Ashes to orchards

How the Black Summer bushfires kick-started a restoration revolution at Scottsdale Reserve.

There is no denying the flames of the 2019/20 south east Australian bushfires were horrific. “There was grief, without a doubt,” Scottsdale Reserve Manager Phil Palmer says.

Approximately 73% of the 1328-hectare Scottsdale Reserve, about an hour’s drive south of Canberra, was incinerated, including thousands of newly planted trees on the reserve’s valley floor.

“It looked terrible. Every single tree we’d planted had been burnt off to the ground and was sitting in a melted blob of its plastic guard.”

“I felt quite defeated. It took an evolution of thousands of years to create these plant communities and it was lost... gone,” Phil says.

But this is not a gloom and doom bushfire story. Not only have many of those seedlings now resprouted, but post-fire surveys also identified a number of ways to increase plant survival and the need for large quantities of native grass seed has kickstarted an innovative project that will help to ensure the long-term restoration of Scottsdale’s grasslands.

After purchasing Scottsdale in 2006, Bush Heritage began what was always going to be an ambitious project: restoring the reserve’s critically endangered temperate grasslands.

“Our energy is concentrated on restoring the 600-hectare valley floor, which when farmed comprised many small paddocks for cropping and grazing. Parts were heavily tilled and the soils highly depleted. As a result, the weeds moved in and the landscape became dominated by African Lovegrass (Eragrostis curvula),” Phil says.

Bush Heritage took a multi-pronged approach to restoring Scottsdale’s valley floor. Trees were planted and seed production sites established but control of the African Lovegrass proved difficult until the introduction of Flupropanate, a selective herbicide that has minimal impact on native species.

“Flupropanate proved to be a cost-effective and efficient way of managing Lovegrass, but we were being left with enormous amounts of rank [dead] grass,” Phil says. “It was like a scab across the landscape that was stopping everything else from growing.

Enter the fire. Along with the destruction of planted trees and remaining natives, the flames consumed the Lovegrass, baring the soil once again.

Such was the extent of the fires that the government and private donors stepped in with a range of financial incentives for recovery work. Bush Heritage was able to access the Bushfire Recovery Grants Program, jointly managed by Landcare Australia and the National Landcare Network and supported by the Australian Government’s Bushfire Recovery Program for Wildlife and their Habitat. The Volkswagon Australia Group also generously provided a private donation for bushfire recovery at Scottsdale.

The fires and their aftermath were about to kick-start a restoration revolution for Bush Heritage.

“We could have used the funding to purchase native grass seeds and put them into the understory in the hope they would colonise, but native seed is rare and incredibly expensive - up to $2200 per kilogram,” Phil says. “We decided that we would invest that resource into a seed orchard instead with the idea of harvesting our own seed annually.”

Grass seed orchards are a relatively new practice in Australia, but this did not deter the Scottsdale team.

Two native grass seed orchards were established: two hectares of Red-leg Grass (Bothriochloa macra) and five hectares of Kangaroo Grass (Themeda triandra). Bush Heritage ecologist for South-East New South Wales Brett Howland takes up the story.

“These two grasses are fairly tolerant of Flupropanate and are both keystone species in our box grassy woodlands. Red-leg Grass is a very good coloniser and you can get a good crop up pretty quickly so it is our first wave of defence. Then Kangaroo Grass is the opposite. It’s not very good at colonising, but once you get it in place, it’s a really good competitor and can be a transformer, securing nutrients, increasing soil biological interactions and holding onto the ground. Intact Kangaroo Grass area can prevent weeds like African Lovegrass from coming in.”

The Scottsdale team has been implementing the seed orchard project using adaptive management principals, experimenting with different sowing rates and weed control methods such as slashing and burning. It’s not every day that a conservationist sets out to grow a monoculture but Scottsdale’s fledgling, innovative orchards are providing hope for large-scale restoration.

Trials, monitoring and improvements will continue and, with favourable weather conditions, it is hoped the first Red-leg Grass seeds will be harvested in 2023 and the first Kangaroo Grass in 2025.

Initially, they’ll be used to increase native cover in fire and weed-affected areas of the reserve.

“The key message is that native grasses are worth their weight in gold and preserving them is an absolute priority, because reconstructing grasslands on a large scale is both difficult and expensive,” Phil says.

“Restoration is not rocket science; it’s harder. There is a lot to consider including seed dormancy, soil preparation, crop protection, weed management and harvest techniques.”

Trauma has been superseded by opportunity at Scottsdale. “The bushfire set things in motion. It broke the drought, it cleared up the Lovegrass ‘scab’ and it provided us with resources and energy to trial new things and take bigger and bolder steps on a large scale,” Phil says. “Without the support of post-fire grants and our Bush Heritage volunteers, who provided much of the on-ground labour, we would not have established our first native grass seed orchards.”