What are native grasslands, and why do they matter?



The Southern Tablelands contain rare native grasslands.
Tim J Keegan/Flickr, CC BY-SA

Mike Letnic, UNSW

Coalition minister Angus Taylor is under scrutiny for possibly intervening in the clearing of grasslands in the southern highlands of New South Wales. Leaving aside the political dimensions, it’s worth asking: why do these grasslands matter?




Read more:
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The grasslands in much of eastern Australia are the result of forests and woodlands cleared to “improve” the landscape (from a grazier’s point of view) to make it suitable for grazing livestock.

The “improvment” typically entails cutting trees, burning the felled timber and uprooting tree stumps, followed by ploughing, fertilising and sowing introduced grasses that are more palatable to livestock than many native grasses.

However, largely treeless native grasslands once occurred at high elevations across much of the Monaro tableland, in the area stretching between Canberra and Bombala.

The Monaro grasslands (or in scientific speak, the natural temperate grassland of the Southern Tablelands) are in relatively dry and cold areas, particularly in upland valleys or frost hollows where cold air descends at night.

The combination of dry climate and cold restricts tree growth and instead has encouraged grasses and herbs. Native grasses such as kangaroo grass and poa tussock dominate the grasslands, but there are many other unique plants. A typical undisturbed grassland area will support 10-20 species of native grasses and 40 or more non-grass species.




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The grassy plains are also home to unique cold-adapted reptiles such as the grass-land earless dragon, little whip snake, pink-tailed worm lizard and striped legless lizards. This combination of plants and animals create a unique ecological community.

Striped legless lizards may resemble a snake, but most of its body is actually tail. It has vestigial limbs and a non-forked tongue.
Benjamint444/Wikipedia, CC BY-NC-SA

A fraction remain

It is estimated only 0.5% of the area that would once have been natural temperate grasslands in the Southern Tablelands remains. The rest has been gradually “improved” since the mid-nineteenth century to make them more productive for livestock grazing.

Livestock dramatically change the composition of grasslands, as animals remove palatable plants and compact the soil under their weight. Disturbed soil and the livestock also help to spread non-native weeds.

However, most native grasslands have not just been modified by grazing but completely replaced by man-made pastures. That is, the land has been ploughed, fertilised and the seeds of introduced grasses have been planted.




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These changes to the landscape mean much of the landscape is dominated by introduced plants and is now unsuitable for many of the native plants and animals that once lived and grew there.

Because the Natural Temperate Grassland of the Southern Tablelands is now so rare it is classified as critically endangered and federally protected. Furthermore, many of the distinct plants and animals that still live in these grasslands are classified as vulnerable or endangered.

The pink-tailed worm lizard is one of the rare species living in the native grasslands of the Southern Tablelands.
Matt Clancy/Wikimedia Commons, CC BY-SA

Some of the best remaining examples of the Monaro grasslands can be found in old cemeteries and in areas set aside as public livestock grazing areas. These areas of public land have often been spared from pasture improvement or only lightly grazed, and thus now support relatively intact native grassland ecosystems.




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While, to the untrained eye the Monaro grasslands may seem unremarkable and difficult to distinguish from grazing pastures, they are deeply important. They show us what Australia once looked like, and act as a haven for native biodiversity.

Indeed, what remains of the natural grasslands is now so disturbed by agriculture there is a real threat this distinctive ecological community and many of the species it contains may disappear altogether, if they are not protected from excessive grazing, fertilisers and the plough.The Conversation

Mike Letnic, Professor, Centre for Ecosystem Science, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Cross-pollination, migration, adaptation: Australia’s fragile grasslands at the Venice Biennale



File 20180529 80658 2k4c8r.jpg?ixlib=rb 1.1
Ten thousand native grassland plants were grown in Italy for Australia’s national pavilion at the Biennale.
Dane Voorderhake

William Feuerman, University of Technology Sydney

Review: Venice Biennale (Architecture)


The 16th International Architecture Exhibition, the Venice Biennale, is now open. With 62 countries represented, the Biennale is a demonstration of “how the world might be perceived differently from diverse parts of our planet,” as described by the event curators.

This year’s theme, Freespace, is about the potential of architecture to be perceived beyond face value. With a somewhat romantic undertone, the curatorial statement emphasises the physical building. This is in clear contrast to the 15th Biennale in 2016, curated by Chilean architect Alejandro Aravena, which foregrounded social and political issues.

There are 62 national pavilions mostly in or around the Giardini, Venice’s parkland. The pavilions, with curators selected from each respective country, provide great insight into the current state of the architecture profession.

Repair, Australia’s Pavilion, curated by Baracco+Wright Architects in collaboration with artist Linda Tegg, constructs an immersive sensory experience for visitors. Repair aims to reclaim endangered grasslands that existed pre-European settlement.
More than 10,000 plants, including 65 different Victorian grassland species, fill a black cube designed by Denton Corker Marshall architects.

