How the size and shape of dried leaves can turn small flames into colossal bushfires


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Jamie Burton, University of Melbourne; Alexander Filkov, University of Melbourne, and Jane Cawson, University of Melbourne

The 2020-21 fire season is well underway, and we’ve watched in horror as places like K’gari (Fraser Island) burn uncontrollably, threatening people and their homes and devastating the environment.




Read more:
The K’gari-Fraser Island bushfire is causing catastrophic damage. What can we expect when it’s all over?


To lessen the impact of fires, we need to know when they are likely to burn and how intensely. Central to this is the flammability of litter beds — the layer of dead leaves, needles, twigs and bark on the forest floor.

Every large fire begins as a small fire, igniting and initially spreading through the litter bed, but what makes some litter beds more flammable than others?

Aerated litter beds fuel bigger fires

Over the past few years, fire scientists across the world have been busy tackling this burning question. In tropical forests in the Amazon, oak forests in North America and eucalypt woodlands in Australia, they have been collecting leaf litter beds and burning them in the laboratory to understand why litter beds from some plant species burn differently to others.

Each of these studies focused on leaf litter beds made up of a single species, and each identified a range of drivers of flammability. These drivers relate to both the characteristics of the individual litter particle (leaf, needle or branch) and the litter bed itself.




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Not all blackened landscapes are bad. We must learn to love the right kind


Our new research sought to consolidate these studies to find the common drivers of flammability between different single-species litter beds from different parts of the world.

From our meta-analysis, we found “litter packing” and “litter bulk density” were key factors in litter bed flammability.

Litter packing is a measure of how many gaps are between the dried leaves, needles and branches, and is important for determining how much air is available for burning. Likewise, litter bulk density is a measure of how much litter there is, and is important for determining how quickly and how long litter burns.

Oak tree litter bed
The litter bed from oak trees. The curly leaves create air gaps throughout the litter bed, which lead to bigger fires.
Jamie Burton, Author provided

We found loosely packed litter beds spread fire faster, burned for shorter periods of time and were more consumed by the flames. Importantly, we found this was universal across different types of litter beds.

We also identified the characteristics of leaves, needles and branches that cause variations in litter packing and litter bulk density.

For example, if the litter particles are “curly” and have a high surface area to volume ratio, then they’ll form litter beds with low packing ratios which burn faster and have higher consumption. Examples include leaves from some oak (Quercus) species.




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Tree ferns are older than dinosaurs. And that’s not even the most interesting thing about them


At the opposite end, small and less curly leaves form densely packed litter beds which are less aerated. Examples include coast tea tree (Leptospermum laevigatum) and conifers with small needles such as Larix and Picea. This results in slower moving fires, which do not consume all the litter.

For eucalypt litter beds, things are a little more complicated. Some species have thick and flat leaves which pack densely, so fire spreads more slowly and less litter is consumed. Other species, such as the southern blue gum (Eucalyptus globulus), have larger leaves which tend to pack less densely, so fires burn more quickly with taller flames.

Eucalyptus litter bed
The litter bed of eucalyptus trees.
Jamie Burton, Author provided

How can this information help us manage fires?

Of course, under extreme fire weather conditions, any litter bed will burn. However, at the beginning of a fire or under mild conditions, differences in litter characteristics may strongly influence how that fire spreads. Research on this can be useful for many aspects of fire management and planning.

For example, if we know which plants produce less flammable litter, we can select them for planting around houses, landscaping in fire-prone areas and also use them as green firebreaks to reduce the risk to people and homes. If a fire was to start, it may spread less quickly and be less intense, making it easier to contain and put out.

_Allocasuarina_ needle litter
Allocasuarina species with long thin needles tend to pack loosely, leading to faster flame spread and shorter burning times.
Jamie Burton, Author provided

But also it may not be that straightforward. When deciding which species to plant, the flammability of living plants needs to be considered, as well. Some plants that have less flammable litter may actually be highly flammable as a living plant. For example, although coast tea tree may form densely packed litter beds, the high oil content in the leaves makes it highly flammable as a living plant.

Our findings could also be used for predicting fire behaviour. For example, our results could be integrated into fire behaviour models, such as the Forest Flammability Model, which uses information on the composition and structure of the plant community to predict fire behaviour.

Next steps

Our study provides information on what leaf and litter characteristics affect flammability in litter beds composed of a single species. But in many forests, litter beds are made up of a variety of plant species, and more research is needed to understand what happens to litter packing and flammability in these multi-species litter beds.

Sydney red gum
The bark of the Sydney red gum tends to take longer to ignite, but burns for longer than its leaves.
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Besides different species, litter beds also contain different components such as twigs and bark. For example, in a mature wet eucalypt forest, bark and twigs can make up to 44% of the litter bed.

And for some eucalypt species, we already know bark burns differently to leaves. For example, the flaky bark of the Sydney red gum (Angophora costata) tends to take longer to ignite, but burns for a longer time compared to its leaves.

With fires becoming more frequent and fire seasons becoming longer, research into litter bed flammability has never been more needed.




