What can I do bout this?? Fungus in spirea roots!

Pretty simple, would like to know if any one out there might be able to help correct this issue? Would some fungicide work, or do I need to remove what ever is dead in the interior? Thanks in advanced, Jacob.

Those are unlikely to be doing any damage to your tree. They MAY be an indication that your soil is a bit too wet though.

Thank you Jim for calming my nerves on the subject, thaught I might have been keeping too moist before I noticed this.