Now in their late 70s, she and husband Terry have downsized and tree changed. She is a retired librarian, he a semi-retired environmental consultant.

Like many Australians of their generation and class, they had money surplus to their needs. And they were at a stage of life where they were wondering what to do with it.

Last year, in a moment of catharsis, the Bellairs decided. They would donate $1 million to convert private property into nature reserves and help create habitat links for plants and animals to adapt to a changing climate.

And in February, 2019, that money officially bought a 203-hectare block of land near a township called Emu.

The Bellairs could have lavished that million on themselves. But the couple lead frugal lives and, more to the point, didn’t feel particularly entitled to their wealth.

"To be quite frank, we've benefited enormously from surplus franking credits, through our self-managed super fund," Terry says.

“It's an outrageous abuse of process, and we didn’t feel we necessarily deserved it.”

The couple live in Castlemaine amid the woods and grasslands of central Victoria, still recovering from the ravages of gold mining and land clearing.

Caroline carries her English accent and is acutely aware of the environmental devastation originally imported here from her country of birth.

So acutely, in fact, it’s enough to make this polite, 70-something librarian’s blood boil.

"If you bugger it up, there's no other planet,” Caroline said

“And Australia has been buggered up so fast, since white settlement…”

“Caroline!” Terry interjects.

“She never swears,” he assures me.

Conservationist Jeroen van Veen stands beside a tree with gnarled bark, dark almost to black. He waits, quiet, until a gust of wind whispers through the tree’s thin, tube-shaped foliage.

“Some people say that’s the sound of Australia,” he says.

If so, it is a sound that was almost silenced.

Bulokes are among the hardest wooded of any tree in the world. The value of its timber and the fact the tree’s range was considered good agricultural land meant it was cleared “by the millions”.

Now, only 3 per cent of Australia's buloke woodland remains, bad news for species such as the red-tailed black cockatoo, which feeds almost exclusively on the bulokes hard seeds.

And those old-growth trees that were spared now cling on as small islands in a sea of farmland.

The 51-hectare block of land on which Jeroen is standing on is tucked away on a dirt road more than an hour’s drive west of Bendigo.

It was purchased in December by Bush Heritage, on Jeroen’s advice.

Previous occupants have left their mark on this place: a native American style teepee made of plaster and a dome-shaped house, now home to swallows and bats.

Buildings aside, the block's dry, heathy woodlands are in good nick.

Pink lady finger orchids grow beneath mature yellow box trees. There are barely any weeds.

Then there are the bulokes. Jeroen pats the trunk of an ancient-looking specimen.

“I’ve been stomping around this area since 1998,” he says.

“I’ve roamed this district far and wide and I’ve only found three stands of buloke woodland like it. Two are on this block.”

By stomping around the area, Jeroen means he has been spearheading Bush Heritage’s efforts to link up isolated bits of habitat around St Arnaud and Wedderburn.

It’s an effort to deal with what Jeroen says is the No. 1 conservation challenge in Victoria: fragmentation of habitat.

But it’s a hidden threat. Species can hang on in pockets of habitat for decades before a bushfire, inbreeding, disease or the arrival of new species seals their fate.

It’s already happened in this place with the black cockatoos, bush stone curlews, bustards, grey-crowned babblers. The list goes on.

Over 15 years, Bush Heritage has bought more than 1500 hectares to connect habitat in what they call the Kara Kara-Wedderburn Landscape.

Though a long-term plan, it’s been given “a sense of real urgency” over the last few years.

“The speed of change we are observing is surprise to us,” Jeroen says.

The weather is getting hotter, the land drier. Some species are moving in, like the scarlet and black honeyeaters. Other can’t travel so easily: sand goannas, stumpy tails, hooded robins.

Jeroen hopes that by linking up pockets of existing land, species will be better able to move and adapt to climate change, as the honeyeaters have.

The Bellairs heard Jeroen’s plan at a Campbells Creek Landcare meeting last year.

The next day, they began the process of donating a million dollars to Bush Heritage.

“We'd left them a bequest in our will, but then they'd have all the fun of deciding what to buy,” Caroline says.

“I thought it would be much more fun to help choose it, and then we could follow what was happening and see how it progressed.”

Bush Heritage also hopes to buy another nearby block with the Bellair donation which will help form a chain between Wedderburn and the Kara Kara National Park.

The Age