A walk in Yalukit Willam
I went to Yalukit Willam Nature Reserve. A rare example of a new nature reserve being retrofitted into suburbia Melbourne. It was previously a golf-course that shut down due to (from what I can tell) not being financially viable anymore. So the council bought it and are in the process of constructing a new nature reserve. Not all is open yet, with just two areas open to the public, the Chain of Ponds and Wildflower Meadow (that previous was called 'the grasslands') as viewed on the masterplan map here.
This whole idea of 'constructing nature' is really interesting. In reality this just means a lot of earthmoving and landscaping works. I mean it was a former golf course so its not like the area was previously completely devoid of nature. It's a bit crude to say 'constructing nature'. The process is known as ecosystem restoration because there is an understanding that we're restoring the ecosystem(s) that existed here prior (usually the case). But it may even be that we are restoring an ecosystem(s) that never existed in the first place. But regardless, that idea of humans can undertake processes to restore ecosystems is still important to interrogate.
To restore an ecosystem, it almost seems impossibly complex. For example, you have to provide habitat for an unfathomable abundance and diversity of various organisms/species/taxa. This is the nature we want to bring back and support. Not only is that difficult, but humans have to decide what type of ecosystem we should restore - or rather aim to restore and also deem feasible to restore. Wetlands, grasslands, woodlands, forests? Possibly multiple. Further, ecosystems are dynamic and changing, as species interact with one another and with their environment. How can we even begin to 'build' or 'construct' all this?
Anyway, there is so much - too much - to write about in this topic.
So I am just going to write about the revegetation that has been done at Yalukit Willam Nature Reserve. Maybe also write about how revegetation relates to habitat.
I have visited this reserve three times over the past year and can show how the vegetation has grown. The dates were:
- 27/8/25 (early spring)
- 3/4/26 (autumn)
- 11/7/26 (winter)
Before and after photos
I always love seeing before and after images of revegetation works. It rewarding seeing how its all growing. I took a photo of the same log on each visit, that will soon be completely concealed by surrounding plants:
As seen in the photos Viminaria juncea aka Golden seaspray has grown immensely.
You are also able to observe how the reserve changes over the seasons. Some swales are full of water during winter and dry up over the summer. These seasonally inundated areas are home to some unique species too.
One of these unique species is Ranunculus amphitrichus aka the Small River Buttercup:
The species in Ranunculus are difficult to tell apart. Ranunculus papulensis is also local to the area, but is pretty rare, so leading me to go with R. amphitrichus.
There's plenty of lignum Duma florulenta too! Which is great to see. Small birds, like wrens and finches will be able to take refuge in here away from all those Noisy Miner bullies. This is gonna be hard to control, likely blocking a path or two in the future.
Another cool thing about this lignum: I believe the lignum found in this reserve is quite likely the only lignum in the inner SE suburbs of Melbourne. I reckon you could draw a 10km radius and not find another lignum (the next closest population possibly existing in Westgate Park).
Why do we revegetate?
At it's core there is this 'if you build it, they will come' philosophy. The whole premise of revegetation and the reason that we often focus on revegetation is the assumption that vegetation provides habitat. Re-establishing this physical structure, both above and below ground, they (the animal, and importantly even broader than that, the biological communities) will come. Basically, plants are the foundational trophic layer that supports above and below ground biodiversity of terrestrial ecosystems. Planting plants not only restores the plant communities1, but also the animals, fungi, protists, slime molds, bacteria communities, theoretically everything in that ecosystem?!
For example a seedling planted today may grow into a large tree. As the tree grows it will provide more habitat. More leaves for insect herbivores, more floral resources for pollinators, the dense foliage provides a home for possum (and their dreys), birds (and their nests). Eventually as the tree ages, hollows emerge, providing shelter for those hollow-dependent animals. Meanwhile at ground-level, the leaf litter supports ground beetles that burrow, increasing water infiltration into soils. Underground, root nodules may house nitrogen-fixing bacteria, improving soil nutrients...and so on.
Basically all this is to say that, as the tree grows, the tree can create suitable conditions for other species to co-exist. Collectively all these species make up the communities we observe. In this regard, trees are keystone structures, particularly in human modified landscapes as this paper argues.
Such an idea is bold. That planting vegetation will help drive ecosystem restoration now and into the the future. Even further, plants can be relied upon to do so. There is a very tangible certainty that comes with using plants. Animals may come and go, but established plants will remain2. They are manageable, somewhat predictable units of structure. This is important if there are certain desired outcomes for a nature reserve (which obviously humans have). So again plants are foundational in that we can rely on them for structure above and below ground.
The 'if you build, it they will come' philosophy is important to test as it underpins most revegetation efforts and requires substantial trust that natural succession will lead us to our desired endpoint. It also assumes that any restoration action (such as revegetation) will drive restoration success. The willingness by humans to hand over restoration responsibilities to nature, and its inherent unpredictibility, is in conflict with humans wanting to have control of restoration outcomes.
But I need to bring this back to the Yalukit Willam Nature Reserve, I knew I would go off on a tangent...
Evidence of an ecosystem being functional at Yalukit Willam Nature Reserve
Speaking of logs, I noticed one being decomposed by an orange fungi, probably Pycnoporus coccineus:
Just as the decomposers are decomposing, parasites are parasitising. In fact I found a black wattle Acacia mearnsii with not one, but two stem-parasites attached!
Each mistletoe attaches to a host tree (usually an Acacia, Allocasuarina or Eucalyptus sp. in Australia) and steals nutrients/water. Most mistletoes in Aus and still able to undertake photosynthesis normally, and hence are only partial parasites, or referred to as hemiparisites.
A great resource on Australian Mistletoes is here.
Next to a creek, a paper wasp nest is attached to a recently planted Juncus sp. (evidence supporting the 'if you build it, they will come' hypothesis):
When I step foot into a nature reserve, I like to see if the reserve is functional. That is, are species carrying out their roles in the ecosystem. Are there numerous species interactions? I try to find examples of this. Species interacting with their environment (such as fungi on a log) or species interactions with each other (such as mistletoe parasites) are so interesting to find.
In my opinion, it is also a way to judge if habitat has been made/constructed/restored. We want to discover examples that corroborate with this, 'if you build it, they will come' philosophy. Of course, having a greater diversity of species will provide more 'roles' (and redundancy) in the system. Biodiversity and ecosystem function are very much linked, not least as species interactions do require having two or more species3.
But biodiversity isn't everything... we also need bio-abundance if we want functional ecosystems. It is a perhaps lesser known term, but can help describe the magnitude of biological communities, and all the various ecosystem processes/services being undertaken. A nature reserve with 200 worms will function very differently to the same nature reserve with 2,000,000 worms.
A nice article by Dr Gareth Parry gives examples on how focusing on species richness alone can vastly underestimate the scale of loss in biological communities. The article also raises other related issues, like 'gardening' nature reserves, and is well worth a read.
In conclusion, this is how we can build a nature reserve. Revegetation aims to provide long-term habitat that can support biological communities. Meanwhile, the biodiversity and bioabundance contributes to the overall ecosystem functionality.
Anyway I have written enough.
Honestly, hands down, Yalukit Willam is one of the best ecosystem restoration projects I have seen. Still very early days yet, so I want to temper my praise. However I am excited to visit again in the future.