Narrator: Welcome to Heartland Journeys, and to Yarraweyah, a privately owned property north-east of the Stirling Range National Park. Yarraweyah has extensive natural and restored bushland areas that lie within a crucial stretch of Gondwana Link’s habitat restoration work, between the Fitzgerald River and Stirling Range National Parks. This area is known as the Fitz-Stirling.
Meet Dr Nic Dunlop, Coordinator of the Citizen Science Program at the Conservation Council of Western Australia. For decades, Nic has used his scientific knowledge to assist and run citizen science projects, mostly involving birds.
One of Nic’s key projects is testing the effectiveness of a bird monitoring method that can be used by citizen scientists to identify the ecological outcomes of restoration and revegetation plantings, as well as habitat management.
He begins by talking about the broader landscape in the Fitz-Stirling area, and some of the goals of ecological restoration.
This section of the Gondwana Link here, called the Fitz-Stirling section, is a grossly over cleared, very low productivity, low nutrient environment that has seen a very high proportion of its native vegetation removed or degraded by agricultural activities. And that has had consequences. It’s had consequences for salinity, it’s had consequences for biodiversity, it’s probably had consequences for rainfall and water in the landscape. It’s had consequences for soil condition, all those sorts of issues.
So what we’re trying to do now is imagine a landscape where some of that functionality is restored, and connectivity is restored across a region where we have made serious mistakes in terms of the way it should be utilised and managed. So we’re trying to imagine a system where farming can be more productive, but the biodiversity is reconnected across the landscape, that the resilience of plant and animal populations are improved.
Narrator: Over the years, especially since about 2004, Nic has witnessed a rapid evolution in the practice of ecological restoration.
What we’re finding now is that we’ve gone through several generations of approaches to restoration. We had the early landcare approach, which was often tree-planting; carbon sequestration in the early days, which was all tree planting, and then moving more into biodiverse revegetation for restoration purposes. And even that has been greatly changing in recent times as we’ve improved the technology.
A lot of earlier biodiverse restoration as well as having fewer plant species, tended to overstock with the seed, which meant you ended up with very dense, shrubby sorts of vegetation.
What’s happened over time, and particularly with the most recent restoration, is that we’ve moved from a small numbers of native plant species planted in quite widely spaced rows to systems now where there are quite a large number of plant species used in restoration. The seed mixes are matched for soil types, which greatly improves the chances of establishing vegetation and ecological processes. We’re getting away from putting things in rows. We’re trying to build in seeding processes that create patches as well as clumps so you get a more natural, heterogeneous type of plant cover. And by using a lot more species we also get, a lot more strata or layers in the vegetation. All those things are important components of habitat and structure.
You can plant trees or establish vegetation and that’s self-evident in terms of what you see as a result. But what that’s not telling you is whether or not what you’ve done is actually leading to the restoration of ecological processes. Things like nutrient cycling, pollination, seed dispersal, and providing habitat for a whole range of animals. So if you actually want to understand process in developing ecosystems, you don’t look at the plants, but you look at the animals, because the animals are the things that are dependent on those processes.
Then the next question is, well what animals is it efficient to utilise as indicators of ecosystem change? And we could use almost any animal group, but if we want to do this in a context of community-based conservation, we have to do things that are going to be sufficiently effective, but also low cost. And one of the advantages of birds over mammals or reptiles or some invertebrate groups is that there are many more people who are capable of working and identifying birds than are capable of working with a lot of these other animal groups. So, we’ve evolved this process of using bird community and bird community structure as a basis for understanding ecosystem processes developing in these restored ecosystems.
In a fragmented landscape, because they have the advantage of being able to fly, birds can tell us about the condition of an isolated patch of vegetation better than something that can’t get there. You know, a pygmy possum can’t travel many kilometres across nothing but open paddock, whereas most birds have no real issues with colonising new places, if those places are suitable for them to utilise. So, it’s another good reason for choosing them as an indicator rather than something else.
Narrator: Nic was interviewed at Yarraweyah, where a group of citizen scientists were monitoring bird populations in a high quality restoration site. He begins by describing the results of a wider survey of bird communities in the Fitz-Stirling area of Gondwana Link that took place in 2017.
In this part of the Gondwana Link we did a snapshot survey of bird communities in restoration treatments ranging in age from the earliest back in 2004, right through to the restoration that was done in 2014. And we expected that you would see a transition where the older and more established the restoration was the more you would see in terms of ecosystem development as indicated by the bird community structure. But that’s not what we found. What we found was that some of the most recent restoration had got to a higher state of ecosystem development very quickly compared to older sites, some of which were now lagging well behind recent restoration. So restoration that was done, fourteen years ago, has either not developed a whole lot of habitat and process characteristics, or it’s done so much more slowly. So, we can now see in the modern restoration that the bird community structure is emulating that of our reference sites in the natural bush in only five or six years. Whereas many of the early sites had never got there over fourteen or more years, and some of them may actually need to be revisited, because they’re not going anywhere.
As you can imagine, if you have many more species of plants and much more diversity in terms of height structure, and much more diversity in terms of horizontal structure, or patchiness, then you have a lot more niches for different birds that occupy different habitats and use different resources.
