‘Existential threat to our survival’: see the 19 Australian ecosystems already collapsing

Dana M Bergstrom, University of Wollongong; Euan Ritchie, Deakin University; Lesley Hughes, Macquarie University, and Michael Depledge, University of Exeter

In 1992, 1,700 scientists warned that human beings and the natural world were “on a collision course”. Seventeen years later, scientists described planetary boundaries within which humans and other life could have a “safe space to operate”. These are environmental thresholds, such as the amount of carbon dioxide in the atmosphere and changes in land use.

Crossing such boundaries was considered a risk that would cause environmental changes so profound, they genuinely posed an existential threat to humanity.

This grave reality is what our major research paper, published today, confronts.

In what may be the most comprehensive evaluation of the environmental state of play in Australia, we show major and iconic ecosystems are collapsing across the continent and into Antarctica. These systems sustain life, and evidence of their demise shows we’re exceeding planetary boundaries.

We found 19 Australian ecosystems met our criteria to be classified as “collapsing”. This includes the arid interior, savannas and mangroves of northern Australia, the Great Barrier Reef, Shark Bay, southern Australia’s kelp and alpine ash forests, tundra on Macquarie Island, and moss beds in Antarctica.

We define collapse as the state where ecosystems have changed in a substantial, negative way from their original state – such as species or habitat loss, or reduced vegetation or coral cover – and are unlikely to recover.

bleached coral — The Great Barrier Reef has suffered consecutive mass bleaching events, causing swathes of coral to die.
Shutterstock

The good and bad news

Ecosystems consist of living and non-living components, and their interactions. They work like a super-complex engine: when some components are removed or stop working, knock-on consequences can lead to system failure.

Our study is based on measured data and observations, not modelling or predictions for the future. Encouragingly, not all ecosystems we examined have collapsed across their entire range. We still have, for instance, some intact reefs on the Great Barrier Reef, especially in deeper waters. And northern Australia has some of the most intact and least-modified stretches of savanna woodlands on Earth.

Still, collapses are happening, including in regions critical for growing food. This includes the Murray-Darling Basin, which covers around 14% of Australia’s landmass. Its rivers and other freshwater systems support more than 30% of Australia’s food production.

The effects of floods, fires, heatwaves and storms do not stop at farm gates; they’re felt equally in agricultural areas and natural ecosystems. We shouldn’t forget how towns ran out of drinking water during the recent drought.

Drinking water is also at risk when ecosystems collapse in our water catchments. In Victoria, for example, the degradation of giant Mountain Ash forests greatly reduces the amount of water flowing through the Thompson catchment, threatening nearly five million people’s drinking water in Melbourne.

This is a dire wake-up call — not just a warning. Put bluntly, current changes across the continent, and their potential outcomes, pose an existential threat to our survival, and other life we share environments with.

A burnt pencil pine, one of the world’s oldest species. These ‘living fossils’ in Tasmania’s World Heritage Area are unlikely to recover after fire.
Aimee Bliss, Author provided

In investigating patterns of collapse, we found most ecosystems experience multiple, concurrent pressures from both global climate change and regional human impacts (such as land clearing). Pressures are often additive and extreme.

Take the last 11 years in Western Australia as an example.

In the summer of 2010 and 2011, a heatwave spanning more than 300,000 square kilometres ravaged both marine and land ecosystems. The extreme heat devastated forests and woodlands, kelp forests, seagrass meadows and coral reefs. This catastrophe was followed by two cyclones.

A record-breaking, marine heatwave in late 2019 dealt a further blow. And another marine heatwave is predicted for this April.

These 19 ecosystems are collapsing: read about each

What to do about it?

Our brains trust comprises 38 experts from 21 universities, CSIRO and the federal Department of Agriculture Water and Environment. Beyond quantifying and reporting more doom and gloom, we asked the question: what can be done?

We devised a simple but tractable scheme called the 3As:

Awareness of what is important
Anticipation of what is coming down the line
Action to stop the pressures or deal with impacts.

In our paper, we identify positive actions to help protect or restore ecosystems. Many are already happening. In some cases, ecosystems might be better left to recover by themselves, such as coral after a cyclone.

In other cases, active human intervention will be required – for example, placing artificial nesting boxes for Carnaby’s black cockatoos in areas where old trees have been removed.

Two black cockatoos on a tree branch — Artificial nesting boxes for birds such as the Carnaby’s black cockatoo are important interventions.
Shutterstock

“Future-ready” actions are also vital. This includes reinstating cultural burning practices, which have multiple values and benefits for Aboriginal communities and can help minimise the risk and strength of bushfires.