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The Conversation


Jamie Burton, PhD Candidate, University of Melbourne; Alexander Filkov, Senior research fellow, University of Melbourne, and Jane Cawson, Research Fellow in Bushfire Behaviour and Management, University of Melbourne

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

Australia-first research reveals staggering loss of threatened plants over 20 years


Ayesha Tulloch, University of Sydney; Elisa Bayraktarov, The University of Queensland; Hugh Possingham, The University of Queensland; Jaana Dielenberg, Charles Darwin University; Jennifer Silcock, The University of Queensland; Micha Victoria Jackson, The University of Queensland, and Nathalie Butt, The University of Queensland

When it comes to threatened species, charismatic animals usually get the most attention. But many of Australia’s plants are also in grave danger of extinction, and in many cases, the problem is getting worse.

New Australia-first research shows the population sizes of our threatened plants fell by almost three-quarters, on average, between 1995 and 2017. The findings were drawn from Australia’s 2020 Threatened Species Index, which combines data from almost 600 sites.

Plants are part of what makes us and our landscapes unique. They are important in their own right, but also act as habitat for other species and play critical roles in the broader ecosystem.

This massive data-crunching exercise shows that a lot more effort is needed if we want to prevent plant extinctions.

Plants, such as WA’s Endangered Foote’s grevillea, make our landscape unique.
Andrew Crawford / WA Department of Biodiversity Conservation and Attractions

Spotlight on plants

Australia’s plant species are special – 84% are found nowhere else in the world. The index shows that over about 20 years up to 2017, Australia’s threatened plant populations declined by 72%. This is faster than mammals (which declined by about a third), and birds (which declined by about half). Populations of trees, shrubs, herbs and orchids all suffered roughly similar average declines (65-75%) over the two decades.

Of the 112 species in the index, 68% are critically endangered or endangered and at risk of extinction if left unmanaged. Some 37 plant species have gone extinct since records began, though many others are likely to have been lost before scientists even knew they existed. Land clearing, changed fire regimes, grazing by livestock and feral animals, plant diseases, weeds and climate change are common causes of decline.




Read more:
Undocumented plant extinctions are a big problem in Australia – here’s why they go unnoticed


Vulnerable plant populations reduced to small areas can also face unique threats. For example, by the early 2000s Foote’s grevillea (Grevillea calliantha) had dwindled to just 27 wild plants on road reserves. Road maintenance activities such as mowing and weed spraying became a major threat to its survival. For other species, like the button wrinklewort, small populations can lead to inbreeding and a lack of genetic diversity.

Fire, interrupted

Threatened plant conservation in fire-prone landscapes is challenging if a species’ relationship with fire is not known. Many Australian plant species require particular intensities or frequencies of burns for seed to be released or germinate. But since European settlement, fire patterns have been interrupted, causing many plant populations to decline.

Three threatened native pomaderris shrubs on the NSW South Coast are a case in point. Each of them – Pomaderris adnata, P. bodalla and P. walshii – have failed to reproduce for several years and are now found only in a few locations, each with a small number of plants.

Experimental trials recently revealed that to germinate, the seeds of these pomaderris species need exposure to hot-burning fires (or a hot oven). However they are now largely located in areas that seldom burn. This is important knowledge for conservation managers aiming to help wild populations persist.

Endangered sublime point pomaderris (Pomaderris adnata) requires high fire temperatures to germinate.
Jedda Lemmon /NSW DPIE, Saving our Species

Success is possible

A quarter of the species in the threatened plant index are orchids. Orchids make up 17% of plant species listed nationally as threatened, despite comprising just 6% of Australia’s total plant species.

The endangered coloured spider-orchid (Caladenia colorata) is pollinated only by a single thynnine wasp, and relies on a single species of mycorrhizal fungi to germinate in the wild.

Yet even for such a seemingly difficult species, conservation success is possible. In one project, scientists from the Royal Botanic Gardens Victoria, aided by volunteers, identified sites where the wasp was still naturally present. More than 800 spider orchid plants were then propagated in a lab using the correct symbiotic fungus, then planted at four sites. These populations are now considered to be self-sustaining.

In the case of Foote’s grevillea, a plant translocation program has established 500 plants at three new sites, dramatically improving the species’ long-term prospects.

Orchid flower
The coloured spider orchid, found in South Australia and Victoria, is endangered.
Noushka Reiter/Royal Botanic Gardens Victoria

But we aren’t doing enough

Both federal environment laws and the national threatened species strategy are under review. Submissions by research institutions and others have noted a lack of data, recovery actions and conservation funding for plants.

Our research found threatened plant populations at managed sites suffered declines of 60% on average, compared to 80% declines at unmanaged sites. This shows that while management is beneficial, it is not preventing overall declines.

New data on threatened species trends are added to the plant index each year, but many species are missing from the index because they aren’t being monitored.




Read more:
Australia’s threatened birds declined by 59% over the past 30 years


Monitoring of threatened species is undertaken by government and non-government groups, community groups, Indigenous organisations, citizen scientists, researchers and individuals. Without it, we have no idea if species are recovering or heading unnoticed towards extinction.

Woman measuring the height of a plant
Monitoring is essential to know if conservation actions are working.
Rebecca Dillon / WA Department of Biodiversity Conservation and Attractions

Australia has about 1,800 threatened species. Of these, 77% – or 1,342 species – are plants. However the index received monitoring data for only 10% of these plants, compared to 35% of threatened birds, which make up only 4% of threatened species.

If you’re keen to get involved in plant monitoring, it involves just a few simple steps:

  • find a local patch with a threatened plant species

  • revisit it once or twice a year to count the number of individuals in a consistent, well-defined area

  • use the same method and the same amount of effort each visit

  • take great care to not disturb the plant or its habitat when looking for it

  • contribute your data to the index.

