Native Grassland: Biomass, Fire, Sheep and Weeds

Project Description

Grassland Resurrection – Connecting Knowledge, Research & Management Forum

 8 May, 2026. Fitzroy Town Hall, Melbourne, Victoria

Presenter: Lincoln Kern

Lincoln is an ecologist with a keen interest in indigenous biodiversity conservation and environmental issues. He trained in botany and environmental science in the USA, before studying environmental management at Deakin University in Melbourne. After gaining experience in Victoria, in 1993 he set up, owns and manages Practical Ecology P/L, an ecological consultancy and restoration contractor and another company implementing biodiversity offsets in rural Victoria.

Native Grassland: Biomass, Fire, Sheep and Weeds
After 30 years of managing native grassland on the Volcanic Plains in urban and rural Victoria I have reviewed extensive science, many management plans and been intimidated by the scale of loss and degradation of good quality sites and restoration works required. Having said all that I have also developed a general approach for monitoring biomass and weeds that informs annual works management based on fire or sheep and weed control. I will review examples of different management plans and sites to illustrate a simple adaptive planning framework required to support restoration and management of the rare ecosystem.

Questions from the Forum

1. Where can we find training to conduct ecological burning at our grasslands sites in City of Melbourne council? We ideally want TOs like the Narrap crew to get on board, but they (as well as other burning organisations) seem too in-demand.
   1. As I understand the situation the CFA or FFMVic will only train their own volunteers or employees. So, training must be obtained through accredited private trainers or RTOs based on prescribed burn curriculum. Practical Ecology got a bloke out of Tasmania named Justin Cashion to train our crew but there are other trainers around the country. On a few occasions in the past 20 years key Council staff have organised training open to their own staff and independent contractors, which could be done again by generous people building skills in the community.

2. When trying to restore a wallaby grass dominated grassland, what would be the ideal time period between controlled burns?
   1. Don’t consider time as the key measure but site condition. Consider burning a Wallaby Grass site as a priority when intertussock space is less than 30%; the goal is to keep intertussock above 30% over time so forbs have space to grow and grasses have room to germinate.

3. Is rainfall since fire a better indicator than time since fire?
   1. It would work to some degree but you would be monitoring by extension a factor that will directly influence biomass accumulation. But wouldn’t it just be better to monitor biomass levels by visual estimate of intertussock space in a grid of sampled points across a site?

4. I’ve heard sheep seem to be more productive feeding on non-native grass (“improved pasture”) and native grass seed has been said to potentially damage wool quality. Any native species would you recommend a farmer?
   1. Apparently, Spear Grasses Austrostipa spp. can be among the worst native grasses for wool contamination. Wallaby Grass species and Weeping Grass seem to be more acceptable in experience but you need to consult real professional sheep farmers. Here’s a website from one of the event sponsors that will provide some guidance:
   2. https://nativeseeds.com.au/native-pastures/

5. If a site has been long-grazed, isn’t it risky to switch to fire?
   1. Yes, it can be risky so the general recommendation is to keep up a similar grazing regime to the past, although it will always be good to avoid grazing in wet winters or spring seed set period, until you establish a monitoring framework and infrastructure, e.g. improved fencing, access tracks, permanent firebreaks where appropriate etcetera, that supports burning AND sheep grazing to manage biomass. Although expert ecological opinion would indicate that burning to manage biomass is better for biodiversity above grazing or slashing there will always be logistical and climactic issues that make it difficult to use only fire so shifting consciously to fire if possible is optimal but using adaptive management principles and being flexible will likely always be necessary.

6. In your view, what is driving variation in grass/biomass reaccumulation rates? Soils? Native vs exotic? Within site hydrology/aridity?
   1. Well, we experienced three very wet La Nina years at Cressy and across SE Australia from 2020 to 2023 and learned that weather conditions supported so many weeds that getting to them all would be impossible while native plants also did very well. Wet years also cause biomass accumulation of course but with sheep grazing being available in the management options we could simply access sheep to manage biomass when it would have been very difficult to burn with ongoing wet conditions. We have also just had a couple quite dry years and the biomass accumulation is quite clearly decreased substantially. Soils and site hydrology would definitely drive biomass accumulation as well. 

7. What method is used to record or measure biomass levels in the grassland?
   1. John Morgan did propose and use the Golf Ball Method as detailed on page 208 of the book Land of Sweeping Plains but this is a labour intensive methodology (cheap student labour helps?) that is more than useful for scientific research. We simplified the method to do visual estimates of intertussock space at 20% increments in m2 sampling plots at regular intervals so that they can be the basis of heatmaps and comparison of biomass levels across a site on an ongoing basis. This is a very quick monitoring process and a little coarse but still more than adequate for making general decisions about biomass management on an annual basis.
8. In addition to germination cues, is there a difference in how burns affect the structure/density of grasslands (ie the quantity/size/distribution of inter-tussock spaces) as opposed to slashing?
   1. First thing to remember is that germination events for forbs can be very limited and hard to observe; grassland forbs persist through time with having strong perennial root stocks. So, fire in grassland may not be a significant factor for germination cues. Secondly, slashing might sometimes be your only biomass reduction option but it can be problematic. The cut grass needs to removed or spread evenly as grass windrows in grasslands kill grasses and cause weeds. Fire is better because it eliminates aboveground plant material and invigorates plants to regrow and flower more substantially.
9. How can you add forbs to a landscape that is under grazing pressure from sheep, or roos?
   1. First, you could try reducing grazing pressure over time or strategically. For example, if you planted forbs in intertussock spaces in winter, excluded sheep until the following or second autumn it would then could be possible to put sheep back in when the forbs have established roots and can tolerate grazing or burning. It could also be possible to reduce roo pressure but that has its’ difficulties. IF you can’t manage grazing pressure then planting forbs in tree guards with sturdy stakes or sturdy wire cages would be the solution. 

10. To Lincoln. Is burning better than using sheep? Don’t you need heat or smoke to encourage germination of native grasses.
    1. As per above burning is a better way to manage grasslands but you don’t need that much germination of native grasses or forbs over time in any event because the grassland ecosystem appears to have flora that perpetuate themselves over time by being long term perennials and occasionally regenerating, quite possibly not needing to do so.

11. Offsets, are generally crap and underwhelming…. How do you mitigate the shitness of offsets ?

I would first ask if you have actually seen or worked on many offsets? Sure, some are probably managed badly or the Offset Management Plan have objectives that don’t drive the high level of quality improvement that some observers might think is required.

However, of the offsets I am familiar with, whether I own them or my clients do, most are well managed in mine and the stewardship manager’s opinion. Please keep in mind that there are significant obligations for management and public scrutiny of offsets. Every proponent that creates an EPBC offset is obligated to post their OMP and annual reports on line; this isn’t true for state offsets but DEECA does have staff random inspecting Section 69 offsets. Any offsets stewarded by Trust for Nature in Victoria are also inspected on a regular basis.  There would be many offsets protected by Section 173 agreements agreed to by Councils that tend to only be enforced by complaint and they will be hard to track in public systems.

It should also be kept in mind that the most important aspect of offsets is permanent legal protection and protection from disturbance with good fencing etcetera; even if issues like weed control and supplemental planting are not implemented well an offset site will in theory still improve from decreased degrading influences and native flora regeneration with opportunity to improve quality by strategic labour always remaining.  For example, an offset protecting large old trees will preserve those even if the groundstorey is a little weedy.   Some offset sites are just “shitness” because of bad choices of site at the beginning; better quality remnant sites make the best offsets because they don’t require much labour to improve and permanent legal and physical protection can be a big win for conservation on sites at risk of grazing or other degradation.

Having said all that IF you see offset sites that seem to be “shitness” then ask questions of the site owner or manager, determine who the stewardship authority AND/OR key regulator (Council, DEECA or Commonwealth) is and ask them if management can be reviewed. There may be privacy concerns but in theory offsets are designed to be publicly accountable and therefore asking questions and driving management review by the responsible parties is more than appropriate.