When you apply copyright for 2nd edition of your book do you need to track and list all changes you made to the first edition, when you apply for copyright?
You don't need to apply for copyright. You write it, you have the copyright. Or you write it as an employee for your company, your company owns the copyright. You can then apply to register the copyright. Just as for the 1st edition, you have to give the copyright office a copy of the complete work, so they know what exactly is copyrighted. They don't care about how much difference there is to the first edition. And they will not even try to take the 1st edition and a list of changes and re-create the 2nd edition.
Two other answers have already said as much, but perhaps it bears a simpler restatement:
No. When you register copyright for a second edition, you must deposit a complete copy of the second edition with the copyright office. You do not need to list the changes.
Anyone who wants a detailed list of the changes can compare the two copies to create the list. The copyright office does not need a list of the changes and will neither make one nor ask for one.
In case you have given party Q permission to copy edition 1 but not edition 2, you might want to sue Q for copyright infringement of the second edition. To succeed in that suit, you would have to prove that they copied edition 2 rather than edition 1. You prove this in court. Since the works are both available for inspection, there's no need to "track changes", you simply point to the specific improperly-copied text. The only involvement with copyright registration is that in the US, you have to register the work before suing for infringement.