Now, call me soppy, but I really wince when I see plants in pain like this. What's happened is that a little sapling of some pretty little ornamental tree has been planted and then, quite correctly, supported with a stake and a proper tree tie.
Trouble is, nobody came back to visit it. For years, from the looks of the poor thing. It was half the size it should have been, and then there's that awful scar.... Well, I had great pleasure from tearing out that tree tie from the groove it had gouged in the bark, and imagining the sap rising at last (well, next spring anyway) free from such terrible restrictions.
So let this be a lesson to us all: go and check your tree ties! Loosen them gradually if they need it, though trees shouldn't need supporting after the first two or three years so you can take them right off (and remove the stake) after this length of time. Your trees will thank you.