Only 1% of these grasslands remain in Victoria. The Australian curators explained that the reclamation of grasslands is “a sort of reverse order of urban sprawl”.

Projections in Australia’s national pavilion show other buildings that have incorporated nature.
Dane Voorderhake



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The plants are arranged in sporadic densities throughout the space. I yearned for the room to be filled even more as the smells, which are ever present, brought a familiarity to a foreign place. Artificial lights above illuminate and protect the interior landscape. Every so often the lights dim and two perpendicular walls project videos of 15 Australian architecture projects that address the environmental issues posed by the curators.

At face value, the pavilion can be seen purely as a comment on the environment, but more important is the process the curators took to construct the exhibition. The 10,000 Australian plants were “lovingly nurtured from seedlings to maturity in Sanremo, Italy”.

Like Australian gum trees that have made their home in California, these Victorian grasslands in Venice represent a successful model of migration and adaptation, just as the ritual of this Biennale represents at best, moments of productive displacement and cross-pollination.

Switzerland’s national pavilion, winner of the Biennale’s Golden Lion.
Dane Voorderhake

Still, the grasslands pavilion left open the question of what would happen to these exiles after the Biennale. Would they be returned home, and at what cost? In our era of mass migration and high carbon footprint transport and agriculture, I wondered what fate would be most fitting.

This year’s Golden Lion Winner, the top award at the Biennale, was awarded to Switzerland for House Tour. In perfect Swiss style, the exhibition creates domestic spaces at multiple scales using materials and fittings commonly used in new-build housing or rented apartments. Curated by Alessandro Bosshard, Li Tavor, Matthew van der Ploeg and Ani Vihervaara, the exhibition aims to question the acceptance of banality.

The British Pavilion, Island, constructs a scaffold around an existing building, providing access to the upper roof structure where the 1909 building pokes out at the centre of the terrace, a literal island. Inside, the pavilion remains empty, void of an exhibition. As the British curators, Adam Caruso, Peter St John and Marcus Taylor, describe

The state of the building suggests many themes; including abandonment, reconstruction, sanctuary, Brexit, isolation, colonialism and climate change. It is intended as a platform, in this case also literally, for a new and optimistic beginning.

The British pavilion constructed a scaffold around an existing building.
Dane Voorderhake

At the entry to the Arsenale, the centrepiece of the Biennale located in a 13th century Venetian shipyard, curators Yvonne Farrell and Shelley McNamara have hung what feels like hundreds of strands of rope. Here begins the showcase of 71 architects from around the world, each responding to the event’s theme.

The space is filled with a beautiful, yet erratic, set of architectural models, full-scale constructions and interactive media. The Central Pavilion, the Biennale’s other major venue, has a similar sprinkling of work.

The entrance of the Arsenale at the Venice Biennale.
Dane Voorderhake

The 71 participants have each built an object of delight, transforming the 200m hall into a street scene with a series of micro buildings along its sides.

Australian architect John Wardle’s popular installation, Somewhere Other, is an optical machine, or as the placard describes, “a portal, an elaborate window, a calibrated device, a long lens between Venice and Australia”. Australia is also represented by Tasmanian architects Room 11.

Somewhere Else designed by John Wardle.
Dane Voorderhake

Somewhere Other is a beautifully made native timber object generating a range of experiences for its users. It is poetic in both description and construction, a striking demonstration of Wardle’s work and a strong representation of a continent about as far from Venice as you can get.

Other highlights include the a model of the Fuji kindergarten designed by Japanese firm Tezuka Architects. Projected drone footage shows children running free around the school’s circular roof.

Tezuka Architects’ kindergarten with projections of children.
Dane Voorderhake

Ricccardo Blummer and team’s Automatiche E Altri Esercizi (Italy), is “a walkable machine that continually builds minimal surfaces, composed of water and soap which only the reflection of light makes visible”.

Other projects to note were PROP/GLOBAL’s (Portugal) interactive media projected onto a curtain of fine grain tassels that form an enclosure; Valero Olgiati’s (Switzerland) intervention of 33 white slender cylindrical columns producing what he describes as “an intensified spatial experience”; and Kazuya Sejima and Ryue Nishizawa’s (Japan) acrylic, almost invisible, layered circular space.

Despite the beauty and poetry of many of the works aligning the Arsenale, one cannot deny their indulgence. In 2016, curator Alejandro Aravena asked if exhibitions would widen their scope beyond cultural and artistic dimensions to social, political, economic and environmental ideas. It’s not clear to me that many of the exhibitors at the current Biennale have done this.


The ConversationThe Venice Biennale is on until November 25 2018.

