Project Description
Grassland Resurrection – Connecting Knowledge, Research & Management Forum
8 May, 2026. Fitzroy Town Hall, Melbourne, Victoria
Reimagining urban transport and utility corridors to restore and connect an endangered ecosystem.
Authors: Nicholas S. G. Williams, Zahra Saraiean, Sophia Blosfelds Ben Roberts Katherine Horsfall
Urban road, rail and utility corridors sometimes contain small fragments of remnant ecosystems but what if they could form a connected network supporting significant biodiversity. We are working with municipal governments, Metrotrains and Yarra Valley Water to reinstate species from critically endangered grassy ecosystems to urban corridors. Ecologically this has been achieved by developing methodologies to sow diverse species mixes, on to low nutrient preferably recycled construction wastes selected after careful evaluation. This allows projects that span the ecological restoration continuum, from highly designed urban green spaces to a vegetation community that mimics the adjacent endangered native grassland.
Presenter
Nick Williams is a Professor of Urban Ecology and Urban Horticulture at the University of Melbourne and in his spare time he is also the President of Friends of Merri Creek. After spending much of the past 15 years researching ways to get biodiversity on to city buildings via green roofs and walls, he has returned to his academic roots and now leads a large research program developing new restoration and conservation technique for urban native grasslands which were the subject of his PhD. This continues the pioneering native grassland restoration research conducted at the University’s Burnley Campus by PGR and John Delpratt.
Questions from the Forum
- I predict that the slashing machines that are slashing these utility corridors are slowly destroying them by introducing weed seed eg Sth African Weed orchid. Is this on the radar of powercor, vicroads etc?
- Weed hygiene is big issue particularly for Nassella species etc and needs more awareness. SAWO spores just blow everywhere on the wind so I don’t think slashing is the culprit
- What’s the biggest barrier to rolling out more cap and sow?
- Seed supply and coordinating the supply of a low nutrient substrate particularly if this is to be subsoil. Recycled products such as crusher dust (Basaltic Sand) from RepurposeIt have advantages in this respect
- How do per hectare costs compare to scrape and sow?
- This is incredible dependent on numerous factors but in general removing soil is incredible expensive if it has to be transported any considerable distance so capping should be cheaper particularly if we can charge construction companies to do so – they may otherwise be paying landfill disposal costs etc
- What sort of scaling issues are you finding with seed production?
- Not sure yet but the industry definitely needs reliable sources of seed that can be driven by long term contracts from government and infrastructure developers
- Are there other recycled construction materials beside basaltic sand that have potential as a capping material?
- Yes subsoil
- Have you seen potentially rare soil profiles of local provenance such as VVP, heavy clay type basalt sub top soil layer, be re-used by an LGA or other government body?
- Not yet but Metro did. Not sure why you think they may be rare?
- How much of the grassland predicament is a marketing problem. Nick’s work has great educational potential for city folk.
- I wish the conservation movement would stop focussing on tall forests (which are incredibly well protected in reserves) and spend more time advocating for critically endangered ecosystem like native grasslands and other incredibly fragmented and rare ecosystems in agricultural and urban regions – although there are exceptions GPN, VNPA, Friends of Grasslands in the ACT etc. Lots of research has shown native grasslands have an image problem. We refer to them as wildflower meadows and emphasising the flora diversity and abundance in restorations to help change this
- What is the best method to tackle kikuyu in established grasslands?
- Multiple herbicide applications during its growing season – generally spring – early summer but this is rainfall dependent. Its difficult!
- Nick, how do you go finding suitable capping material WITHOUT the usual disturbance/construction site weeds?
- You insist that it is from below 0.5 m in depth and is clean – lots of due diligence and chain of custody required
- RE the recycled clay soil for cap and sow, can the recycling be done on site in future, to keep costs down? Eg restoring an easement alongside a housing estate.
- Yes ideally this would be the case as it will reduce costs. Short term stockpiles of subsoil should be OK and Metro has used this approach at Sunbury. It alleviates the need to match timing of a development with sowing
- how do you source your seeds, are they wholesalers or do you work with teams (with approval) to forage them? If so do you find one more generally successful than the other?
- We grow all our wildflower seeds ourselves in a dedicated Seed Production Area at Burnley and buy our grass seed from native seeds. Wild harvest is not sustainable from a conservation perspective and the seed quantity and quality is lower
- What is the ideal amount of seed in kg to spread in an acre to get best results ?
- 2-5 g / m2 See Land of Sweeping Plains restoration chapter
- Now that we have a few successful examples of cap and sew, how quickly can these projects be rolled out? Is it set and forget, or ongoing maintenance in perpetuity?
- All landscapes require maintenance so it is not set and forget but over time maintenance costs come down.
- What sort of density for direct seeding was used for the sucessful grassland research projects? Did it differ between sand/subsoil?
- See above. It differs depending on the project.
- Is bare earth better for spreading seed than a mulch layer ? What advice would you give for spreading grass seed in an area that has had forestry mulcher breakdown woody weeds on leaving behind wood chips above soil ?
- Spreading seed on a thick layer of mulch will not work, which is why you see no / very little recruitment in mulched planting areas
