Aura of Decay

[Kazumetsa Raijin]

I'm a little confused by the wording on Aura of Decay.

1. How many rounds does it last once activated?

2. Do I have to activate it once every round?

3. Can I activate it an amount per day equal to my "cleric"(druid in this case" level, and; does it last one round, does it last an amount of rounds equal to my "cleric"(druid) level, or does it stay on until I turn it off?

Decay Subdomain
Associated Domain: Plant.

[/b]Replacement Power: The following granted power replaces the bramble armor power of the Plant domain.

[b]Aura of Decay (Su): At 8th level, you can emit a 30-foot aura of decay as a standard action. Living creatures in this aura (except you) take 1d6 points of damage per round as their flesh rots. They also take a cumulative –1 penalty to Strength each round they remain in the aura. Once outside the aura, the penalty fades at the rate of –1 per round, but it begins building again if they reenter the aura. Plant creatures take 2d6 points of damage per round. You can use this ability for a number of rounds per day equal to your cleric level. These rounds do not need to be consecutive.

[Brf]

As I understand it, the Aura abilities remain in effect until they are deactivated, or until their per-day time runs out.

[Kazumetsa Raijin]

So, if I were level 8 in this case, I could activate it as a standard action up to 8 times per day maximum, and the aura would last an overall time of 8 rounds per day maximum.

Am I understanding the perspective?