What are the strategies of root competition in the forest?

[False Prophet]

I learned that trees and plants compete for survival just like other species. They compete for sunlight and nutrients in the soil. If you're a tree who wants to catch some rays, the goal is to grow as big and tall as possible, and make the enemy trees eat shade. But how do they compete for nutrients in the earth? Do the roots try to tangle each other, strangle each other, play paper-rock-scissors or what? Do roots have territorial conflicts, or do they not actually meet? I'm wondering what goes on in the forest underground.

 

[Another God]

Knowing virtually nothing about plant root dynamics, this is just a guess, but it makes a lot of sense to me, so I'll go with it until told otherwise.

It seems to me that the competition would simply be as straight forward as space and nutrient supplies. If there are roots everywhere, then the new roots growing outward have to move around the existing roots. I doubt that this would be a real problem though, there would be much more soil space than any competing roots would take up. So the next aspect would be nutrient supply, but actually, thinking on this more, nutrient poor soils is actually a problem, not a normal state phenomenon. To suppose that there is a limited supply of nutrients being competed for seems a bit extreme.

Perhaps there is competition to be closest to the top of the soil though, to catch the new nutrients as they enter the soil from decomposing matter?

 

[Phobos]

Also knowing nothing about root dynamics, I'll say this based on other competition mechanisms in nature...
(1) competition for space
(2) competition for nutrient uptake (e.g., most efficient)
(3) competition nutrient usage (e.g., ability to use more diverse or more limited nutrients)

I'd be interested to hear about any root-ish warfare. Chemical releases? Co-opting parasites?