William Feuerman, Senior Lecturer, School of Architecture, University of Technology Sydney

This article was originally published on The Conversation. Read the original article.

Tiny desert mice could help save Australia’s grasslands from invasion


Christopher Edward Gordon, University of Wollongong and Mike Letnic, UNSW Australia

You should stop skylarking about with those bloody desert mice and try and stop those woody weeds. I could see clear through that paddock in the ‘60s. Now look at it. That scrub costs us tens of thousands of dollars in lost fodder and it’s almost impossible to muster the livestock.

That blunt assessment of our research, first offered by a local farmer in Australia’s arid rangelands almost seven years ago, raised an irresistible question for us as field ecologists. Why are Australia’s (and many others around the world) grasslands becoming woodier?

It certainly was a question worth asking. Shrub encroachment – an increase in the cover of woody shrubs in areas once dominated by grasses – is not just an issue in Australia.

In two recent papers published in the journals Ecography and the Journal of Animal Ecology, we looked at one key reason why trees are invading grasslands, and how we could stop them. And it all comes down to tiny desert mice.

Shrub invasion

“Invasive native vegetation”, as bureaucrats call it, is a major problem for livestock producers in drylands throughout the world. This is because the shrubs compete for space and light with the grasses needed to feed their cattle and sheep.

Shrub encroachment ‘inside’ the Dingo Fence.
Dr Ben Moore

It is a hard problem to tackle. Clearing and fire are the most common methods of controlling woody shrubs. But these methods are laborious and often hard to implement on large scales.

Removing shrubs is also contentious because these are typically native species that provide important habitat for wildlife. The New South Wales parliament’s controversial relaxation in November of regulations governing vegetation clearing were designed partly to allow farmers to remove invasive native vegetation.

What’s going on?

The causes for the spread are complex and poorly understood. Shrub encroachment is often attributed to overgrazing by livestock, which favours the growth of shrubs over grasses. It has also been linked to a reduction in bushfires that wipe out the shrubs and an increase in atmospheric carbon dioxide, which can promote their growth.

However, we suspected another important factor could be at play. And it was those little desert mice that provided us with a big clue – and a possible solution.

Since European settlement, livestock grazing and the introduction of foxes, feral cats and rabbits have decimated Australia’s native mammals, especially in arid and semi-arid areas.

The bilbies, bettongs, native rodents and other small mammals that became rare or extinct across much of the continent in the early 20th century once played essential roles in Australian ecosystems, by shifting vast amounts of soil and consuming vegetation and seeds.

Historical accounts suggest that shrub encroachment quickly followed European settlement and mammal extinctions in many areas. This coincidence led us to ask: could the loss of native mammals be making Australia’s drylands woodier?

Hopping to it

To answer this question, we went to the northwest corner of NSW. Here the Dingo Fence marks the border with Queensland and South Australia.

The Dingo Fence.
Ben Moore

We wanted to know whether the local extinction of a native mammal, the dusky hopping mouse, which eats shrub seeds and seedlings, would allow more shrubs to grow. The Dingo Fence was the perfect study site because dusky hopping mice are common on the northwest side, “outside” the fence, where dingoes are present.

Dingoes keep fox numbers down, which are the mouse’s major predator. However, dusky hopping mice are rare on the “inside” of the fence (the NSW side), where dingoes are less common and foxes roam.

We first used historical aerial photographs to show that shrub cover was consistently higher inside the dingo fence (rodents rare) than outside (rodents common). We then did field surveys, which showed that the numbers of shrubs, their seedlings and their seeds were greater where rodents were rare.

We also showed that dusky hopping mice were major consumers of shrub seeds and capable of keeping the numbers of shrub seeds in the soil down.

Fieldwork in the Strzelecki Desert.
Dr Ben Moore

Going wild again

These results are exciting because they suggest that the loss of native mammals such as the dusky hopping mouse may be an important and overlooked driver of shrub encroachment, not only in arid Australia but also globally.

Perhaps more exciting, however, is how we can apply our work. Our research suggests that “rewilding” drylands by re-establishing rodents and other native mammal species that eat shrub seeds and seedlings, such as bettongs and bilbies, could curb the shrub invasion.

Although an abstract and even controversial idea, rewilding of native mammals would provide a long-term solution to a problem that has affected pastoralists for more than a century.

Further, it would represent a natural and cost-effective strategy with enormous benefits for the conservation of imperilled native mammals.

Before we can do so, we have to control foxes and feral cats across vast areas, which is no small feat. However, the economic and conservation potential make it an approach that is well worth taking seriously.

The Conversation

Christopher Edward Gordon, Associate Research Fellow, University of Wollongong and Mike Letnic, Associate Professor, School of Biological, Earth and Environmental Sciences, UNSW Australia

This article was originally published on The Conversation. Read the original article.