of water, compaction of soil, leaching of concrete and loss of gas exchange to roots. Firstly ignoring the TPO... If the neighbour is allowed to build a carport on his own land and it adversely affects the tree, it's your problem since your roots are encroaching on his land. Secondly if he builds it and the tree sheds a branch onto it, even if he knows it could happen, again it's your problem. You can't prevent him using his land lawfully as he sees fit just because your tree encroaches on his airspace. Both these could be countered weakly by arguments about reasonableness between neighbours, but in the end your tree has no right to be in his soil or airspace. No amount of time creates such a right. But with a TPO? If no planning permission is required, also no consent for tree works required. The test is therefore whether the works result in wilful damage or wilful destruction of the tree. If not, there is no statutory offence. It all comes down to what is meant by 'wilful'. Not 'careless' or 'reckless' or 'foreseeable'. Just 'wilful'. Does this mean premeditated, deliberate, intended? Grab your favourite dictionary, because the law will not answer this question for you. Personally as a native speaker of english I interpret it as requiring 'intent'. Others seem to want it to mean careless or 'should have taken advice first'. Again personally I feel the law should be changed to ' careless'. This would change the onus of proof in a way thats would reflect the spirit of TPOs. Whether at common law or TPO, I see a presumption in favour of the adjacent owner unless he is being deliberately difficult. He should do the least damaging thing, but proof of intent is mind-reading that even the courts rarely achieve.

My advice is to say nothing more until the OP shows some sort of sign of participating in discussion, or even just acknowledging assistance. He/she has only ever posted twiice on Arbtalk, the last time there were 15 replies but nothing further from the OP. The thread closed with me saying that I personally was not going to contribute unless the OP answered one of the pertinent questions put to him. An utter waste of time, I don't mind helping becasue I have very detailed knowledge of CAVAT, but why bother?

No offence but if you don't know how to do it, don't try. On the other hand, it's just a calculation and not a valuation, so anybody could do one. The key is to know its and your limitations.

Whereabouts in the UK is it?

I dont think this can be right, the biodiversity value is not a relevant consideration in TPOs. It might be in a planning application, but that's a different matter.

That's not hawthorn. Rowan or whitebeam maybe

almost certainly silver birch Betula pendula.

Not good pics. Could be Stereum hirsutum.

They're a mystery. Their main susceptibility is honey fungus. Heterobasidion and Phaeolus have been reported in the USA. I have never seen any other fungal association except very slow degradation of long-exposed wood.

I may be wrong but as far as I know there can't be any liabiity in nuisance or negligence for heave on a neighbour's property. I mean, in theory there could conceptually be liability in very particular circumstances, but I have never heard of it or seen it mentioned as an insurable risk.

Maybe the 3rd one but it's not possible to say for sure. Apple is pretty nondescript still it starts to develop some bark shedding and cracking. Give it a sniff, apple wood is quite distinctive.

Mixture of cherry and plum.