This is a somewhat hypothetical question, but:
This little Quercus robur seedling was pulled out during a weeding session. Apparently it’s at least two years old and the original tip was cut off at some point, causing it to develop a double tip/stem.
Admittedly, we have dozens, if not hundreds of healthy and vigorous (and single-tipped) seedlings in the neighborhood (we had a huge mast year), but minor 2 is at an age where she will try to protect every life form at hand, so the debate is whether we will replant the seedling instead of putting it on the compost heap.
Which leads to the question at hand:
What will be the long-term effect if such a seedling grows into a mature tree?
I assume it will develop a double trunk. Will there be stability problems? Greater risk of fungal infection or breakage? Other side effects or potential problems?
(Let’s exclude the myriads of reasons that the seedling won’t make it and assume generally favorable conditions and success (even if human-aided) in outcompeting others.)