Biodiversity Set to Flourish at Weelhamby

We last updated you on the Weelhamby project back in June 2022 after the Wheatbelt property was direct-seeded and planted with over 70,000 mixed native seedlings.  

Weelhamby Farm,a 5,500-hectare property just outside Perenjori,combines a 3,200-hectare soil carbon project with 230 hectares of environmental planting. It aims to demonstrate the potential of carbon markets to improve farm productivity, build new income streams and attract diverse flora and fauna to the hot, dry landscape of the Wheatbelt. 

A recent survey of the reforested project areas by Dr Dan Wildy of Woodland Services revealed a whopping 960 trees and shrubs have survived on average per hectare, despite the recent dry conditions in the region. Some patches of clay or cloddy soil showing lower establishment rates will be replanted to ensure adequate forest cover. The results are great news for the project and demonstrate the value of well-designed plantings to sequester carbon and boost biodiversity in even the most challenging environments.  

Image: a mixed seedling and direct seeding area (Credit: Dan Wildy)

For David, building biodiversity above and below ground was “a major consideration” in designing the project. Rejuvenating pasture paddocks by maintaining year-round ground cover, rotational grazing and introducing multi-species pasture and crop mixes will build soil organic carbon which will, it is hoped, boost microbial diversity. “Microbial biodiversity is critical to the cycling of nutrients and carbon and the long-term sequestration of carbon”, David said. 

Planting local species in small strategic blocks and along paddock edges creates corridors to provide habitat for native wildlife, along with a variety of other benefits: “From a revegetation perspective, our plantings were designed for both landscape management (wind breaks, erosion control, livestock shelter), as well as creating wildlife corridors that link existing pockets and larger areas of remnant vegetation. Our property is surrounded on three sides by nature reserves, so the corridors will hopefully become an important linkage between these reserves.”

Image: Soil carbon and reforestation areas at Weelhamby

The wildlife corridors are woven throughout the property, linking 1,500 hectares of the farm’s remnant vegetation to the surrounding nature reserves. The remnant vegetation has been fenced off, allowing it to recover from past grazing practices.

“For smaller animals and birds, the plantings will provide valuable refuges and transit routes between larger areas of remnant vegetation and the adjacent nature reserves. We later discovered that there is a Threatened Ecological Community (TEC) – the Koolanooka Hills – on our property that has been fragmented by clearing, and the future plantings that we are currently investigating will provide important linkage to rejoin and provide buffers for this TEC”, David said.

Image: Establishment of direct seeding (Credit: Dan Wildy)

With the introduction of new markets for biodiversity credits, the myriad methods of measuring biodiversity improvements are the topic of much discussion. “[For the Weelhamby project], we engaged an ecologist to do detailed baseline studies of the flora across key sections of the property. We will update this study every 3 to 5 years to see what changes are evident and get an idea of whether interventions are required to improve biodiversity outcomes.”

The project is not currently registered with a biodiversity credit schemes, but David sees biodiversity credits as a useful complement to carbon credits: “It is important to incentivise landholders, particularly in the Wheatbelt, to protect and rebuild biodiversity. One of the biggest financial impediments to revegetation projects is that the revegetated land ceases to have any commercial value once the plantings are done, beyond the value of the ACCUs generated. Biodiversity credits would encourage the right type and layout of plantings and provide an important economic incentive to manage areas for biodiversity.” 

It’s still early days for the soil carbon project, but we’ll keep you posted on preliminary results as they become available. Watch this space for more information as the Weelhamby project progresses!