It might also include replanting banks along the Murray River with species better suited to warmer conditions.

Some actions may be small and localised, but have substantial positive benefits.

For example, billions of migrating Bogong moths, the main summer food for critically endangered mountain pygmy possums, have not arrived in their typical numbers in Australian alpine regions in recent years. This was further exacerbated by the 2019-20 fires. Brilliantly, Zoos Victoria anticipated this pressure and developed supplementary food — Bogong bikkies.

Other more challenging, global or large-scale actions must address the root cause of environmental threats, such as human population growth and per-capita consumption of environmental resources.

We must rapidly reduce greenhouse gas emissions to net-zero, remove or suppress invasive species such as feral cats and buffel grass, and stop widespread land clearing and other forms of habitat destruction.

Our lives depend on it

The multiple ecosystem collapses we have documented in Australia are a harbinger for environments globally.

The simplicity of the 3As is to show people can do something positive, either at the local level of a landcare group, or at the level of government departments and conservation agencies.

Our lives and those of our children, as well as our economies, societies and cultures, depend on it.

We simply cannot afford any further delay.

Dana M Bergstrom, Principal Research Scientist, University of Wollongong; Euan Ritchie, Professor in Wildlife Ecology and Conservation, Centre for Integrative Ecology, School of Life & Environmental Sciences, Deakin University; Lesley Hughes, Professor, Department of Biological Sciences, Macquarie University, and Michael Depledge, Professor and Chair, Environment and Human Health, University of Exeter

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

Phantom of the forest: after 100 years in hiding, I rediscovered the rare cloaked bee in Australia

James B. Dorey, Flinders University

It’s not often you get to cast your eyes on a creature feared to be long-gone.

Perhaps that’s why my recent rediscovery of the native bee species Pharohylaeus lactiferus is so exciting — especially after it spent a century eluding researchers.

But how did it stay out of sight for so long?

A creature overshadowed

Australia is home to 1654 named species of native bee. Unfortunately, these are often overshadowed in the eyes of public by the widespread and invasive European honeybee.

Scientific research on Australian native bees is lagging, compared to many other nations.

With this in mind, it may not be surprising to learn some native species can go unnoticed for many years. Although, when it’s the only representative of a whole genus, one might start to worry about losing something special.

In this case the genus is Pharohylaeus, where “pharo” means “cloaked”, as these bees’ first three abdominal segments overlay the others to resemble a cloak.

I found the cloaked bee P. lactiferus during a major east coast sampling effort of more than 225 unique sites. The discovery, and what I learnt from it, helped me find more specimens at two additional sites.

It also made me wonder why P. lactiferus had been missing for so long. Is it naturally rare, hard to find, or perhaps threatened?

Taxonomic trouble

Many Australian bees are very difficult to identify to a species level. In fact, some might be nearly impossible.

However, P. lactiferus is a relatively distinct black and white masked bee. Masked bees are those from the subfamily Hylaeinae, named so because they often have striking, bright facial patterns on an otherwise dark face.

With this distinctive appearance, identification issues weren’t a contributor to the mystery of P. lactiferus.

Seeing red

Still, despite having sampled extensively across sites and flowering plant species, I only found P. lactiferus on two types of plant: the firewheel tree and the Illawarra flame tree — both of which boast exuberant red flowers.

_Brachychiton acerifolius_ flowers. — The Illawarra flame tree (*Brachychiton acerifolius*).
James Dorey, Author provided

Bees generally don’t see shades of red, so such plants are usually pollinated by birds. It could be that bee researchers tend to avoid sampling these red flowering plant species for this reason.

Then again, bee vision and bee perception are not always the same. And bees are also guided by their keen sense of smell.

Habitat specialisation

So far, I’ve only found P. lactiferus within about 200 metres of one major vegetation subgroup, which is tropical or sub-tropical rainforest.

The first specimens I collected were in Atherton, Queensland. I later found more in Kuranda and Eungella. Some of these specimens are now stored in the South Australian Museum.

The habitat specialisation of P. lactiferus may suggest it has an above-average level of vulnerability to disturbances, particularly if it needs a strict set of requirements to make it through its entire life-cycle.

It is one of myriad bee species that nest in narrow, wooden hollows. Some bees such as Amphylaeus morosus dig these themselves and may require specific plant species to make their nest in.

Others such as Exoneurella tridentata need to use holes made by weevil larvae in two particular tree species: western myall and bullock bush.

Rainforests are also notoriously hard to sample. If a bee species spends much of its time in the high canopy, finding it would be difficult.