Saving Australia’s flora

Australia must urgently change the way we prioritise conservation actions and enact environment laws, if we hope to prevent more plant extinctions.

Critical actions include stopping further habitat loss and more funding for recovery actions as well as extinction risk assessments. It is important that these assessments adhere to consistent criteria. This is something the common assessment method, agreed to by all states and territories, seeks to achieve.

Finally, more funding for research into the impacts of key threats (and how to manage them) will help ensure our unique flora are not lost forever.

Prof Hugh Possingham and Dr Ayesha Tulloch discuss the 2020 findings of the Threatened Plant Index.

CORRECTION: A previous version of this article incorrectly stated that reviews of federal environment laws and the threatened species strategy found a lack of data, recovery actions and conservation funding for plants. While those problems were identified in public submissions to the reviews, the reviews themselves are not yet finalised.The Conversation

Ayesha Tulloch, DECRA Research Fellow, University of Sydney; Elisa Bayraktarov, Postdoctoral Research Fellow in Conservation Biology, The University of Queensland; Hugh Possingham, Professor, The University of Queensland; Jaana Dielenberg, University Fellow, Charles Darwin University; Jennifer Silcock, Post-doctoral research fellow, The University of Queensland; Micha Victoria Jackson, Postdoctoral research fellow, The University of Queensland, and Nathalie Butt, Postdoctoral Fellow, The University of Queensland

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

Discovering New Flowering Plants Species While Bushwalking in Australia


The link below is to an article that looks at discovering new flowering plant species while bushwalking in Australia.

For more visit:
https://www.lifehacker.com.au/2020/09/find-new-species-of-daisies-on-your-aussie-bushwalks/

Food, tools and medicine: 5 native plants that illuminate deep Aboriginal knowledge



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Zena Cumpston, University of Melbourne

Over countless millennia, Aboriginal and Torres Strait Islander peoples have harnessed the tremendous potential of plants, ingeniously using them for medicines, nutrition, to express our culture and to develop innovative technologies.

But as I learn more about First Peoples’ plant knowledge, I’m also better understanding the broader Australian community’s failure to recognise the depth and breadth of our expertise.

Aboriginal people, our culture and deep knowledges are often seen as “in the past”, fixed and stagnant.

Damaging perceptions which cast us as lesser and posit us as a
homogenous peoples, who were limping towards inevitable extinction before
the arrival of a “superior” race, still abound. Such tropes deny our dynamic place in the present day, and our ability to continuously adapt and innovate.

Below I’ve listed five of my favourite indigenous plants and the multiple ways Aboriginal people used them, and continue to do so.




Read more:
To address the ecological crisis, Aboriginal peoples must be restored as custodians of Country


These plants are examples from my recent publication exploring Aboriginal plant use, and highlight our deep knowledge and holistic approaches to ecological management.

1. Spiny-headed mat-rush (Lomandra longifolia)

Spiny-headed mat-rush is a large tussocky plant found throughout southeastern Australia.

The Wurundjeri people particularly favour this plant for weaving cultural items such as necklaces, headbands, girdles, baskets, mats and bags for carrying foods, as well as for making technologies such as eel traps and hunting nets.

Spiny-headed mat-rush
Spiny-headed mat-rush.
Shutterstock

Its seeds are high in protein. They can be collected and pounded into a bread mix, with the core of the plant and the base of the leaves eaten as a vegetable.

Many diverse Aboriginal peoples use the roots to treat bites and stings. The caterpillars of several butterflies, such as the Symmomus Skipper, also rely on this plant for food and habitat.

2. Wallaby grass

There are around 30 types of wallaby grass in Australia. Native grasslands were once the most extensive habitat of Victoria’s western plains, but are now the most endangered plant community.

Wallaby grass
Wallaby grass.
John Tann/Wikimedia, CC BY

Grasslands provide food and habitat for a huge diversity of fauna, particularly birds, such as the peregrine falcon, whistling kite and Australian kestrels. Many animals, such as the legless lizard, little whip snake and fat-tailed dunnart, were once commonplace, but are now scarce in this endangered ecosystem.

Wallaby grass seeds make an excellent bread by pounding them into flour. The leaves and stem are also used to make cultural items, such as nets for fishing and hunting.

It’s also incredibly hardy – highly tolerant to frost, heat and drought, and requiring no fertilisers and little water. And it makes an excellent lawn, controlling erosion and weeds.

3. Bulbine lily (Bulbine bulbosa)

In summer, bulbine lily dies back to a dormant bulb, before re-shooting in late autumn. In spring, it displays vibrant yellow flowers.

Bulbine lily
Bulbine lily.
Shutterstock

Bulbine lilies can be found in all states except Western Australia, growing wild in tandem with milkmaids and chocolate lilies in the few areas of Victoria’s undisturbed remnant vegetation.

It’s considered the sweetest tasting of all edible root plants and is available year-round. You can find a plump, round, cream-coloured storage organ (a type of underground stem) under its stalk, which can be eaten after being roasted. Bulbine lily is also nutritious, a good source of calcium and iron.

4. Black kurrajong (Brachychiton populneus)

Aboriginal peoples from many diverse groups favour the fibrous kurrajong bark for making string for fishing lines, nets and bags, as well as body adornments such as headbands.

