Vital species live in Carnarvon Station Reserve’s endangered bluegrass grasslands. A new seed harvesting project is helping to ensure their survival in the face of climate change.
Australia has its own bluegrass traditions – and they’ve got nothing to do with playing the banjo. Bluegrass grasslands occupy just under 600 hectares of Bush Heritage’s Carnarvon Station Reserve, Bidjara country in central Queensland – a tiny fraction of its 59,000-hectare expanse. But these scattered remnants of a once- flourishing ecosystem form a vital puzzle piece in the jigsaw of climate resilience.
The grasslands (Dichanthium spp.) are home to numerous native species, some endangered, and are themselves an endangered ecosystem. Chris Wilson, Carnarvon Reserve’s Healthy Landscape Manager, has worked and lived on the reserve with his family for 11 years. He explains:
“The grasslands attract insects, which are the start of the food chain. With those come your birds, your small rodents, your native mammals, and they’re distributing that food throughout the landscape.
"A lot of our critical weight- range mammals, like Northern Brown and Long- nosed bandicoots, live in these grasslands, too.”
“For many species, Carnarvon Station is in a really interesting location in Australia,” adds University of Queensland ecologist Miranda Rew-Duffy, who is in her second year of a PhD studying the effects of fire on Carnarvon's small mammal and reptile species.
“It’s a buffer zone between the semi-arid area and the coastline, and between tropical and temperate climates. The bluegrass grassland is an important ecosystem within Carnarvon for species such as the Narrow-nosed Planigale which makes its home within the cracks of the clay soil, and the Rufous Bettong which digs up fungi and tubers from the fertile soil.”
Yet this vital habitat has been under attack across the Brigalow Belt for hundreds of years, with only fragments surviving. “Because bluegrass typically grows on fertile country, it’s usually turned into cropping country or intensive agriculture,” says Chris.
Carnarvon itself was a cattle station for 150 years before Bush Heritage bought it in 2001, and although it was managed sustainably, dealing with the legacies of that land-use still keeps Chris busy.
His day-to-day tasks include everything from weed and erosion control to feral animal removal and fire management. And, as of April 2020, he’s got a new task to add to that list: bluegrass seed harvesting.
The idea came about because of climate change: specifically, the need to create climate resilience. “Across Australia wildfires are becoming more frequent,” says Miranda. “We’re going to have more hot and dry days which will increase the risk of really harmful, high-intensity wild fire.”
This means that very soon, the areas currently perfect for bluegrass will shrink and change. So Bush Heritage is working on a plan to save the grasslands and establish them in new locations.
To do this, Chris is harvesting bluegrass seeds to sell to local landowners, graziers looking for native grasses, and mines undertaking rehabilitation and offset work. He’s using a brush harvester specially made to work with native seeds, which has minimal impact on the plants.
“It’s like a street sweeper that spins at about 600RPM,” he explains. “Native seeds don’t all ripen at once, so we never take too much seed... ”
"We’re probably only getting between 10% and 15% off the plant. It doesn’t cut or damage the plant; the beaters just tickle the ripe seed off, leaving the unripe seed.”
It’s tricky work. Some patches of grassland can’t be harvested at all because of weed problems, and even the weed-free areas are scattered around the reserve. “It’s a juggling act to be at the right place at the right time with just enough ripe seed, but not having let the plant drop too much seed,” says Chris
Additionally, he says, “The harvest season is at the end of the wet season, so it’s humid. We get dews at night, so we can’t start harvesting until the dew has dried. Then the humidity starts picking up again in the afternoon, so the harvesting window is pretty short.”
Once the seed – which is actually not just one species, but a blend of several native grasses – has been harvested, it must be laid out on tarps to dry, so it doesn’t go mouldy when it’s bagged.
“That’s every afternoon’s job,” says Chris, “to lay the seed out, and turn it every day for a week.”
To add to the challenges, harvest also comes at a particularly busy time of the year that coincides with other seasonal tasks like weed-spraying and burning.
The April 2020 trial run was a success, but there were still plenty of lessons learned for next time. Chris is keen to invest in a bigger harvester, which must be specifically made for the job, and will yield more seed with less impact on the ground.
Bush Heritage is also monitoring the effects of the work on the grasslands, analysing species diversity and soil health both before and after harvesting, so Chris can make any changes that might be required.
Selling the seed, in partnership with Highlands Environmental, has another benefit, of course.
“One of the drivers was to create a sustainable, minimal- impact income stream for Carnarvon, so the conservation can fund itself,” says Chris.
And the hard work is paying off. “The most exciting results I’ve found so far are that the reserve is acting as a refuge for a suite of small mammals and reptiles in the area,” says Miranda. That is, Carnarvon Reserve, together with the adjacent Carnarvon Gorge National Park, forms a wilderness oasis for all sorts of plants and animals in a desert of denuded land. And thanks to the bluegrass seed harvesting project, it’s an oasis that will grow and flourish – even in the face of climate change.
You can help Chris buy a new harvester and bring in more helping hands at harvest time. Donate today.