An "unusually hot" March this year could spell bad news for native wildlife in the country, according to the Department of Conservation (DoC).
The warmer weather is predicted to lead to an increase in the chance of beech forest seeding next summer in parts of New Zealand, which can fuel an upsurge in rodents and stoats and be "bad news" for native wildlife, DoC said.
DoC's principal scientist Dr Graeme Elliot says the prediction is based on data from NIWA's virtual climate station network, with the modelling showing beech seeding, or masts, is "very likely" in Fiordland next year. It may also occur in north Otago, south Westland and north Canterbury.
"After a couple of years with little beech seeding anywhere, it's looking like there will be a beech mast in a handful of places around the country in 2022," Dr Elliot said on Tuesday.
"Although this past January and February weren't especially warm, March was unusually hot in some places, which increased the overall summer temperature."
He said DoC would be monitoring flowering next spring using satellite imagery, and in summer would sample seed in some forests to confirm where a mast is occurring.
The department would also be monitoring rodents and stoats, with predator control operations to take priority in order to protect "our most vulnerable wildlife", Dr Elliot said.
The latest prediction comes after a "megamast" occurred in 2019, which scientists said was the most widespread seeding in 40 years.
In that case, DoC responded with predator control operations covering a record 908,000 hectares.