Flowers turn to fruit in the form of leathery pods. These pods contain highly nutritious yellow seeds, which contain around 18% protein and 25% fat, and high levels of magnesium and zinc.

Black kurrajong
Black kurrajong.
Luis Fernández García/Wikimedia, CC BY-SA

To eat the seeds, you first must remove toxic yellow hairs surrounding them. They can be eaten raw and roasted, and have a pleasantly nutty flavour. The young roots of this tree also make an excellent food source and can provide water.

5. Black sheoak (Allocasuarina littoralis)

Favouring dry conditions, black sheoak is native to Queensland, Tasmania, NSW and Victoria, and can grow up to eight metres high. It flowers in spring, with either rusty-brown spikes or red flowers that develop into cones.

Its seeds are an important food source for many native birds, including parrots and cockatoos.

Black Sheoak
Black sheoak.
John Robert McPherson/Wikimedia, CC BY-SA

Diverse groups of Aboriginal peoples use sheoaks for various purposes. The shoots and cones can be eaten, and sheoak wood can be used to fashion boomerangs, shields, clubs and other cultural implements because the wood is both strong and resists splitting and chipping.

In fact, the earliest evidence of boomerangs, found in the Wyrie Swamp in South Australia, were made from various sheoak species, and were dated at 10,000 years old.




Read more:
The art of healing: five medicinal plants used by Aboriginal Australians


The Conversation


Zena Cumpston, Research Fellow, University of Melbourne

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

‘Majestic, stunning, intriguing and bizarre’: New Guinea has 13,634 species of plants, and these are some of our favourites



Bulbophyllum alkmaarense: New Guinea is home to more than 2,400 species of native orchids.
Andre Schuiteman/CSIRO

Bruce Webber, CSIRO; Barry J Conn, University of Sydney, and Rodrigo Cámara-Leret, University of Zürich

Scientists have been interested in the flora of New Guinea since the 17th century, but formal knowledge of the tropical island’s diversity has remained limited.

To solve this mystery, our global team of 99 scientists from 56 institutions built the first ever expert-verified checklist to the region’s vascular plants (those with conductive tissue).

We found there are 13,634 formally described species of plants in New Guinea, of which a remarkable 68% are known to occur there and nowhere else. This richness trumps both Madagascar (11,488 species) and Borneo (11,165 species), making New Guinea the most floristically diverse island in the world.

From tarantula-like orchids to giant bananas, here we reveal some of the more mysterious plants on our checklist. Sadly, unsustainable logging and climate change threaten the conservation of many New Guinean species, and we highlight urgent solutions.




Read more:
People are ‘blind’ to plants, and that’s bad news for conservation


The majestic flora of New Guinea

New Guinea is a land of evocative contrasts. As the world’s largest tropical island – made up of Papua New Guinea to the east and two Indonesian provinces to the west – its biological diversity spans habitats from fringing mangroves to alpine grasslands.

The flora is diverse, filled with the majestic, stunning, intriguing and bizarre. However, very little is known about the conservation status of many species in New Guinea, which remains relatively unexplored by scientists.

The high hoop pine with thin branches and a full canopy
High hoop pines tower over forest canopy.
Wikimedia, CC BY

There are the few remaining forests of 60 metres high hoop pine (Araucaria cunninghamii) and klinkii pine (A. hunsteinii), that tower majestically up to 30 metres above the already tall rainforest canopy.

Figs, with their copious sap, are present in diverse forms, from small shrubs to vines, or large canopy trees.

And the strongly irritant black sap of the Semecarpus tree, a distant relative of the American poison ivy, causing severe dermatitis, is something naive botanists must learn to avoid!

Three panels showing different parts of Ryparosa amplifolia
Ryparosa amplifolia maintains an intimate association with ants via hollow stems and food bodies.
Bruce Webber, Author provided

Then there’s the Ryparosa amplifolia, a rainforest tree that provides swollen hollow stems for ant colonies to live inside. The tree also produces energy rich “food bodies” – granule-like structures on the leaves that mimic animal tissue and provide the ants with sustenance. In return, the ants act as bodyguards, chasing away insect herbivores, and leaf cleaners.

A giant banana tree with an umbrella-like canopy and a thick trunk towers in a rainforest
The giant banana tree holds the record of being the largest and tallest non-woody plant in the world.
Rodrigo Camara, Author provided

Some of our most popular foods were domesticated from New Guinea, including sugarcane and bananas. But the giant banana, Musa ingens is a a highlight in montane forests. Its leaves can stretch to a length of 5 metres, the tree can grow more than 20 metres tall, and its fruits are massive.

With more than 2,400 species of native orchid species, New Guinea is one of the most spectacular floral gardens in the world. It includes fascinating species such as Bulbophyllum nocturnum, which is the first and only known example of a night-flowering orchid, and Bulbophyllum tarantula, with appendages that resemble the iconic spider.

A close-up of a green orchid with pink blotches and furry leg-like bits
Bulbophyllum tarantula gets its name from its tarantula-like appearance.
Jan Meijvogel, Author provided

An uncertain future

Despite New Guinea’s seemingly high number of plant species, at least 3,000 species remain to be discovered and formally described. This estimate is based on the rate of description of new species in the past decades.

Much of New Guinea, particularly the Indonesian part, has been extremely poorly studied, with very few plant species collected. Even within Papua New Guinea, the distribution of many species is inadequately known. This means our findings should be viewed as a baseline upon which to prioritise further work.

