By default, Mycorrhiza Wiki has no protection nor authorization, thus anyone who has access to your wiki can edit. You may want to turn on authorization.
Groups
Every user is part of a group. The groups are anon, editor, trusted, moderator, admin. They have different rights. Anonymous users can only read hyphae, editors can edit hyphae, trusted editors can also rename them, moderators can delete them, and administrators can do everything.