Hello,

Yes, you can remove the girdling roots with a sharp chisel and mallet, as long as the roots have not fused to the trunk. Read more about girdling roots here: https://extension.umd.edu/resource/girdling-roots

And here: https://hort.ifas.ufl.edu/woody/remove-circling.shtml

As you can see in the pictures in the articles, the mulch around your tree seems to be adequate and it is not against the trunk.

However, roots are not the only thing that girdle trees. Wires and ropes around the trunk can cause girdling as the tree increases in girth. They will cut off the flow of nutrients and water moving through the tree and nourishing it. I recommend that you remove the string of holiday lights from the trunk.

Thank you for contacting Ask Extension.