Even though within 5 or 6 years modern biodiverse restoration it doesn’t look particularly like remnant vegetation the evidence from our bird work is that functionally, as far as the pool of bird species that are available in this region, it is equivalent to undisturbed vegetation.
This area we have here at Yarraweyah is a very recent site, if you look at what the birds are telling us, it’s only a year or two away, if it stays on the trajectory that other sites have followed, that it will actually have a bird community that resembles remnant vegetation in this region, which is really quite exciting.
This is sort of information that the monitoring animals can tell us. So what that really means: if you’re seeing the development of ecosystem process, then you’ll have a much higher chance that the system you develop is actually going to persist in the long term.
Narrator: Nic sees the need for some fine-tuning of planted areas to provide opportunities for other animals to move into a restored area to help with the restoration of ecosystem processes.
One of the things with early-stage restoration is that all the vegetation is young, so you don’t have woody material of high and large diameter. So you don’t have hollow logs, or big piles of leaf litter and things like that. So so one of the things that’s likely to be missing early on are places for things that nest in hollows to hang out. And if that’s the case, then they have to move through and they can’t hang around in your habitat. Now, something like a pygmy possum is probably quite important for things like eucalypt pollination. So it would be great to have them here. So sometimes you can speed that process up by providing artificial hollows until such time as the natural system develops them itself.
The other group, which is probably quite important and useful in restoration, of course, are insectivorous bats and the same thing can be done by putting up bat boxes inside restoration to bring them in. Things like that are quite important, for example, early stages of regulating the numbers of insects. What we don’t want to see is plagues of grazing insects, for example, defoliating our vegetation and if you’ve got some animal groups that are missing, then then that’s more likely to occur. This is a way of circumventing nature and speeding the process up a little bit.
Most of the vegetation in these young systems has already flowered and fruited a couple of times even in in five or six years, and things like pygmy possums associated with Eucalypts, particularly mallee Eucalypts, feed on both the nectar and the insects associated with the flowers. So it rapidly becomes habitat for things like that. And also in some situations for the honey possums, which are the nectivorous mammals that are endemic to the southwestern WA. I think the honey possums, which are the nectivorous mammals that are endemic to the southwestern WA, are more likely to be moving through these habitats rather than permanently here because you’re still lacking to some extent, a lot of the plants that they depend on. They’re mainly in the banksia family that are difficult to establish from direct seeding methods and often have to be introduced by the much harder business of trying to grow plants from tube stock, which is not easy.
Narrator: There are many benefits of restoration, particularly for threatened species and less common species like malleefowl. Nic mentions two properties here: Monjebup and Chingarrup, which are to the north-east and east of the Stirling Range National Park. Both are in the Fitz-Stirling area.
So whilst restoration in terms of animals is not usually targeted at threatened species it nevertheless, because it has that effect of increasing the resilience in the landscape, it will have a benefit for any threatened species that may be part of that system. One of the interesting things we’ve noted about the restoration is that some of the species which are not widely distributed and are regional endemics, the Western Whipbird is a classic example – absolutely loves, restoration, or at least modern restoration. I think the densities of Whipbirds in restoration are probably on average higher than they are in the remnant vegetation. And that’s probably also true of some other birds like Scrub Robins and also well used by Babblers, which are also species that are badly affected by fragmentation in agricultural landscapes. So, we’re quite surprised to see how quickly some of these birds, which are probably of higher significance, are actually utilising restoration.
One of the striking almost quite amusing things about the more recent restoration is that malleefowl love it. I think some critical elements of malleefowl habitat are vegetation with a strong barrier effect so you can’t see in, but also which contains spaces where the animals can build their nest mounds.
So at Monjebup and Chingarrup we are seeing malleefowl mounds popping up now with increasing frequency in the restoration areas. We were at Monjebup yesterday and every one of our study sites we went to we encountered malleefowl and we were quite a long distance from any remnant vegetation. So they seem to be able to utilise these restored habitats and perhaps live entirely in these restoration patches. So that’s one of our regional threatened species that seems to be benefiting quite markedly from the restoration project.
One of the critical things about fragmented landscapes is you’ve got limited area left in remnant vegetation. And one of the key questions is, what role is the restoration playing in animal populations in that landscape? One of the roles that this sort of vegetation may now already be playing is providing extra habitat during critical periods where the climate conditions are not good, such as in a long drought. These systems because they’re younger, have much faster growth, higher regenerating biomass, are more productive than the actual bush itself. So there’s a lot more insects and other things available in this habitat than in the remnant vegetation, and that means that a lot of bird populations, for example, might be able to maintain much higher populations now than they would have been in the past, which ultimately will improve the chances of those populations surviving in the landscape, particularly in a context where climate change may put more and more pressure on those ecosystems.
Narrator: This has been a Gondwana Link production with story development by Nicole Hodgson, Margaret Robertson and Keith Bradby, narration by Nicole Hodgson, and music by Rod Vervest. Our warm thanks to Nic Dunlop, to audio editor Teresa Ashton-Graham and audio producer Kim Lofts of Blue Manna Studio. Thanks also to Frank Rijavec and Margaret Robertson for the original 2018 recording.