That said, two early collectors managed to find six specimens of P. lactiferus between 1900 and 1923. So its rarity doesn’t necessarily come down to it being a canopy-dweller.

Potential threats

We know in the bioregions where P. lactiferus has been found that rainforests have undergone both habitat destruction and fragmentation since European colonisation. This threat hasn’t abated and Queensland is still a land-clearing hotspot.

We also know these rainforests burnt across Queensland every year between 1988 and 2016. The 2019-20 black summer megafires burnt nearly double the area of any previous year.

For some bee species this may not be a problem. But for a species that potentially requires specific foods, habitats and even other species, it could mean local extinction.

Only so many populations of a single species can disappear, before there are none left.

Where does this leave us?

P. lactiferus persists, which is wonderful. Unfortunately, we can’t yet say whether or not it is threatened.

To determine this confidently would require a robust, extensive and targeted survey regime.

We may not be able to undertake such a regime for all 1654 of the named bee species in Australia. But perhaps we could make that effort for the country’s only cloaked bee.

James B. Dorey, PhD Candidate, Flinders University

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

Against the odds, South Australia is a renewable energy powerhouse. How on Earth did they do it?

Michael McGreevy, Flinders University and Fran Baum, Flinders University

Less than two decades ago, South Australia generated all its electricity from fossil fuels. Last year, renewables provided a whopping 60% of the state’s electricity supply. The remarkable progress came as national climate policy was gripped by paralysis – so how did it happen?

Our research set out to answer this question. We analysed policy documents and interviewed major actors in South Australia’s energy transition, to determine why it worked when so many others fail.

We found governments need enough political power to push through changes despite opposition from established fossil fuel interests. They must also watch the energy market closely to prevent and respond to major disruptions, such as a coal plant closing, and help displaced workers and their towns deal with the change.

South Australia shows how good public policy can enable dramatic emissions reduction, even in a privately owned electricity system. This provides important lessons for other governments in Australia and across the world.

Artist impression of SA solar plant — South Australia is a world leader in renewables deployment. Pictured: artist impression of solar thermal plant proposed for the state.
Solar Thermal Power Plant

Why is the energy transition so hard?

In decades past, fossil-fuel-dominated energy markets revolved around a few big, powerful players such as electricity generators and retailers. Overhauling such a system inevitably disrupts these incumbents and redistributes benefits, such as commercial returns, to newer entrants.

This can create powerful – and often vocal – losers, and lead to political problems for governments. The changes can also cause hardship for communities, which can be rallied to derail the transition.

The change is even harder in a privatised energy market, such as South Australia’s, where electricity generators and other players must stay profitable to survive. In the renewables shift, fossil fuel businesses can quickly become commercially unviable and close. This risks supply shortages, as well as price increases like those after Victoria’s Hazelwood coal plant closed in 2017.

The obstacles help explain why a wealthy nation such as Australia, with extremely high per capita emissions and cheap, plentiful renewable resources, has struggled to embrace its clean energy potential. Even frontrunners in environmental policy, such as Germany, have struggled to make the switch.

Coal workers and their communities must be assisted during the renewables transition.
Dan Himbrechts/AAP

How South Australia did it

South Australia is a dry state – extremely vulnerable to climate change – with abundant wind and solar resources. These factors gave it the motivation and means to transition to renewables.

The South Australian Labor government, elected in 2002, adopted a target for 26% renewables generation by 2020. At the time, wind energy was already a competitive supplier of new generation capacity in Europe, creating an established wind farm industry looking to invest.

Some of South Australia’s best onshore wind potential was located near transmission lines running 300 kilometres from Port Augusta to Adelaide. This greatly reduced the cost of connecting new wind generators to the grid.

South Australia benefited greatly from the federal renewable energy target, established by the Howard government in 2001 and expanded under the Rudd government.

The scheme meant the South Australian government didn’t need to offer its own incentives to meet its renewables target – it just had to be more attractive to private investors than other states. This was a relatively easy task. Under the state Labor government, South Australia’s energy and environment policy was consistent and coordinated, in contrast to the weak and inconsistent policies federally, and in other states.

To attract renewable energy investors, the government made laws to help construct wind farms in rural zones away from towns and homes. New wind farms were regularly underwritten by state government supply contracts.

As the transition progressed, the state’s largest coal generator, at Port Augusta, was wound back and eventually closed. To help workers and the town adjust, the state government supported employment alternatives, including a A$6 million grant towards a solar-powered greenhouse employing 220 people.

