Is this tree salvageable?

[AKT-Dog]

Hello all. I'm glad I found this site, it's pretty cool.

I live in Alaska, and winter is coming... so I decided to address this tree-situation to professionals, who may be able to help me save my dad's tree before the chance of recovery begins falling with the temperature.

The Tree
Honestly I'm not even sure what type of tree this is, but my grandfather gave it to my dad about 20-ish years ago, and it has led a rugged life. It has been attacked by countless moose, has allowed a disgustingly high variety of creatures to climb all over it (loose morals), and at several low points in life - it has in turn - assaulted vehicles.

Anyways this is dad and grandpa's tree, and I'd like to save it if possible.

We had a few weeks of high winds over the summer, and the southern-most section of the 4-way fork (at ground level) was blown over. It lay that way for about a week, then we got some ratchet straps and supported it back in it's approximate original position. That happened 3 months ago, and it doesn't seem to be doing well at this point. The leaves on that section turned yellow and fell off way before the other 3 sections, which seems definitive.

What more can I do to save this section? There is a big gap at the base where it tore free - should I fill that gap to prevent various infection? Will it help to saturate the root system with some supplement? Is there a more efficient way to secure all the fork sections together so they support each other?

Attaching pictures for diagnostic purposes. the split at the base appears to be about 8-9 inches wide and maybe 4-5 inches deep (to soil).
split
width
depth1
depth2 (with snail)

These pics show the differences between the fallen section and the others:
northwest
northwest close up
west

This picture here is how we have secured the sections to one another. I would like to find smaller straps for each section, connected to a center bull-ring with adjustable fasteners. Does a system like this already exist commercially?

Thanks in advance for any and all advice.

AKT-Dog
https://drive.google.com/open?id=1310IUOJKYT4uNoOeLLkHhSFb4VaFyR0o

 

[ATH]

Not seeing the pics... (click on "upload a file" at bottom of post to post pics in message).

But based on what you wrote, here are some things to consider:
It is unlikely that a portion that split off as badly as that sounds can be reattached...especially if not attempted immediately. Especially this late in the year - a better chance in early spring when the new tissue is being formed...obviously not something you had control over, just saying that there is a better chance of it working if it had happened then.

Wrapping something around the tree is not the way to do that. You can use those to temporarily hold it up while you work on it, but putting bracing (threaded rod) through the tree down low and cabling up high will be better. A strap around will girdle the tree.

Don't fill cavities with anything.

Extra water is good if the soil is dry. Don't saturate it, but keep good moisture. NO high nitrogen fertilizer going into winter. This could stimulate new growth that won't harden off in time.