The biggest impact on forest conservation is from logging, both clear-felling and degradation. As land is predominantly under customary ownership, addressing subsistence-related forest loss is a long-term challenge. Climate change adds yet further threats, including increased burning of degraded forest due to drier weather.

This means there’s a high risk of the world losing entire species before they are even known.

Looking down on the jungles of Papua New Guinea
Unsustainable logging and climate change are the biggest threats to the flora of New Guinea.
Shutterstock

To this end, in 2018 the governors of Indonesia’s two New Guinea provinces announced the Manokwari Declaration, a pledge to conserve 70% of forest cover for the western half of the island.

Reversing funding shortfalls and declining engagement

Our work builds on many decades of effort by plant collectors whose countless nights under leaking canvas, grass huts and bark shelters have led to thousands of plant discoveries.

Their stories are astounding. These fearless adventurers have sampled water plants by jumping from helicopters hovering low over Lake Tebera, swam in the Purari River rapids to haul a disabled dugout canoe full of botanists and cargo to safety, and have fallen into beds of stinging plants in the mountains of Wagau without subsequent access to pain relief.

Taxonomy – the discipline of identifying, classifying, and understanding relationships between plants – is the key to unlocking the value of this collecting effort.


A yellow flower with small brown spots and three appendages
Bulbophyllum nocturnum: the first known example of an orchid species in which flowers open after dark and close in the morning.
Jan Meijvogel, Author provided

But the discipline is suffering from global funding shortfalls and declining engagement. For instance, 40% of our co-authors on this work are 55 years or older.

Future opportunities for botanical research with local New Guineans at the helm is also vital – only 15% of the scientific publications on the New Guinean flora over the past 10 years involved local co-authors.

Improved collaboration between taxonomists, scientific institutions, governments and New Guinean scientific agencies could address these critical urgent priorities.

Undoubtedly, the conservation of New Guinea’s unique flora will be challenging and require work on many fronts that transcend single disciplines or institutions. From what we know already, a world of botanical surprises awaits in the last unknown.

After all, as 19th century naturalist J.B. Jukes wrote:

I know of no part of the world, the exploration of which is so flattering to the imagination, so likely to be fruitful in interesting results […] and altogether so well calculated to gratify the enlightened curiosity of an adventurous explorer, as the interior of New Guinea.




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From superheroes to the clitoris: 5 scientists tell the stories behind these species names


The Conversation


Bruce Webber, Principal Research Scientist, CSIRO; Barry J Conn, Researcher, University of Sydney, and Rodrigo Cámara-Leret, Researcher, University of Zürich

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

Click through the tragic stories of 119 species still struggling after Black Summer in this interactive (and how to help)



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Anthea Batsakis, The Conversation and Wes Mountain, The Conversation

This article is part of Flora, Fauna, Fire, a special project by The Conversation that tracks the recovery of Australia’s native plants and animals after last summer’s bushfire tragedy. Explore the project here and read more articles here.


Before the summer bushfires destroyed vast expanses of habitat, Australia was already in the midst of a biodiversity crisis. Now, some threatened species have been reduced to a handful of individuals – and extinctions are a real possibility.

The Kangaroo Island dunnart, a small marsupial, was listed as critically endangered before the bushfires. Then the inferno destroyed 95% of its habitat.

Prospects for the Banksia Montana mealybug are similarly grim. This flightless insect lives only on one species of critically endangered plant, at a high altitude national park in Western Australia. The fires destroyed 100% of the plant’s habitat.




Read more:
After the bushfires, we helped choose the animals and plants in most need. Here’s how we did it


And fewer than 100 western ground parrots remained in the wild before last summer, on Western Australia’s south coast. Last summer’s fires destroyed 40% of its habitat.

Fish, crayfish and some frogs are also struggling. After the fires, heavy rain washed ash, fire retardants and dirt into waterways. This can clog and damage gills, and reduces the water’s oxygen levels. Some animals are thought to have suffocated.

Here, dozens of experts tell the stories of the 119 species most in need of help after our Black Summer.

How can I help?

Recovery from Australia’s bushfire catastrophe will be a long road. If you want to help, here are a few places to start.

Donate

Australian Wildlife Conservancy

Bush Heritage Australia

WWF

Birdlife Australia

Also see this list of registered bushfire charities

Volunteer

Parks Victoria

NSW National Parks and Wildlife Service

Queensland Parks and Wildlife Service

Conservation Volunteers Australia

Landcare

The Conversation

Anthea Batsakis, Deputy Editor: Environment + Energy, The Conversation and Wes Mountain, Multimedia Editor, The Conversation

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

Summer bushfires: how are the plant and animal survivors 6 months on? We mapped their recovery


Anthea Batsakis, The Conversation; Nicole Hasham, The Conversation, and Wes Mountain, The Conversation

Australia roared into 2020 as a land on fire. The human and property loss was staggering, but the damage to nature was equally hard to fathom. By the end of the fire season 18.6 million hectares of land was destroyed.

So what’s become of animal and plant survivors in the months since?

Click through below to explore the impact Australia’s summer of fires had on an already drought-ravaged landscape and the work being done to rescue and recover habitats.


