Row upon row of parallel furrows snake their way towards the horizon, cutting deep red lines through the weedy wheat paddock that welcomes visitors to Bush Heritage’s Eurardy Reserve in Western Australia.
It’s perhaps not the entrance you’d expect to find to a conservation reserve, but then, these rip lines aren’t awaiting your standard crop either.
As Bush Heritage ecologist Ben Parkhurst, his wife Tina Schroeder and their 10-month-old son Liam look on, the first of over 36,000 native seedlings are planted in the loamy, moist soil.
The planting is part of the first phase of an ambitious project that will eventually see over 1350 hectares of cleared land on Eurardy restored — Bush Heritage’s largest revegetation project to-date.
Located six hours drive north of Perth, the 30,050-hectare reserve on Nanda country has two major soil types: sandy, nutrient-poor yellow soils and denser red soils. In some places, the transition between the two is so abrupt that the ground takes on an ombre appearance.
Under previous owners, around 750 hectares of Eurardy’s red soil country and 1550 hectares of its yellow soil country were cleared for cropping and grazing; the remaining 27,750 hectares were left relatively undisturbed.
Since Bush Heritage’s purchase of the reserve in 2005, its uncleared land has flourished thanks in large part to the organisation’s work controlling erosion, rabbits, foxes and feral goats. But the cleared areas have remained stubbornly barren.
“We’ve tried natural regeneration for almost 15 years, but it just hasn’t happened,” says Ben. “There's fertiliser residue in the soil that makes it unsuitable for native species, the seed bank is really low, and native plants can’t compete with introduced agricultural weeds. Active revegetation is our only option.”
The first phase of revegetation is expected to take five years and will focus on restoring Eurardy’s red soil country, which supports one of the northern-most stands of York Gum (Eucalyptus loxophleba) woodlands.
York Gums were amongst the earliest and most heavily cleared of the eucalypt woodlands in the West Australian wheatbelt because they grow on more agriculturally productive soils. Around 10% of their original cover remains.
“Eurardy is one of the last larger areas where there’s lots of intact York Gum habitat,” says Tina, who is investigating how to restore York Gum woodlands as part of her PhD.
The decision to start with the red soil and not the yellow is a calculated one. Eurardy’s yellow soils support Kwongan Heathland, a globally significant and threatened ecosystem that features an enormous variety of plant species, making it difficult to restore well.
Restoration techniques for eucalypt woodlands are comparatively simple and much better researched; however, they’re still not cheap. Ecological revegetation can cost up to $2500 per hectare, meaning the total cost of restoring Eurardy’s cleared red soil could be upwards of $1.8 million.
To overcome this otherwise prohibitive cost, Bush Heritage has partnered with the Carbon Neutral Charitable Fund (CNCF), a not-for-profit that specialises in high-quality, biodiverse revegetation. In turn, CNCF provides its customers with carbon credits to help offset their environmental impact.
In July, a team of CNCF contractors donned buckets of seedlings and bright red tree planters to individually place 36,000 seedlings, comprising seven species of eucalypt and melaleuca, in the cleared paddocks at Eurardy’s entrance.
CNCF estimates that more than one million trees will be planted on the reserve before phase one is complete, capturing more than 90,000 tonnes of carbon dioxide — equivalent to removing 20,700 passenger vehicles from the road for a year.
It will be over a century before the revegetated areas are fully functioning ecosystems. As the trees mature and limbs drop off, hollows will form and provide nesting places for Red-tailed Black-cockatoos (Calyptorhynchus banksii) and other birds. The fallen logs, meanwhile, will offer shelter to ground-dwelling species such as the endangered Western Spiny-tailed Skink (Egernia stokesii badia).
At this stage in their lifecycle, Ben says the trees take on a “twisted, tortured gracefulness that’s really quite beautiful.”
Ben and Tina hope to complement CNCF’s plantings with direct seeding of understorey species and experimental work to restore the ground layer of annual herbs — something that has never been attempted.
As part of her PhD research, Tina has also been investigating how adding logs and other woody debris to restored sites could assist with the recovery of soil health and invertebrate communities.
And then there is the challenge of phase two, restoring the cleared yellow soil country, which is due to start in 2021.
It’s a massive project, but as Tina watches the first plants go into the ground with Liam on her hip, she muses that her son is a reminder as to why it’s all worth it.
“Now, with our little one, it really feels like we’re doing something for the next generation,” she says. “Liam loves being outside. He loves the trees, he loves looking at the leaves, he loves listening to the birds. We probably won’t live to see these trees reach maturity, but Liam might.”