Most Australian capital cities have at least 80% chance of unusually warm and dry spring as climatologists watch developing system with increasing alarm
The El Niño climate phenomenon linked to record global temperatures and now locked in place in the Pacific Ocean could develop into the strongest on record, according to Australia’s Bureau of Meteorology.
Climatologists are watching the strengthening El Niño with increasing alarm, saying the forecasts from climate models in the coming months are “mind blowing” and “astounding”.
The spidery wattle is a rare but much-loved species in South Australia.Emily McAllan
The spidery wattle (Acacia araneosa) is a national treasure.
This plant is named for its spidery, leaf-like phyllodes and shares the same iconic golden flowers as Australia’s floral emblem, the golden wattle (Acacia pycnantha).
The spidery wattle is extremely rare, found only in a tiny area of South Australia’s Arkaroola Wilderness Sanctuary and Vulkathunha-Gammon Ranges National Park. This, alongside its unusual appearance, makes it a distinctive and beloved part of the landscape.
But this local icon is under threat. In the late 1830s, the first pastoral leases – which allowed livestock grazing on government land – were granted in South Australia. This significantly reshaped the state’s landscapes and ecosystems.
Our new study shows since that period, the spidery wattle population has drastically shrunk by about 98%. If this trend continues, the future of this unique species looks grim.
Thankfully, we can do something about it.
There are only two remaining spidery wattle populations, both found in South Australia.Emily McAllan
A perplexing plant
The spidery wattle has long puzzled scientists.
For years, researchers studying this unassuming plant noticed seed from the spidery wattle would sometimes “revert” to the form of another common wattle species, the silver wattle (Acacia rivalis). The silver wattle is a more widespread species than the spidery wattle, but grows in the same area.
This phenomenon could be explained by phenotypic plasticity — the ability of an organism to modify its physical traits or behaviour in response to environmental changes. This is fairly common in the plant world, with one example being Hydrangea flowers that change colour depending on soil pH levels.
These observations raised a crucial question: are spidery wattles just silver wattles that have changed form to suit local conditions?
It can be difficult to get funding for conservation efforts, so if we are to protect a plant or animal, it better be a “real” species!
Our latest research reveals, for the first time, the spidery wattle and silver wattle are indeed two distinct species. But we found these plants can hybridise in the wild, meaning the “reverted” seeds scientists observed were very likely hybrid seeds.
Why genes matter
We know of only two small spidery wattle populations, growing very close together on the hills of the Arkaroola Wilderness Sanctuary. Data from the mid-1990s suggests there were about 1,000 individual plants in total. This figure has almost certainly decreased since.
Despite being within shouting distance of each other, these two populations are genetically distinct. This is concerning because when populations shrink, they can rapidly lose genetic diversity. This is due to a process known as “genetic drift”, where the number of different genes in a small population randomly fluctuates.
Herbarium specimens collected for spidery wattle (left), potential hybrids (middle) and silver wattle (right), showing the differences between each.Brittany Hogben
It’s also more likely that individual plants with similar genes will interbreed. This means two small populations of 50 individuals are more vulnerable to pests, disease and environmental change, compared to a single population of 100.
This was the case with the Florida panther, a species once found across the south-eastern United States. In the 1980s, this panther population rapidly shrank, leading to inbreeding and the birth of many unhealthy kittens.
Worryingly, our research suggests the two remaining spidery wattle populations are already showing signs of being less genetically diverse.
A species under threat
Local observations suggest adult spidery wattles cope reasonably well in hot and dry conditions. However, their tiny seedlings are extremely vulnerable to drought and introduced herbivores such as rabbits, goats and sheep.
Over the past few millenia, Australia’s weather has become more dry and unpredictable. Our research shows these climatic changes have had a marked impact on the spidery wattle. This is because seedlings struggle to reach maturity in drought conditions, affecting the overall health of the spidery wattle population.
We found the species started declining roughly 3,300 years ago. Other research shows the now-extinct Tasmanian tiger disappeared from mainland Australia at this time, due to the same climatic changes.
However, the spidery wattle population started declining much faster once humans settled in South Australia and started farming from 1836 onwards. In the intervening years, the spidery wattle population has shrunk by roughly 98%.
So, what can we do?
Together, these factors mean the spidery wattle is now on the brink of extinction. However, work is already underway to ensure this unique species survives.
A passionate group of South Australian conservationists are spearheading efforts to set up exclusion fences, which stop herbivores from grazing spidery wattle seedlings. Through restoration planting, they have also grown and planted seedlings to boost the size of existing populations.
Importantly, about 2,000 spidery wattle seeds are being preserved in South Australia’s Botanic Gardens and the United Kingdom’s Millennium Seed Bank.
Currently, the spidery wattle is listed as a “Vulnerable” species federally, and “Endangered” at a state level. Given the two remaining populations are still at risk, it’s time we recognise it as a “Critically Endangered” species in Australia.
The spidery wattle should also be added to the International Union for Conservation of Nature’s Red List. These listings would support conservationists and policymakers to secure the funding needed to protect this iconic species.
