After Tuesday's swearing in of Gladys Berejiklian's new ministry, the Premier defended her decision to hand heritage to the arts minister, and move environment into the broader planning portfolio.

"Along with energy, it [the environment] will be a key focus of the government," the Premier claimed.

While she reassured staff and the public that the independence and services provided will not be compromised, the National Parks Association's Far South Coast branch president, David Gallan, said he can understand the "anger" of staff, who took to social media groups to air their grievances.

"Overall, the past actions of this government give the public little confidence that the environment will be properly protected in the future," he said.

"We know national parks staff have been suffering low morale for years after constant restructures and job losses, leading to lack of certainty in career paths, job security and the loss of firefighting capabilities.

"Hearing the Premier say environment staff would have 'a prominent place within planning to make sure every decision we take considers the environment', implies that this hasn't happened in the past. And we know that. It's no secret that time and time again advice from experienced and eminent scientists is ignored."

When asked if the running of national parks will be affected and if further job losses can be expected, a spokesperson said functions currently provided by OEH "will continue under the new government structure and outcomes for the environment will continue to be delivered".

"Changes to individual government agencies such as OEH will in no way change our staff's commitment to delivering on the environmental priorities of this key portfolio," they said.

According to Bega Valley Shire Council, 40 per cent of the local government area consists of national parks, and a quarter is state forest.

OEH chief executive Anthony Lean said this week in a letter to staff he is "seeking clarification" on the government's changes.

Nature Conservation Council CEO Kate Smolski said in a statement this week, the Coalition government "has been at war with nature and environmental protection since it came to power in 2011".

Ms Smolski said the gutting of the office "appears designed to reduce it to providing back-office functions enabling development".

"Protection of nature and the environment is so important it needs a separate department. It should not be subordinate to the development and industrial complex," she said.

"Our unique wildlife and landscapes need a strong, independent advocate within government standing up to the relentless pressure of the mining and developer lobby.

"The only way we to ensure this is to establish a separate department distinct from planning, industry and energy."

Mr Gallan said he does welcome the decision to give the Environmental Protection Agency "more grunt" due to it being what he describes as "grossly understaffed".

He said the work of science should be at the forefront of government decision making, which has included the recent "roll over of the 20 year Regional Forest Agreements without a proper and independent scientific assessment".

"The threats to de-gazette a national park, log in national parks and raise the Warragamba Dam wall are deeply concerning," he said.

"The catastrophic mismanagement of the Murray-Darling has received a highly critical report from the Australian Academy of Science.

"Our local forests are being described as 'matchsticks' by a leading commercial beekeeper. Clearly the use of our natural resources is not sustainable.

"Key native species populations are crashing and former forest protections such as stream bed reserves are now being halved. These stream bed reserves are vital for threatened parrots, owls and gliders."