Composite Pattern Persistence

Without knowing the details of your data model, I would suspect there is no pattern-based shortcut.  

Most likely you'll have to iterate over the nodes and save the appropriate changes (INSERT, UPDATE, or DELETE). However, having said this, the tree iteration can be done with the Iterator pattern.

Another challenge is when moving nodes within the tree. This may require fairly extensive adjustments of  node records in the database (again depending on your data model)..

Joe Celko wrote a great SQL book discussing tree structures.  Google his name and you'll find it (or search Amazon).