The Conversation

Anthea Batsakis, Deputy Editor: Environment + Energy, The Conversation; Nicole Hasham, Section Editor: Energy + Environment, The Conversation, and Wes Mountain, Multimedia Editor, The Conversation

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

After the bushfires, we helped choose the animals and plants in most need. Here’s how we did it



Daniel Marius/AAP

John Woinarski, Charles Darwin University; Dale Nimmo, Charles Sturt University; Rachael Gallagher, Macquarie University, and Sarah Legge, Australian National University

No other event in our lifetimes has brought such sudden, drastic loss to Australia’s biodiversity as the last bushfire season. Governments, researchers and conservationists have committed to the long road to recovery. But in those vast burnt landscapes, where do we start?

We are among the wildlife experts advising the federal government on bushfire recovery. Our role is to help determine the actions needed to stave off extinctions and help nature recover in the months and years ahead.

Our first step was to systematically determine which plant and animal species and ecosystems needed help most urgently. So let’s take a closer look at how we went about it.

Plants and animals are recovering from the fires, but some need a helping hand.
David Crosling/AAP

Sorting through the smoke

One way to work out how badly a species is affected by fire is to look at how much of its distribution – or the area in which it lives – was burnt.

This is done by overlapping fire maps with maps or records showing the species’ range. The greater the overlap, the higher the potential fire impact. But there are several complicating factors to consider:

1. Susceptibility: Species vary in how susceptible they are to fire. For instance, animals that move quickly – such as red-necked wallabies and the white-throated needletail – can escape an approaching fire. So too can animals that burrow deeply into the ground, such as wombats.

Less mobile animals, or those that live in vegetation, are more likely to die. We also considered post-fire recovery factors such as a species’ vulnerability to predators and reproductive rate.

The white-throated needle tail can escape the flames.
Tom Tarrant/Flickr

2. What we know: The quality of data on where species occur is patchy. For example, there are thousands of records for most of Australia’s 830 or so bird species. But there are very few reliable records for many of Australia’s 25,000-odd plant species and 320,000-odd invertebrate species.

So while we can estimate with some confidence how much of a crimson rosella’s distribution burned, the fire overlaps for less well-known species are much less certain.

3. The history of threats: The impact of fires on a region depends on the extent of other threats, such as drought and the region’s fire history. The time that elapses between fires can influence whether populations have recovered since the last fire.

For instance, some plants reproduce only from seed rather than resprouting. Fires in quick succession can kill regrowing plants before they’ve matured enough to produce seed. If that happens, species can become locally extinct.


Authors supplied

4. Fire severity: Some areas burn more intensely than others. High severity fires tend to kill more animals. They also incinerate vegetation and can scorch seeds lying in the soil.

Many Australian plant species are exquisitely adapted to regenerate and resprout after fire. But if a fire is intense enough, even these plants may not bounce back.

5. Already threatened?: Many species affected by these bushfires were already in trouble. For some, other threats had already diminished their numbers. Others were highly vulnerable because they were found only in very limited areas.

The bushfires brought many already threatened species closer to extinction. And other species previously considered secure are now threatened.




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Which species made the list?

With these issues in mind, and with contributions from many other experts, we compiled lists of plant, invertebrate and vertebrate species worst-affected by the 2019-20 fires. A similar assessment was undertaken for threatened ecosystems.

Some 471 plant, 213 invertebrate and 92 vertebrate species have been identified as a priority for interventions. Most had more than half their distribution burnt. Many have had more than 80% affected; some had 100% burnt.

The purple copper butterfly is listed as a priority for recovery efforts.
NSW Department of Planning, Industry and Environment

Priority invertebrates include land snails, freshwater crayfish, spiders, millipedes, beetles, dragonflies, grasshoppers, butterflies and bees. Many species had very small ranges.

For example, the inelegantly named Banksia montana mealybug – a tiny insect – existed only in the foliage of a few individuals of a single plant species in Western Australia’s Stirling Range, all of which were consumed by the recent fires.

Some priority plants, such as the Monga waratah, have persisted in Australia since their evolution prior to the break-up of the Gondwanan supercontinent about 140 million years ago. More than 50% of its current range burned, much at high severity. During recovery it is vulnerable to diseases such as phytophthora root rot.




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Some priority vertebrates have tiny distributions, such as the Mt Kaputar rock skink that lives only on rocky outcrops of Mt Kaputar near Narrabri, New South Wales. Others had large distributions that were extensively burnt, such as the yellow-bellied glider.

The priority lists include iconic species such as the koala, and species largely unknown to the public, such as the stocky galaxias, a fish that lives only in an alpine stream near Cooma in NSW.

Half the Monga waratah’s range burned in the fires.
Wikimedia

What’s being done

A federal government scheme is now allocating grants to projects that aim to help these species and ecosystems recover.

Affected species need immediate and longer-term actions to help them avoid extinction and recover. Critical actions common to all fire-affected species are:

  1. careful management of burnt areas so their recovery isn’t compromised by compounding pressures

  2. protecting unburnt areas from further fire and other threats, so they can support population recovery

  3. rapid surveys to identify where populations have survived. This is also the first step in ongoing monitoring to track recovery and the response to interventions.

Targeted control of feral predators, herbivores and weeds is also essential to the recovery of many priority species.

In some rare cases, plants or animals may need to be moved to areas where populations were reduced or wiped out. Captive breeding or seed collection can support this. Such restocking doesn’t just help recovery, it also spreads the risk of population loss in case of future fires.