The Labor government enjoyed a long incumbency, and the state was not heavily reliant on the export of fossil fuels. This helped give it the political leverage to push through change in the face of opposition from vested interests.

Worker walks through greenhouse — A state government grant helped establish a solar greenhouse.
Sundrop Farms

It’s not easy being green

South Australia’s transition was not without controversy. Between 2014 and 2018, the state’s consumer electricity prices rose sharply. While critics sought to blame the increasing renewables share, it was largely due to other factors. These include South Australia’s continued reliance on expensive gas-fired power and the closure of the Hazelwood coal-fired power station in neighbouring Victoria, which fed large amounts of power into South Australia.

And in late 2016, South Australia suffered a statewide blackout. Again, renewables were blamed, when the disaster was in fact due to storm damage and overly sensitive trip switches.

After a second, smaller blackout six months later, the then federal treasurer Scott Morrison brought a lump of coal into parliament and argued South Australia’s renewables transition was:

…switching off jobs, switching off lights and switching off air conditioners and forcing Australian families to boil in the dark as a result of their Dark Ages policies.

In 2018, Labor lost office to a Liberal party highly critical of the renewables transition in opposition. But by then, the transition was well advanced. In our view, specific legislation would have been required to halt it.

The state Liberal government has now firmly embraced the renewables transition, setting a target for 100% renewable electricity by 2030. By 2050, the government says, renewables could generate 500% of the state’s energy needs, with the surplus exported nationally and internationally.

Scott Morrison, holding a lump of coal in Parliament, said SA’s renewables policy took the state back to the Dark Ages.
Lukas Coch/AAP

Leading the world

The South Australia experience shows a successful renewables transition requires that governments:

have enough political power to advance policies that disadvantage energy incumbents
monitor the energy market and respond proactively to disruptions
limit damage to displaced workers, businesses, consumers and communities.

It also highlights the importance of having transmission infrastructure near renewable resources before new generators are built.

As energy markets the world over grapple with making the clean energy transition, South Australia proves it can be done.

Michael McGreevy, Research Associate, Flinders University and Fran Baum, Matthew Flinders Distinguished Professor, Foundation Director, Southgate Institute for Health, Society & Equity, Flinders University

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

The dingo fence from space: satellite images show how these top predators alter the desert

The dingo fence in the Strzelecki Desert.
Mike Letnic

Adrian G. Fisher, UNSW; Charlotte Mills, UNSW; Mike Letnic, UNSW; Mitchell Lyons, and Will Cornwell, UNSW

As one of the longest structures in the world, the dingo fence is an icon of Australia. It stretches more than 5,600 kilometres across three states, including 150 kilometres that traverses the red sand dunes of the Strzelecki Desert.

Since it was established in the early 20th century, the fence has had one job: to keep dingoes out. The effect of this on the environment has been enormous — in fact, you can see it from outer space.

Our research has, for the first time, used satellite imagery to show the effects of predators on vegetation at a vast scale.

Dingoes eat kangaroos, and kangaroos eat grass. So on the side of the fence where dingoes are rare, there are more kangaroos, and less grass cover between sand dunes. This has important flow-on effects for the ecosystem in the region.

Similar changes to vegetation may have occurred throughout the world, where other large predators, such as wolves or big cats, have been removed. But these aren’t visible without the stark contrast boundaries like the dingo fence provide.

Reshaping the landscape

The fence was built to stop dingoes moving into sheep grazing land in southeastern Australia. As Australia’s largest terrestrial predator, dingoes pose a big threat to livestock.

Today, dingoes “inside” the fence continue to be killed by various means (not all of them humane), including poison baits, trapping and shooting.

Where dingoes are removed, increasing populations of kangaroos can lead to overgrazing.
Nick Chu

It has long been understood that removing large predators can drive changes in ecosystems across large areas. A well-known example is the removal of wolves in Yellowstone National Park in the 1920s, which saw an elk grazing increase, limiting the growth of tree and shrub seedlings.

Where dingoes are removed, increasing populations of kangaroos can lead to overgrazing. This, in turn, damages the quality of the soil, making the landscape more vulnerable to erosion.

Less vegetation can also leave small animals, such as the vulnerable dusky hopping mouse, exposed to other threats like cat predation. Indeed, 2019 research showed dingoes “outside” the fence keep cat and fox populations down in the Strzelecki Desert.

And research from 2018 showed dingo removal could even reshape the desert landscape, as changes to vegetation alter wind flow and sand movement.

Changes this large can’t be seen from the ground

Often, however, the effects of removing predators have gone unnoticed. There are two main reasons why.

