Fit for the future

In the face of climate change, keeping Bush Heritage’s Yourka Reserve healthy has never been more important. The fates of many species could rely on it.

For many years, spatial ecologist Dr April Reside spent her working days at James Cook University glued to her desk, painstakingly mapping the future. Her research predicts how, by the year 2085, climate change will have affected the distribution of more than 1700 native vertebrate species.

“It was a big undertaking,” laughs April. “The data was immense; the sheer amount of it was the challenging part.”

As rainfall and temperature patterns change, the local climates that many native animals have evolved to survive in will shift or shrink, and those animals will be forced to find refuge elsewhere.

April modelled future climate change scenarios (lower emissions versus ‘business as usual’) to determine which of the 1700 species she studied would have to move, and where they were likely to move to and from.

She found that, like a well-stocked supermarket, some regions will be able to support more animals than others. The protection of these refugia will be critical if we’re to limit the loss of native species in the face of climate change.

Enter the Einasleigh Uplands in far north Queensland, where Bush Heritage’s Yourka Reserve is located on the traditional lands of the Jirrbal and Warrungu peoples. April’s research identified the Einasleigh Uplands as one of the most important refugia in Queensland, reaffirming Bush Heritage’s decision, in 2007, to acquire Yourka so it would be protected forever.

What makes Yourka such a key priority for conservation is the breadth of local climates and ecosystems in its 43,500 hectares, and the sheer diversity of species that those ecosystems support.

“We average 26-28 inches of rainfall a year on the western side, and around 45 inches on the eastern side; we go from temperatures in the mid-40s and 90% humidity in Summer to 13% humidity and -3 degrees in Winter; and our elevation ranges from 580 to 940 metres,” says Yourka Reserve Manager Paul Hales.

Not only do these dramatic temperature, rainfall and elevation gradients make Yourka a biodiversity hotspot now, they make the landscape more resilient to climate change and mean it will likely be a future biodiversity hotspot, too.

By 2085, animals like the Striped Possum, Gould’s Wattled Bat and Southern Brown-bandicoot, none of which are currently found in the Einasleigh Uplands, are predicted to find suitable climate there as their current habitats shift or shrink.

Meanwhile, key species already found in the region, such as Northern and Spotted-tail quolls, will likely persist there.

In the 12 years since Bush Heritage purchased Yourka, the organisation’s management of the reserve has improved habitat for the benefit of its current and future inhabitants.

Significant threats such as weeds, feral pigs and cats are being controlled, while regular controlled burns have opened the forest up to small mammals and reptiles, which are critical prey for larger predators such as quolls.

Paul, who has been managing the reserve since the beginning, sees the impact firsthand.

“We’re seeing Brush-tailed Possums far more often now and we’ve got birds like Chestnut-breasted Mannikins turning up every year; I didn’t see any of them the first eight years we lived here,” he says.

Speaking down the phone from her office in Brisbane, April says preserving Australia’s unique biodiversity boils down to making smart land management decisions, just like Bush Heritage’s purchase of Yourka.

“It’s such a great feeling to know that your work is useful and that there was a point to it,” she says of her research.

“We can do all these fancy models and look at climate space moving, but actually retaining habitat and maintaining healthy populations of species is the best chance we’ve got for their persistence in the future.”