Is traffic subsequent to a SASL/GSSAPI bind encrypted?

Is traffic subsequent to a SASL/GSSAPI bind encrypted?

When making a SASL/GSSAPI bind to an LDAP server over port 389 (ldap:///), after the authentication is finished is the resulting LDAP traffic encrypted? If so, is there a document or RFC that describes this?

Assume that no STARTLS command is issued by the client.

Note that the question "Is it secure to be using LDAP, or is LDAPS the only secure option?" mentions some ways to secure an LDAP connection but does not address the question of whether or not connecting via SASL/GSSAPI encrypts subsequent data communications.