Since 2001, Carbon Positive Australia has collaborated in the revegetation of over 5,000 hectares of degraded land. Our restoration projects are all individual, with each site needing a slightly different approach depending on where it is situated, the diversity of native plant species, and the rainfall expectations.
“It takes a little bit of art and a little bit of science,” says native plant agronomist Geoff Woodall. Geoff has been working with Carbon Positive Australia since 2009. He has worked to improve seed treatment, the machinery we use, seeding methodology and weed control. His knowledge gained over many years of restoration work and carbon farming projects ensures the survival rates of the trees we plant. During a recent drought at Eurardy, a site where we are collaborating with Bush Heritage Australia, the landowners have seen survival rates of upwards of 90% (without watering) thanks to Geoff’s expertise.
Preparing the seeds
It all starts with the collection of seeds. Because we use only local native plants, we need to gather the seeds from the areas where we plant. Seed collection is an essential part of the planting process.
“Not every year is a good year for seed collection. It’s either feast or famine. So we collect as much as we can and keep the seeds in storage for several years until we need them,” says Geoff.
After collection, preparation of the seeds ensures their rapid and uniform germination. To break the inherent dormancy of the endemic native seeds, they are commonly boiled or smoked. “This happens in a big smoking room”, explains Geoff. “We create smoke from burning leaves and other materials. For big scale projects like Eurardy on Nanda County in the Northern tip of the WA Wheatbelt, this preparation process alone can take up to several days. You must realise we’re dealing with millions of seeds here.”
Some species, including Eucalypts and some Melaleucas, are not suitable for direct seeding. Those seeds are germinated in accredited nurseries for up to six months until seedlings are ready to be hand-planted in the winter months.
Next is the preparation of the soil for seeding. “The soil is scalped and ripped, and the seeds are put in with a machine. This is obviously more cost-effective than planting by hand,’ says Geoff. “Our success depends on putting together an ideal package of different seeds that are best suited to the soil conditions.” On average, about 400 grams of seeds are needed to cover 1 hectare.
What sets our approach to revegetation apart is our exclusive use of local native systems.
“Other revegetation projects are monocultures, mainly mallee based,’ explains Geoff. “You don’t find as much diversity in the plants there, and ultimately in the other species that are attracted by it.”
On average, each hectare planted at Eurardy will remove an estimated 120 tonnes of carbon over 25 years, supporting Carbon Positive Australia to assist companies and individuals in reducing their carbon footprint.
More About Eurardy Reserve
The goals for Eurardy are about much more than just carbon sequestration. The previously grazed land is being restored back to its natural state. Before its protection in 2005, the Eurardy site was used as a pastoral lease, of which over 2,300 hectares had been cleared for agriculture and grazed extensively for decades. This changed the landscape, and entire ecosystems were modified and degraded. Other land degradation occurred with the loss of vegetation, including fragmentation of habitat, dryland salinity, erosion, low soil seed bank levels, and chemical residue from fertilisers remaining in the soil.
Eurardy protects more than 500 plant species, including five nationally endangered or vulnerable species. The reserve also forms a crucial ecological linkage between the Kalbarri National Park to the west and the Toolong Nature Reserve to the northeast. By planting what used to grow here, we hope that these plants will then set their seeds to the wind and eventually develop naturally self-sustaining habitats and ecosystems.
Eurardy was recently in the direct path of cyclone Seroja and was evacuated. The individuals from Bush Heritage Australia are safe and well, and the damage to the site, thankfully, appears initially to be minimal. We are living in a world where climate change is driving wilder weather and, while this one in 50-year event may, of course, have not been due to climate change, we know that weather events like this are going to get more common as our planet heats.