Tucked away in the Botany Department "scullery" sits Emeritus Prof Sir Alan Mark.
Lined with postcards, photographs and other mementoes, it is a tiny room which requires its occupants to fight for knee space among piles of documents - including his tenure review file.
It is just one of the many issues he has tackled over the years.
"I've ruffled quite a few feathers," he admits.
And while he might have retired 11 years ago, recent developments and a change of government means that he still pops into his office most days when not out in the field.
"The changes that are under way right now, or are planned, are absolutely massive. They have huge implications."
He has written to Prime Minister John Key warning him that New Zealand's reputation is at stake.
New Zealand was seen as a leader in the way it handled many environmental and conservation issues, but that image was fast being eroded by proposals such as mining conservation land, ending marine protected areas, creating a big game recreation council and putting an end to South Island high-country parks, he said.
Not to mention the emissions trading scheme.
"Now we're way back and losing ground fast. You could almost despair."
Instead, Prof Mark (77) plans to pick his priorities and go from there - the bonus of being retired and being able to set your own agenda, he says.
"My interests are quite wide. I have a fairly broad interest in environmental issues and play different roles in each.
"I don't resile from it. Life is too short. There's plenty to keep me going."
Despite his opinions on many of the hot topics of the day, including the Project Hayes wind farm and the proposed damning of the West Coast's Mokihinui River, he says since the Save the Manapouri Campaign he had tried to stay away from controversial issues.
"I've thought it unwise to to have a similar involvement."
His involvement in the 1960s-1970s campaign against a proposal to raise the level of Lake Manapouri was his introduction to conservation issues.
It was also a campaign that was later claimed to have created conservation awareness in New Zealand.
But he says that he was invited to get involved in Manapouri by the government of the day, which wanted the university scientists to assess the likely impact of a lake rise.
"I look back and wonder how we got the job. We basically went for it."
While these days he might speak out on behalf of other groups, such as the Central Otago Conservation Group fighting the Hayes project, and Forest and Bird regarding the Mokihinui River, it was not without an alternative in mind.
He firmly believes in the tidal generation capacity of Cook Strait and urges people to support the project to install a prototype generator in the strait.
Throughout his decades of fighting for the environment, he has worked steadily on setting the scene for indigenous grassland conservation.
Thanks largely to the tenure review process, about 15% of New Zealand's original grasslands were protected, he said.
"It's been a hard sell. I never thought I'd see so much protected."
It was important not only for biodiversity values but for water, recreation and landscape reasons, he said.
The production of water was a major issue and information he had got out of research in the Te Papanui Conservation Park on the Lammerlaw and Lammermoor ranges, west of Dunedin, showed the tussock landscape's ability produce water in its natural state was remarkable, he said.
Starting back in the 1960s, the research showed how tall tussock grassland maximised water yield compared with any other land use.
"The runholders were up in arms. For many years, they tried to undermine the whole credibility of the exercise."
Those involved with forests were also sceptical, so a study was set up to compare one area of tussock grassland with another of pine forest.
It showed after time the yield from pine declined steadily.
"They were surprised at the unusually high yields from snow tussock which use water very conservatively."
The work at high altitudes also showed the major contribution of fog to those yields.
However it was very difficult to measure water, let alone the contribution of fog to water, he said.
An isotope chemist was able to confirm the "amazing amount of water" tussock grassland yielded.
"It's a world record in terms of vegetation."
It confirmed the importance of managing and valuing native grassland for water production, he said.
This was the message he took to forums such as last month's Ecological Society of America First Millennium Conference on Water.
However, there were important trade-offs between the value of water coming from the catchment and the value of carbon storage emphasised by the Kyoto Protocols and the Government, he said.
"Our message is: make sure you are aware of the trade-off; that it comes at the price of water."
Water which was becoming increasingly in demand.
People needed to be aware of the consequences before they made the "irreversible" decision to plant in conifers, he said.
"There is still a lot of runholder scepticism on the issue."
Another of his causes was the Mid-Dome Wilding Trees Charitable Trust which had led wilding tree control over thousands of hectares in Southland, making huge inroads to the problem.
"The cost of procrastination is enormous. You turn your back for a year and you've lost all you have gained."
The trust had its origins in a workshop on the high country and the realisation that wilding trees had become too big a problem for any one group to tackle.
At the time, Prof Sir Mark was the chairman of the local Forest and Bird Society and everyone was in agreement that the problem needed addressing sooner rather than later, he said.
"It's going really well although we might be a bit short [in funding] this year."
His interest in water took a different turn when he was appointed a Fiordland Marine Guardian.
The guardians oversee the sustainable management of Fiordland, co-ordinating activities, and have achieved a lot for the sustaining of that magnificent environment, he said.
There were eight marine reserves in Fiordland and all were showing positive effects from their work, he said.
"It's extremely encouraging."
Emeritus Prof Sir Alan Mark
- Born in Dunedin.
- Duke University in the US and a Fulbright Travel Grant.
- Prof of Botany at Otago since 1975.
- Past member NZ National parks and Reserves Authority.
- Past member NZ Conservation Authority.
- Past member and Chair of the Otago Conservation Board.
- Fiordland Marine Guardian.
- Member Mid Dome Wilding Tree Charitable Trust.
- Member Leslie Hutchins Conservation Foundation.
- Patron of the Pomona Island (Lake Manapouri) Restoration Trust.
- Involved Hellaby Indigenous Grasslands Research Trust: first research fellow, then research adviser, and, until earlier this year, chairman of its Board of Governors.
- Life Member and former president of Forest and Bird Society.
- Member of Ecological Society.
- CBE for contributions to conservation - now a Knight of the New Zealand Order of Merit.