The "split" seems to have healed over. Was it a split or a injury to the bark/cambium that healed over? As long as that heals/seals and does not allow rot into the wood it should be O.K.
The other "splits" are normal for maples as they age and grow in diameter.
The inner bark/phloem is living tissue and transports nutrients from the leaves to the roots. The cells in this layer die and is replaced by a new layer of cells by the vascular cambium. These dead cells are pushed out and become the outer bark. As the tree grows this outer bark may split as the diameter of a tree increases. Twigs and small branches remain smooth.
On the inside of the cambium, it also generates the xylem, living cells which transport nutrients and water from the roots to the tree crown. This is also known as sapwood. Yearly growth rings in a trees wood are layers of xylem, which eventually die and become known as heartwood.
Unless you have splits or dead areas in the cambium/phloem what you are seeing is normal. The only spot I'd check is the 2nd picture where there is some loose dead bark at the base.
My red maple split the trunk when it was young. The split has closed. It’s 6 years old now. I had it planted when it was very little. The canopy and trunk have grown a lot. But the bark on the trunk keeps splitting. It’s almost like huge bark won’t grow with the tree. I was hoping someone could tell me why and if there is anything I can do. Also if it will continue to thrive or if this is a bad sign of things to come.