First, many large predators were removed before scientists monitored ecosystems. For example, wolves were hunted to extinction in Britain during the 17th or 18th century (although there are now proposals to reintroduce them).

Second, changes occur over such large areas, so it’s difficult to spot any differences when researching from the ground.

So to gauge the impact of the fence, we used images captured by sensors on the NASA Landsat satellites, which have been regularly observing the Earth since 1972.

We looked at a section of the fence that follows the state border of New South Wales through the Strzelecki Desert, and used this to analyse the effects of removing a top predator.

32-year time lapse of dead vegetation cover for the Strzelecki Desert.

Capturing the impact

We used images processed for Australia by the Joint Remote Sensing Research Program, which are publicly available.

Using thousands of field measurements, each satellite image was converted into an image of “fractional cover”. This splits the landscape into three core components: bare soil, green vegetation and dead or dry vegetation.

The dead vegetation fraction, which includes all non-photosynthetic material such as dry leaves and twigs, is particularly useful in the desert. It’s a more reliable indicator of vegetation cover, as green vegetation only sticks around for three months or so after rain.

Viewing “natural colour” satellite images of the Strzelecki Desert, as our eyes see the world, doesn’t show the differences across the dingo fence very well. But when we view images of dead vegetation cover a few months after rainfall, we can see the stark effect kangaroo grazing has on the landscape, where dingoes are rare.

You can see these effects in the images below.

A natural colour Landsat image from winter in 2011 after a large rainfall event (left) does not show the dingo fence, though it does when converted to dead vegetation cover (right).
Adrian Fisher

When we analysed dead vegetation cover images for each season between 1988 and 2020, we found obvious differences between the maximum dead vegetation cover and the variability of dead vegetation cover through time, as the images below show.

The differences in vegetation cover across the dingo fence become most apparent after satellite images are converted to dead vegetation cover and analysed over time.
Adrian Fisher

The results from satellite images were supported by ground surveys. This included repeated nighttime counts of kangaroos and dingoes seen with powerful spotlights.

We also fenced off plots and observed how the vegetation changed. After five years, the kangaroo-free plots in the dingo-free areas looked like islands of grass in an otherwise bare desert.

One of the fenced plots excluding kangaroos in Sturt National Park, western NSW, showing a clear difference in vegetation cover due to grazing pressure where dingoes are rare.
Mike Letnic

What do we do about dingoes?

So, should we tear down the fence to reintroduce dingoes back into landscapes for the biodiversity benefits, like wolves in Yellowstone?

There are no simple answers to this question. Allowing dingoes to return to the landscape inside the fence will reduce kangaroo numbers and increase grass growth — but will also devastate sheep farming.

Conservationists, farmers and other land managers need to start discussing where and how we can safely return dingoes to landscapes, finding a balance between restoring ecosystems and protecting farms.

Adrian G. Fisher, Lecturer in Remote Sensing, UNSW; Charlotte Mills, Visiting Fellow, UNSW; Mike Letnic, Professor, Evolution and Ecology Research Centre, UNSW; Mitchell Lyons, Postdoctoral research fellow, UNSW, and Will Cornwell, Associate Professor in Ecology and Evolution, UNSW

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

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Environment, Wildlife and Wilderness – Articles and News

Daily Archives for March 7, 2021

‘Existential threat to our survival’: see the 19 Australian ecosystems already collapsing

The good and bad news

These 19 ecosystems are collapsing: read about each

What to do about it?

Our lives depend on it

Phantom of the forest: after 100 years in hiding, I rediscovered the rare cloaked bee in Australia

A creature overshadowed

Taxonomic trouble

Seeing red

Habitat specialisation

Potential threats

Where does this leave us?

Against the odds, South Australia is a renewable energy powerhouse. How on Earth did they do it?

Why is the energy transition so hard?

How South Australia did it

It’s not easy being green

Leading the world

The dingo fence from space: satellite images show how these top predators alter the desert

Reshaping the landscape

Changes this large can’t be seen from the ground

Capturing the impact

What do we do about dingoes?

The good and bad news

These 19 ecosystems are collapsing: read about each

What to do about it?

Our lives depend on it

Share this:

Like this:

A creature overshadowed

Taxonomic trouble

Seeing red

Habitat specialisation

Potential threats

Where does this leave us?

Share this:

Like this:

Why is the energy transition so hard?

How South Australia did it

It’s not easy being green

Leading the world

Share this:

Like this:

Reshaping the landscape

Changes this large can’t be seen from the ground

Capturing the impact

What do we do about dingoes?

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Like this: