Ecological restoration: A revegetation ‘lesson’ from Gippsland

By Gabrielle Stannus

Regardless of which vegetation community you seek to protect or restore across our country (there are many that need a helping hand!), there are some basic ecological and social principles to consider if you want your project to succeed. I spoke with a revegetation expert from Gippsland, Victoria, who shared his practical advice with me, learning that the secret to success is as much about the people involved as it is the plants put in the ground.

“Native vegetation can play a part in helping to improve farming life in multiple ways, from the enjoyment of birds and flowers to shade and shelter for stock and slowing water across a farm. We are there to help to implement that,” says Martin Potts, Gippsland Program Specialist with Greening Australia.

Martin’s workplace stretches from the coast to the high country on Gunaikurnai Country in Gippsland, Victoria. “I can be looking at a mountain stream one day and out the next monitoring for frogs in coastal wetlands at night and thinking this is a beautiful place,” says Martin of his revegetation sites, which range from the Gippsland Lakes along Ninety Mile Beach then right up to Benambra. He has been working this ‘patch’ for almost twenty years now, “Some people say, ‘Gee, it is a long time in your job mate’. Honestly, horticulturally, my oldest plantings are still only half the size of the height of the canopy trees that we want to see. The colonising species are only just starting to transform. I feel like I have only had twenty goes at it, twenty seasons, so to speak,” says Martin.

Martin’s slightly self-deprecating humour belies his extensive horticultural experience; he has lived and worked a very full life. He peppers our conversation with interesting anecdotes, including one time when he says he ‘almost starved’ trying to survive on bush tucker in Victoria’s highlands. Moving to Tasmania in his twenties, he landed an apprenticeship with a biodynamic farm. “Learning the rhythms and cycles of how to grow things was really what I wanted to do. There was no hiding, no quick fix to anything,” says Martin of that period. He also studied permaculture, learning from its progenitors Bill Mollison and David Holmgren. Returning to the mainland, Martin then WWOOFed* his way around Australia before managing a biodynamic farm. He studied under Alex Polinsky for several years, growing fruit for Melbourne Market.

However, Martin felt like organic food production was not making the difference he wanted to see, so he broadened his horticultural horizons. He studied conservation and land management, and collected seed and planted for Landcare. He also established permaculture gardens and returned down the bush tucker route, albeit this time a little more successfully! A door opened at Greening Australia, and so Martin began restoring ecological landscapes in line with regional planning and catchment action plans. Martin is currently working to revert the almost extinction of grasslands and grassy woodlands in their natural state in this region and tackling increasing salinisation around the Gippsland Lakes.

Martin and his team have been mapping saltmarsh across the Lake Wellington Wetland with the help of the Victorian Government’s Love Our Lakes Team. “You can now see trees buffering most of the fringing wetlands in that whole district thanks to our last ten or so years. With salt marsh increasing quite quickly there, the salt is encroaching further in, restricting available nutrients in the soils, resulting in their root system completely moving away from the soil. The land therefore collapses in height, which allows the salt to move further inland. This is why we need to bring back the trees. We are also looking to fix some banks and floodgates, or find and enhance springs to make fresh water available again wildlife, whilst still allowing the wetlands to dry out periodically,” says Martin.

According to Martin, wetlands and grasslands can be restored relatively quickly, whereas woodlands pose different challenges, saying “Wetlands are amazing. They respond quickly in a few years. If we get that right indicator species returning, we know that we do not need to plant, or we know whether it is becoming brackish again or starting to freshen up. However, to revegetate a woodland to get the diameter at breast height that will support a healthy canopy forming takes time. In that situation, we are trying to return an ecology that will not have its elders back for hundreds of years yet. So, it is a very slow process. We need to think of revegetation as a future remnant site. How will this tree look when it is an elder and looking after the country around it? Can it connect through the world wide web underground, or is it isolated, and will it only be able to connect through pollination or bird transfer? How does it sit on that landscape in relation to its family?”

Don’t do things in isolation

Martin says that isolated remnant woodland areas suffer, especially those in narrow strips exposed to the ‘edge effect’. One such community, the Gippsland Red Gum (Eucalyptus tereticornis subsp. mediana) Grassy Woodland and Associated Native Grassland, is listed as Critically Endangered under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). To solve this issue, Martin has been looking at pollen dispersal through a meta-community lens, understanding when trees flower, what vectors are dispersing their pollen, and to what extent. He also reviewed academic literature on minimum patch sizes, seeking the help of ecologist Dr Ian Lunt to prioritise his efforts.

“I have met some wonderful people from different fields of study over time. I get to apply their thinking on the ground, and in most cases, I do not have to do the intensive thinking myself. There is a lot of work being done by other people out there, whether they are experts in amphibians and breeding habitats or in grassland management and nutrient control. I will get interested in a topic, and then I will find a researcher or a professor somewhere who is very open to talking to a horticulturist about how to apply this,” Martin explains.

Luckily for us, Martin is also willing to share his knowledge freely, especially when it comes to restoring ecological landscapes: “If you are looking at your area and thinking you would like to do some revegetation, think about your landscape and ask, ‘What did grow here or what is growing here in its remnant form nearby?’. It may be that they are quite a long way apart. However, having a small patch in where you are can make a difference; it might be enough to transfer pollen from one remnant area to another. Now we are talking about actual connectivity and not just a patch that we think a bird might fly through. The trees themselves need increased pollen dispersal. This used to be a connected landscape that is very much fragmented now, and so revegetation in the right place can make quite a large difference just by looking at those vectors.

“To restore some ecological function, you need to find reference areas and then in a sense find them disturbed, find how they are they healing themselves. Looking at the life forms, how much of an area do you have to begin with? Is it a big enough patch size to be able to accommodate self-replication into the future?”

