Kevin Smith, senior adviser to Conservation Minister Chris Carter and former conservation' />

One of New Zealand's foremost conservationists has died.

Kevin Smith, senior adviser to Conservation Minister Chris Carter and former conservation director of the Royal Forest and Bird Society, was 51.

He has been credited as playing a major role in conservation efforts in New Zealand, including being instrumental in ending the logging of native forests on the West Coast.

Mr Smith began working for Forest and Bird in 1984 and became conservation director in 1989. He left in 2000 to become advisor to the then Conservation Minister Sandra Lee.

Kevin Hackwell, current conservation director at Forest and Bird, said Mr Smith was crucial to the development of conservation ideals here.

"He's played a huge role in conservation efforts in New Zealand," Mr Hackwell said.

Mr Smith became committed to conservation at a young age.

"He was brought up in the little North Island settlement of Owhanga, just north of National Park. His father was the bush foreman for a mill there, logging native forests," Mr Hackwell said.

He did a conservation degree in botany at Canterbury University and began a PhD on forest ecology on the West Coast.

"But he gave it up, he felt he couldn't be doing the science and a PhD while the forest was being logged all around it," Mr Hackwell said.

Mr Smith's history with Forest and Bird began on the West Coast in the tiny settlement of Hari Hari, a forest service milling town in South Westland.

"That was a very hostile environment for a conservationist to be active in," Mr Hackwell said.

"But he held his ground and was one of the two public faces of conservation in South Westland."

He advocated an end to logging of native forests on the West Coast, and also helped run a campaign on central North Island forests.

Mr Hackwell said one of Mr Smith's legacies that went well beyond just conservation was the issue of New Zealand's biosecurity.

"He was really, and accurately, a strong critic, a fierce critic of our slack biosecurity throughout the '80s and '90s," Mr Hackwell said.

"At one stage Lockwood Smith accused him of economic treason because of his advocacy for better, tighter biosecurity.

"But Kevin was absolutely on the dot there and he continually showed up how bad our biosecurity was and how important it was, not just for conservation, but for our primary production, agriculture and forestry."

He alerted farmers and foresters to the issues and his strong advocacy led to a complete overhaul of biosecurity regimes.

"We have a whole new way of doing it and it is a thousand times better. That is very much an issue that is reflective of his fantastic advocacy on that."

It was "crucially important" for New Zealand to have people like Mr Smith who would stand up for what they believed in, he said.

"He was not afraid to argue the toss and to take what were often publicly unpopular positions and to advocate for New Zealand's biodiversity, for our wildlife, for our forests and say 'nobody else is doing this and we need to'."

New Zealand was a better place for it, Mr Hackwell said.

"When you think about it now, our tourism industry is our single largest industry -- that is based so much on our clean and green image, on the national parks and reserves that we have.

"So much of that we've got and secured in the last 20 to 30 years with Kevin's advocacy and leadership of organisations like Forest and Bird."

Outside of work Mr Smith was an avid mountain biker and "phenomenally fit", Mr Hackwell said.

"He was very dry, sometimes quite gruff but with a wicked dry sense of humour that went with it."

Mr Hackwell fondly remembered seeing Mr Smith at meetings, poring over what everyone assumed to be the agenda and other important papers, only to glance over and see he was actually examining Best Bets.

But most of all he was a man who made a difference.

"He was very sharp, could cut through the crap, could go to the core of what the issues were really quickly," Mr Hackwell said.

"He came across at times as the lad from the country, which he was, but he was really spot on."