Battle Skill:

Beastmaster has the melee+1 trait.

I know that this adds to the basic attack of the Beastmaster which would give him 4 basic attacks total.  My question is does this trait add to equipment items such as Staff of Beast?  Now in the walkthrough section of the codex, as well as the video, the Beastmaster used the Staff of Beast on the Warlock for a total of 4 attack.  Shouldn't the Beastmaster be able to add one extra attack with the Staff of Beast or does the Battle Skill only apply to his basic attacks.