Weeds or trees?

Some sites have had more than their fair share of disturbance, especially when it comes to superphosphate application. When restoring such areas, Martin and his team densely plant early colonising species to outcompete potential weeds that thrive on the excess nutrients left from fertilisers used in agricultural systems. Quick-growing acacias, cassinias, casuarinas, pomaderris and senecios can outpace the many weeds that may otherwise grow in fenced-off paddocks where there is a lack of grazing pressure to pick them out. The photosynthetic products of these plantings also encourage the return of mycorrhizal fungi lying dormant in the soil, thereby contributing to a healthier, more resilient ecosystem able to support the growth of canopy trees.

“Understanding mycorrhizal dispersal and the interconnectedness of potoroos and bandicoots disturbing the truffles, the worldwide web of the connectivity in the root systems of most of our trees and shrubs; we are a long way from restoring that element,” says Martin of landscape restoration. He acknowledges the use of mycorrhizal inoculants in the horticultural industry, “It is a lovely balance bringing some organic processes into revegetation. However, it is still not widely done, and it is not widely understood. I think tube stock and young seedlings would survive better if we understood and could utilise that mycorrhizal relationship in our production lines a lot better.”

Plan vegetation with climate change in mind

Martin and his team put a lot of plants in the ground, and seed collection forms a large part of their work. He plans this collection carefully, avoiding isolated trees whose seeds may lack genetic diversity. “I am currently revegetating four to five hundred hectares a year under trees. I am putting in one to 1.5 million trees a year, mostly by direct seeding. So, seed is a very significant part of what I do; finding the right viability in the right places to get the most vital seed that we can. A paddock tree basically self-pollinates, so you end up with poor seed viability, around twenty per cent of that seed will be viable. So that tree is struggling, it has no potential offspring. You can really see the consequence of the isolation of a paddock tree in its seed viability,” he says.

Martin practises what he calls climate adjusted revegetation, particularly when it comes to seed collection. He collects red gum seed from areas already experiencing temperature stress and water loss to build a drought tolerance into that mix. “When we see this 1.5 degrees (Celsius) temperature increase globally, we will start to see more of the effects of dieback amongst our eucalyptus,” says Martin, “For me, it is about finding those climate variables in our local landscape and making sure that we include some of those genetics into our seed mixes. We are also building in a salt tolerance into some of our plantings around the lakes. Once those lakes blow out and they become marine again, then that salt tolerance is really going to be needed.”

Martin also monitors the landscape carefully, watching for seasonal change to let him know the best time to sow that seed. “Horticulturally, changes in seasons reflect the five or six seasons that the Gunaikurnai and Kulin nations have witnessed for a long, long time. For example, the call of a whistling tree frog or the striped marsh frog first occurs just as the silver wattle comes into bloom on the river, which also happens to be the same time that the swans start nesting in the wetlands. Around the start of August is when the first migratory birds arrive from Japan, the Latham snipe, and the first birds come over the hills as the rufous whistlers turn up. That seasonal change is my trigger to start opening ground up and direct seeding in my sandy country, whereas you hear most people going ‘oh, spring is in the air, isn’t it?’ That is another whole season here that is occurring that we can be aware of hearing those frogs and listening for the sound of the oriel call. We are connecting to Country; we are connecting to that seasonal change.”

Connect people and animals too

This revegetation work is also connecting Aboriginal people with their Country. Martin works closely with the Gunaikurnai and is currently sourcing funding to help improve their women’s wellbeing through spending time together harvesting endangered yams, Murnong (Microseris spp.). “I am working with elders and women to bring up grassland with more yams in them, working with Bruce Pascoe’s idea of disturbance and farming to increase the number of tubers growing,” says Martin, of this edible plant.

In addition to connecting people with Country, Martin says that revegetation done well also restores habitat for other species. “For me, a mark of success is not just the vegetation, it is when we hear that frog, when we see a breeding event occurring in the wetlands. When a lot of my terrestrial work is about five years old, we see the thornbills starting to move in; at seven years, there are silvereyes, and you might get the grey shrike thrush, a rufous whistler or a golden whistler. You can walk under a canopy and hear pardalotes and know that there is a good enough condition for them to be here or a see a Latham snipe flying through the wetland,” says Martin, “Building frog habitat is a key feature in wetland design and we have seen critical numbers monitored at between forty to sixty individual frogs remaining in the Lakes system to now in their hundreds.”

Map and monitor efforts

Communicating success stories is very important in Martin’s work, which is as much about bringing people along for the journey as it is growing trees and other plants. However, sometimes things do not go to plan, and he says it is just as important to acknowledge that. To learn from his projects, Martin maps and monitors his revegetation sites over time. “I make sure that I write down what we are doing because when I am an old man walking my sites, I might see that I got that site ‘wrong’. However, at another site, what we did there is working. You hope that people can see your results and ask, ‘What did you do there?’, Martin explains.

Ultimately, ecological restoration benefits us all, either directly or indirectly. A farmer may gain increased productivity as soil and water quality improves, or a community connects socially to protect a threatened species. Sharing what works or does not work means that the limited resources available for revegetation work can gain maximum impact, i.e. energy is not wasted on efforts likely to fail. I hope you take a leaf out of Martin’s book and share your learnings from revegetation projects with others too.

Note

* WWOOF stands for World Wide Opportunities on Organic Farms, although I thought it meant ‘Willing workers on organic farms’!

Image captions (Images supplied by Martin Potts)

Gabrielle Stannus

Inwardout Studio

M: 0400 431 277

E: gabrielle@inwardoutstudio.com