"If we did nothing to help the forest, the bush and the birds there will be nothing to protect in 10 years," Mr Amner said.
The iwi considered all possible control options, and balanced the calculated risk with very strict monitoring.
Pest eradication by ground teams was one option, but would be costly and need a lot of people.
"We simply don't have the man-power based in the Ruapehu area to undertake this mahi (work) right now."
One of the eight conditions set by the Ruapehu tribe is that deer repellent is added to poison baits dropped in the Karioi Forest area, to keep deer populations available to hunters.
Another is excluding some areas from any drop.
Poison baits are prohibited from dropping over water sources used for drinking, but the iwi has asked for even larger exclusions from dropping over water.
It will do its own monitoring of water, birds, plants and animals after each drop. Agreement with the next drop will depend on what is found.
The iwi has always been consulted about 1080 poison operations in its area, but this consultation was on a different level, Mr Amner said.
"Everybody involved has had really good input. That's new - everyone working together for a common outcome. That sets the pathway forward."
