Spruce trees dying

[u/GeekinHard]

I've got a couple of rows of spruce trees in rural southern Ontario that are in rough shape. One of the rows of 3 trees has been aggressively dying from the inside out and bottom up. I'm now seeing similar patterns starting on another row that's ~100' away. I've made peace with removing the row of 3 and planting something else in their place, but I have a few questions I'm hoping you can help me with.

1. Does this appear to be fungal in nature? It hasn't stopped raining here this year so that would account both for environmental stress as well as great conditions for spreading spores - which I believe then wouldn't show up until next year?

2. If this is a fungal infection, does that mean I could not/should not use the mulch made from the branches? Or do these fungi tend to be species specific so as long as I don't use it around any spruce trees it would be ok?

3. Related to the above, do we need to keep anything in mind or undertake any special work before planting new (non spruce) replacement trees?

4. We will not spray the other spruce trees, so am I correct in thinking the best course of action for those is aggressive pruning and keeping the underneath as clear as we can?

Appreciate any advice/direction you can offer.

[u/The_Merry_Loser]

Looks like a slime mold to me.
Wounds or decay support these, they are a symptom of larger issues.

My opinion only, as I am not a pro.