Preparing yamadori Pinus Sylvestris for collecting.

I found really nice pine tree growing on a top of a bedrock in a small amount of organic matter.
Most of the roots seem to grow in this and can be digged out but there is also one big root growing down in to a crevice in a bedrock.
I'm thinking that I could do ground layer on it.
My question is what else there is to do to help the tree to survive from the transplantation proses?
If I put some organic fertiliser next to the trunk will it grow feeder roots in it?

- Gorilla

My guess: the tap root may have predominantly only water supply /anchoring function. If there is enough feeder roots in the "bed" then the chances of collection are quite high.

Ground layer: never seen a successful project on scott pine.
Fertilising: organic ferts may act as an invitation to the meal for a number of animals. I have experienced problems with wild boars in the woodlands and rodents in the garden/fields.
Watering the "bed" now and then can promote the growth of feeder roots there ( if feasible ). But it may take a season or two.

The process of transplantation is well described all around. The more challenging ( in my opinion ) is the postransplantation care: how much water, how much sun and when... For that one need some experinece.

Just a note:
Scotts are quite difficult trees to collect and provide aftercare. As a freshman I have lost some very nice ones. I am sure that I could have make it better now, but no chance to get the clock back.

Thank you Vlad!
I just read that they can be ground layered from the root, but not from the trunk.
It has some roots in the top soil to , but like you said I think the fat tap root is very important for this tree as it is almost as thick as the trunk is.
Maybe adding some good soil and watering at dry periods would be the best way prepare this tree for collecting.
If I cut the tap root half way trough would it encourage the tree grow more roots close to the trunk?
I could dig up some other pines to practise with and wait a year or two before trying to get this one of the ground.

Rather than partially cutting the tap root I would wrap a fairly heavy aluminum tightly around it.. That would slowly reduce its ability to supply the tree and force the finer roots to take on more of the task.

Thank you Marty Weiser.
What about doing both?
Would it be quicker as the live vein thickens faster than the whole root?

Roots need few basic things to develop and survive. Water is one of the basic. You know the biotop so you should be able to judge if there is enough water available in summer for the feeder roots in the bed to develop. No water - you cannot expect too much new growth. Any reduction of the tap root without water supply of the roots in the bed ( natural/artificial ) could weaken the whole tree and reduce the likeliness of successful collection.

I think it will completely dry out several times in summer time.
I could arrange some sort of bucket to collect rain water and slowly drips it to the right place.
Would pine bark mixed up with sphagnum moss make good substrate for roots to grow?

Vlad in 2015 Herbert A made a post about
air layering Pinus Mugo. He also said that pinus sylvestris can be ground layered from the major roots.
Now I don't know Herbert A in person but I have seen some of his work in the web and he seems to know what he's doing with pines.
If I add some new media for the roots to grow and use a wire to slowly choke the root and provide sufficient amount of moisture I should be able to collect the tree in two years. As this is the time that it has left before the city swallows it.

Old saying: A single swallow does not make spring. But I do respect Herbert.

Watering:
I have used a material called hydrogel for horticulture. It keeps moisture. But again here it may attract some animals. To keep them away I sometimes use a kind of fence made from local material.

Anyway, I am sure you will find your way. Good luck.

Luck is what I need in this case.
I just heard that the construction work is going to start in January 2021.
So there's no time to properly prepare the tree.

Just some picks of the pine I was talking about.
I think it's worth a try to save it.

Collect as many roots as you can. Put it in a custom box with good drainage that conforms to the root shape - this can be a larger box with partitions around the roots - there will be air on the other side of the roots. The standard planting media is pumice from 1 - 9 mm size since it is free draining to allow oxygen flow, but holds moisture. The other media that is is used very coarse sawdust by Randy Knight, but on the ground over weed block cloth. I suggest you keep it from freezing after collection and perhaps use some bottom heat under the roots - watch for drying of the planting media. Since they are planning to do major construction, I would not be too concerned about how much damage you do to the rock arrangement when you pry it apart to get to the roots. Some nice thick steel bars (25 mm or so) and come-alongs might be useful. Be careful about putting too much tension into a nylon or similar rope since they can stretch and do nasty things if something breaks under load. Good luck.

Thank you Marty Weiser for your reply and advices.