Feral animals such as cats threaten native species in their recovery.
Hugh McGregor, Threatened Species Recovery Hub

Long road back

The COVID-19 pandemic has led to some challenges in implementing recovery actions. Like all of us, state agency staff, NGOs, academics and volunteer groups must abide by public health orders, which have in some cases limited what can be done and where.

But the restrictions may also have an upside. For instance, fewer vehicles on the roads might reduce roadkill of recovering wildlife.

As states ease restrictions, more groups will be able to continue the recovery process.




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Scientists find burnt, starving koalas weeks after the bushfires


As well as action on the ground, much planning and policy response is still required. Many fire-affected species must be added to threatened species lists to ensure they’re legally protected, and so remain the focus of conservation effort.

Fire management methods must be reviewed to reduce the chance of future catastrophic fires, and to make sure the protection of biodiversity assets is considered in fire management planning and suppression.

Last bushfire season inflicted deep wounds on our biodiversity. We need to deal with that injury. We must also learn from it, so we can respond swiftly and effectively to future ecological disasters.


Many species experts and state/territory agency representatives contributed to the analyses of priority species. Staff from the Department of Agriculture, Water and the Environment (especially the Environmental Resources Information Network (Geospatial and Information Analytics Branch), the Protected Species and Communities Branch and the Threatened Species Commissioner’s Office) and Expert Panel members also contributed significantly to this work.The Conversation

John Woinarski, Professor (conservation biology), Charles Darwin University; Dale Nimmo, Associate Professor in Ecology, Charles Sturt University; Rachael Gallagher, Senior Lecturer/ARC DECRA Fellow, Macquarie University, and Sarah Legge, Professor, Australian National University

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

Climate explained: why higher carbon dioxide levels aren’t good news, even if some plants grow faster



Shutterstock

Sebastian Leuzinger, Auckland University of Technology

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz

If carbon dioxide levels were to double, how much increase in plant growth would this cause? How much of the world’s deserts would disappear due to plants’ increased drought tolerance in a high carbon dioxide environment?

Compared to pre-industrial levels, the concentration of carbon dioxide (CO₂) in the atmosphere will have doubled in about 20 to 30 years, depending on how much CO₂ we emit over the coming years. More CO₂ generally leads to higher rates of photosynthesis and less water consumption in plants.

At first sight, it seems more CO₂ can only be beneficial to plants, but things are a lot more complex than that.




Read more:
Climate explained: why plants don’t simply grow faster with more carbon dioxide in air


Let’s look at the first part of the question.

Some plants do grow faster under elevated levels of atmospheric CO₂, but this happens mostly in crops and young trees, and generally not in mature forests.

Even if plants grew twice as fast under doubled CO₂ levels, it would not mean they strip twice as much CO₂ from the atmosphere. Plants take carbon from the atmosphere as they grow, but that carbon is going straight back via natural decomposition when plants die or when they are harvested and consumed.

At best, you might be mowing your lawn twice as often or harvesting your plantation forests earlier.

The most important aspect is how long the carbon stays locked away from the atmosphere – and this is where we have to make a clear distinction between increased carbon flux (faster growth) or an increasing carbon pool (actual carbon sequestration). Your bank account is a useful analogy to illustrate this difference: fluxes are transfers, pools are balances.




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Climate explained: why your backyard lawn doesn’t help reduce carbon dioxide in the atmosphere


The global carbon budget

Of the almost 10 billion tonnes (gigatonnes, or Gt) of carbon we emit every year through the burning of fossil fuels, only about half accumulates in the atmosphere. Around a quarter ends up in the ocean (about 2.4 Gt), and the remainder (about 3 Gt) is thought to be taken up by terrestrial plants.

While the ocean and the atmospheric sinks are relatively easy to quantify, the terrestrial sink isn’t. In fact, the 3 Gt can be thought of more as an unaccounted residual. Ultimately, the emitted carbon needs to go somewhere, and if it isn’t the ocean or the atmosphere, it must be the land.

So yes, the terrestrial system takes up a substantial proportion of the carbon we emit, but the attribution of this sink to elevated levels of CO₂ is difficult. This is because many other factors may contribute to the land carbon sink: rising temperature, increased use of fertilisers and atmospheric nitrogen deposition, changed land management (including land abandonment), and changes in species composition.

Current estimates assign about a quarter of this land sink to elevated levels of CO₂, but estimates are very uncertain.

In summary, rising CO₂ leads to faster plant growth – sometimes. And this increased growth only partly contributes to sequestering carbon from the atmosphere. The important questions are how long this carbon is locked away from the atmosphere, and how much longer the currently observed land sink will continue.




Read more:
Climate explained: how different crops or trees help strip carbon dioxide from the air


The second part of the question refers to a side-effect of rising levels of CO₂ in the air: the fact that it enables plants to save water.

Plants regulate the exchange of carbon dioxide and water vapour by opening or closing small pores, called stomata, on the surface of their leaves. Under higher concentrations of CO₂, they can reduce the opening of these pores, and that in turn means they lose less water.

This alleviates drought stress in already dry areas. But again, the issue is more complex because CO₂ is not the only parameter that changes. Dry areas also get warmer, which means that more water evaporates and this often compensates for the water-saving effect.

