More than 52 million hectares of Australian land—an area equivalent to eight times the size of Tasmania—is degraded, with severe implications for biodiversity, ecosystem services, and human well-being. In 2022, Australia committed to the Global Biodiversity Framework (GBF), pledging to restore 30% of this degraded land by 2030, which equates to roughly 15.6 million hectares. Achieving this ambitious goal requires restoring native vegetation, particularly through biodiverse plantings that form resilient ecosystems.
Planting diverse native species is essential for successful ecosystem restoration, but Australia currently faces a critical shortage of native seed—especially for understorey species like grasses and herbs, which are fundamental to ecosystem function. Research from our group at Western Sydney University shows only about 10% of the country’s 25,000 native plant species are readily available as seed for restoration (Andres et al. 2024). Most of this seed stock favours woody species like eucalypts and acacias, which are prolific, easy to harvest and store, and are in high demand due to reforestation and carbon offset initiatives.
This seed supply imbalance undermines restoration efforts by disproportionately favouring canopy-forming species while neglecting understorey plants, which are often where true plant diversity lies (Andres et al., 2023). Further, restoring trees does not automatically lead to the return of understory diversity, particularly in ecosystems like grasslands or critically endangered ecological communities, such as the Cumberland Plain Woodland on our campus at Hawkesbury Institute for the Environment.
To address this issue, our research team recently assessed the seed in supply across six major Australian vegetation types using data from 32 commercial suppliers. We found significant gaps between the diversity of species available and what is needed to reflect natural ecosystems. In particular, the lack of herb and grass seeds dilutes efforts to recreate functional, representative vegetation.
In response, we developed a framework to optimise seed mixes based on functional traits—like plant height and leaf size—rather than simply aiming for taxonomic richness. Adapting this trait-based approach can help practitioners target essential ecological functions, such as pollination or nutrient cycling, even when seed availability is constrained enabling better outcomes from limited seed stocks (Andres et al., 2024).
Still, real challenges remain. Many native species are not included in restoration because their seeds are hard to collect, store, or germinate. Moreover, restoration projects often prioritise species that are easier to monitor remotely using satellite imagery, such as trees, whereas detailed understory recovery requires labour-intensive, on-ground assessments.
To meet our national targets for restoration and reverse biodiversity loss meaningfully, Australia must drastically improve its seed supply infrastructure. We may do this by expanding seed production areas—such as dedicated ‘seed orchards’—to produce difficult-to-source species sustainably. This reduces pressure on wild populations and improves availability. Also, increased investment and national coordination are crucial to building a robust seed sector, especially for small-scale suppliers who could support greater diversity. Collaboration across all levels of the supply chain—from scientists and seed collectors to financiers and volunteer groups—is fundamental to fostering a deeper understanding of the seed supply bottleneck and expanding the palette of available species. This may also include actively ‘designing’ vegetation tailored not just to mimic historical reference sites, but to target the reinstatement of ecological functions or the needs of higher trophic levels, such as supporting pollinators or threatened species.
Finally, it is imperative that we protect existing intact ecosystems from clearing. Given factors like seed limitation, restoration cannot always replace what has been lost. Therefore, protection must come first, and restoration should be grounded in an understanding of both ecological goals and practical constraints. Australia needs an ethical, scientifically informed, and well-resourced seed supply chain to achieve its restoration ambitions. Without this foundational resource, the goal of restoring 30% of degraded ecosystems risks becoming unachievable. By making every seed count—prioritising diversity, function, and sustainability—Australia can rebuild resilient, biodiverse landscapes.
Rachael Gallagher
Associate Investigator, Western Sydney University, Hawkesbury Institute for the Environment
References:
Andres, S.E., Atkinson, J., Coleman, D., Brazill‐Boast, J., Wright, I.J., Allen, S. and Gallagher, R.V. (2024). Constraints of commercially available seed diversity in restoration: Implications for plant functional diversity. Plants, People, Planet.
Andres, S.E., Standish, R.J., Lieurance, P.E., Mills, C.H., Harper, R.J., Butler, D.W., Adams, V.M., Lehmann, C., Tetu, S.G., Cuneo, P., Offord, C.A. and Gallagher, R.V. (2023). Defining Biodiverse reforestation: Why It Matters for Climate Change Mitigation and Biodiversity. Plants, People, Planet.