We dedicate this work to the memory of Martin O‘Leary of the South Australian Herbarium, whose contribution to this study was crucial. A leading plant taxonomist in South Australia, Martin brought warmth and enthusiasm to his work, with a particular kindness to students. We are grateful for the privilege of working with him.
Brittany Hogben receives funding from the Australian Research Council. She is affiliated with Adelaide University, as well as other not-for-profit and professional associations including the Biology Society of South Australia and Society for Wildlife Forensic Science.
Andrew Lowe receives funding from the Australian Research Council and other Australian government sources. This work was supported by a grant from the Threatened Species Initiative of BioPlatforms Australia. He is a board member of Landscape South Australia – Hills and Fleurieu.
During this work, Colette Blyth was affiliated with Adelaide University and the University of Natural Resources and Life Sciences, Vienna. Funding for this project is from the Threatened Species Initiative via Bioplatforms Australia.
James B. Dorey is affiliated with the University of Wollongong and Flinders University. He is also affiliated with other professional associations including the Australian Native Bee Association, Australian Entomological Society and Australian Ecological Society.
But the bill contains other, no less concerning changes. This includes the proposal of a new “economic opportunity” function for the Department of Conservation (DOC), requiring it to:
recognise the economic opportunities that arise from the use and development of land and other resources managed by the department, and to enable this use and development to the greatest extent practicable.
The reforms would also relegate the New Zealand Conservation Authority and regional conservation boards to mere advisory bodies and give the minister broad powers to make policies to deliver on the government’s development agenda.
We argue that reform of the conservation system in a settler-colonial country such as Aotearoa New Zealand raises inevitable questions about who gets to decide where and how conservation lands are protected, and whose values guide the process.
Values in conservation
Many New Zealanders share a deep connection to conservation lands. Public mobilisation in opposition to the conservation reform reflects widely held concerns that their next hike or hunt will be less than idyllic.
But this connection is underpinned by European conservation values, including the concept of “fortress conservation”. This model of conservation prioritises the preservation of pristine natural landscapes and native species, “protecting” them from people’s activities which are assumed to be inherently harmful.
Such “preservationist” approaches to conservation have also created protected areas by removing Indigenous peoples from their ancestral territories or by restricting customary resource use, sometimes through violent means.
Significant tracts of conservation land remain subject to unresolved legal claims by M?ori. Some iwi (tribes or first nations) and hap? (sub-tribes or kinship groups) have attempted to collaborate with DOC to practice their rangatiratanga (legal and political authority) and kaitiakitanga (caretaking or guardianship) over ancestral lands. Others have shown leadership in conservation institutions such as the New Zealand Conservation Authority and UNESCO.
Aotearoa leads in environmental governance
It is not without irony that New Zealand’s most progressive environmental governance models have emerged from Treaty settlements that interact with conservation lands. This includes the legal personhood granted to the Whanganui River, Te Urewera and Taranaki Mounga.
These models have captured global attention as a gold standard for environmental governance. They signal a different way to value nature, grounded in relatedness and reciprocity between people and natural features, in which the land provides food, employment and identity for people and they care for it in return.
Such models also open new spaces for iwi and hap? to govern ancestral landscapes according to their own legal systems and worldviews, and for local governments, community members and industry groups to reconsider their relationship with nature.
As such, they enable people to move beyond a binary approach of preserving pristine landscapes and developing everything else. Other countries have been inspired by legal innovations in Aotearoa to reevaluate their relationships to nature, including the United Kingdom’s Rights of Nature Bill which passed its second reading in parliament.
The proposed conservation reforms place further strain on the government’s already uneasy relationship with Treaty partners, with concerns it will infringe both settled and unsettled Treaty rights.
Although the bill would require some consultation with iwi and hap?, the final decision would rest with the same minister who wants to shift DOC’s functions away from conservation and towards development.
The government argued Aotearoa’s conservation regime needed to be “modernised”. This is uncontroversial. It is an argument the conservation sector and iwi and hap? have made for decades.
Until now, policymakers have struggled to reconcile the competing values attached to Aotearoa’s conservation estate, and the extent to which it should be preserved or developed.
The government should learn from what Aotearoa has done well in the past and take up this opportunity to design lasting and equitable conservation reforms that uphold the rights and values of people with interests in conservation lands.
Only then can we move towards a conservation system that reflects Aotearoa’s local context and the value of partnership embodied in Te Tiriti o Waitangi.
It is time to abandon a European-style “lock it or lose it” approach to conservation. Aotearoa’s nature is diverse, as are the human values attached to it.
A relational approach that reflects the complex entanglement of human connections and livelihoods with natural features offers greater potential to rally New Zealanders towards a more sustainable conservation system, for people and nature alike.
Elizabeth Macpherson is a Rutherford Discovery Fellow. She also practices as a barrister and has provided legal and policy advice to Indigenous peoples and governments.
David Jefferson has received funding from organisations such as the Borrin Foundation to conduct research on Indigenous environmental rights. He has worked with iwi-owned native plant nurseries in Aotearoa New Zealand and engages in consultation with First Nations organisations to provide advice on intellectual property protection. He is the Secretary of the Knowledge of Oceania Society.
