Hibernate transaction boundaries

I'm using Hibernate (in a Grails application) and transactional boundaries are service methods, that is, every time a service method is called a transaction, and every time a service call completes, the transaction is either rolled back or aborted.

If one of the database operations causes a database trigger to run, and that trigger makes changes to persistent data, will the changes be rolled back or committed when the service call ends, or will the changes be made that were triggered by the "outside" transaction trigger?

Thanks Don