Overall, rising CO₂ has contributed to some degree to the greening of Earth, but it is likely that this trend will not continue under the much more complex combination of global change drivers, particularly in arid regions.The Conversation

Sebastian Leuzinger, Professor, Auckland University of Technology

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

These plants and animals are now flourishing as life creeps back after bushfires


Flickr

Kathryn Teare Ada Lambert, University of New England

As the east coast bushfire crisis finally abates, it’s easy to see nothing but loss: more than 11 million hectares of charcoal and ash, and more than a billion dead animals.

But it is heartening to remember that bushfire can be a boon to some plants and animals. We’re already seeing fresh green shoots as plants and trees resprout. Beetles and other insects are making short work of animal carcasses; they will soon be followed by the birds which feed on them.

Australia’s worsening fire regimes are challenging even these tolerant species. But let’s take a look at exactly how life is returning to our forests now, and what to expect in coming months.

Life is returning to fire-ravaged landscapes.
Flickr, CC BY

The science of resprouting

Of course, bushfires kill innumerous trees – but many do survive. Most of us are familiar with the image of bright green sprouts shooting from the trunks and branches of trees such as eucalypts. But how do they revive so quickly?

The secret is a protected “bud bank” which lies behind thick bark, protected from the flames. These “epicormic” buds produce leaves, which enables the tree to photosynthesise – create sugar from the sun so the tree can survive.

Under normal conditions, hormones from shoots higher in the tree suppress these buds. But when the tree loses canopy leaves due to fire, drought or insect attack, the hormone levels drop, allowing the buds to sprout.

Insect influx

This summer’s fires left in their wake a mass of decaying animal carcasses, logs and tree trunks. While such a loss can be devastating for many species – particularly those that were already vulnerable – many insects thrive in these conditions.

For example, flies lay eggs in the animal carcasses; when the maggots hatch, the rotting flesh provides an ample food source. This process helps break down the animal’s body – reducing bacteria, disease and bad smells. Flies are important decomposers and their increased numbers also provide food for birds, reptiles and other species.




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Similarly, beetles such as the grey furrowed rosechafer, whose grubs feed on decaying logs and tree trunks, add nutrients to the soil when they defecate which helps plants grow again.

Insects also benefit from the mass of new leaves on trunks and branches. For example, native psyllids – an insect similar to aphids – feed on the sap from leaves and so thrive on the fresh growth.

Animal carcasses are a sad consequence of bushfire, but provide a boon to some insect species.
Sean Davey/AAP

Then come the birds

Once insects start to move back into an area from forested areas nearby, the birds that eat them will follow.

An increase in psyllids encourages honeyeaters – such as bell miners and noisy miners – to return. These birds are considered pests.

A CSIRO study after bushfires in Victoria’s East Gippsland in 1983 found several native bird species – flame and scarlet robins, the buff-rumped thornbill and superb fairy-wren – increased quickly to levels greater than before fire. As shrubs in the understorey regrow, other species will move in, slowly increasing biodiversity.




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Not all weeds are villains. After a fire, some plants – even weeds – can be better than none


Since the recent bushfire in woodland near Moonbi in New South Wales, numerous bird species have returned. On a visit over this past weekend, I observed currawongs landing in the canopy, saw fairy wrens darting in and out of foliage sprouting from the ground, and heard peep wrens in tufts of foliage on bark and high branches.

Honeyeaters moved between burnt and intact trees on the edge of the blackened forest and butterflies visited new plants flowering after recent rain.

The presence of the currawong, while a pest species, shows birdlife is returning to the bush.
Flickr, CC BY

Weeds can help

Weeds usually benefit when fire opens up the tree canopy and lets in light. While this has a downside – preventing native plants from regenerating – weeds can also provide cover for native animal species.

A study I co-authored in 2018 found highly invasive Lantana camara provided habitat for small mammals such as the brown rat in some forests. Mammal numbers in areas where lantana was present were greater than where it was absent.

Lantana often grows quickly after fire due to the increase in light and its ability to suppress other plant growth.

Lantana provides cover for animal species.
Flickr, CC BY

Is there hope for threatened species?

Generalist species – those that thrive in a variety of environments – can adapt to burnt forest. But specialist species need particular features of an ecosystem to survive, and are far less resilient.

The critically endangered Leadbeater’s possum lives only in small pockets of forest in Victoria.

It requires large fires to create a specific habitat: big dead trees provide hollows for shelter and nesting, and insects feeding on burnt wood and carcasses provide a food source.

But for the Leadbeater’s possum to benefit from the fire regime, bushfires should be infrequent – perhaps every 75 years – allowing time for the forest to grow back. If fires are too frequent, larger trees will not have time to establish and hollows will not be created, causing the species’ numbers to decline.

Similarly in NSW, at least 50% and up to 80% of the habitat of threatened species such as the vulnerable rufous scrub-bird was burnt in the recent fires, an environmental department analysis found.

Looking ahead

Only time will tell whether biodiversity in these areas is forever damaged, or will return to its former state.

Large fires may benefit some native species but they also provide food and shelter for predatory species, such as feral cats and foxes. The newly open forest leaves many native mammals exposed, changing the foodweb, or feeding relationships, in an ecosystem.

This means we may see a change in the types of birds, reptiles and mammals found in forests after the fires. And if these areas don’t eventually return to their pre-fire state, these environments may be changed forever – and extinctions will be imminent.




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The Conversation


Kathryn Teare Ada Lambert, Adjunct Lecturer/ Ecologist, University of New England

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