Does taking Greater Spirit Totem remove the +CHA component of the spirit's slam, effectively dealing less damage if you have a high charisma? Or should I read it as 1d6+CHA?
Additional question: When do the spirits from the lesser spirit totem attack? Beginning of the turn? End of the turn? Whenever I want? (for example when passing by an enemy?)
Greater Spirit Totem: While raging, the spirits that surround the barbarian become dangerous to any enemy adjacent to the barbarian. Living enemies adjacent to the barbarian at the start of her turn take 1d8 points of negative energy damage. In addition, the spirit wisps can now attack foes that are up to 15 feet away from the barbarian and the slam attack deals 1d6 points of negative energy damage. 
Lesser Spirit Totem:
While raging, the barbarian is surrounded by spirit wisps that harass her foes. These spirits make one slam attack each round against a living foe that is adjacent to the barbarian. This slam attack is made using the barbarian’s full base attack bonus, plus the barbarian’s Charisma modifier. The slam deals 1d4 points of negative energy damage, plus the barbarian’s Charisma modifier.