Waikato Regional Council says pest eradication programmes it shares with the Department of Conservation could be under threat because of planned cutbacks.
DoC has announced it's cutting 140 jobs and merging 11 conservancies into six.
The council's national heritage programme manager, Kevin Collins, says the collaboration means the two organisations divvy up the workload and share costs.
He's concerned about DoC's ability to continue the collaboration.
"They're an essential partner and ... a lot of the work we need to do as a community in our environment and in our region really does require a partnership."
Mr Collins says the department was stretched before the most recent announcement.
He says the regional council isn't in a position to pick up or pay for the work DoC can't do.