Pulling out weeds is the best thing you can do to help nature recover from the fires



Australians are keen to help nature recover after a season of devastating bushfires.
Darren England/AAP

Don Driscoll, Deakin University

Many Australians feel compelled to help our damaged wildlife after this season’s terrible bushfires. Suggested actions have included donating money, leaving water out for thirsty animals, and learning how to help the injured. But there is an equally, if not more, important way to assist: weeding.

An army of volunteers is needed to help land owners with judicious weed removal. This will help burnt habitats recover more quickly, providing expanded, healthy habitat for native fauna.

Other emergency responses, such as culling feral animals and dropping emergency food from aeroplanes, are obviously jobs for specialists. But volunteer weeding does not require any prior expertise – just a willingness to get your hands dirty and take your lead from those in the know.

Volunteer weeding will help burnt habitats recover more quickly.
Silje Polland/Flickr

Why is weeding so critical?

The recent bushfires burned many areas in national parks and reserves which were infested with weeds. Some weeds are killed in a blaze, but fire also stimulates their seed banks to germinate.

Weed seedlings will spring up en masse and establish dense stands that out-compete native plants by blocking access to sunlight. Native seedlings will die without setting seed, wasting this chance for them to recover and to provide habitat for a diverse range of native species.




Read more:
Many of our plants and animals have adapted to fires, but now the fires are changing


This mass weed germination is also an opportunity to improve the outlook for biodiversity. With a coordinated volunteer effort, these weeds can be taken out before they seed – leaving only a residual seed bank with no adult weeds to create more seed and creating space for native plants to flourish.

With follow-up weeding, we can leave our national parks and reserves – and even bushland on farms – in a better state than they were before the fires.

Bush regeneration groups are well placed to restore forests after fire, but need volunteers.
Flickr

Weeding works

In January 1994, fire burned most of Lane Cove National Park in Sydney. Within a few months of the fire, volunteer bush regeneration groups were set up to help tackle regenerating weeds.

Their efforts eradicated weeds from areas where the problem previously seemed intractable and prevented further weed expansion. Key to success in this case was the provision of funding for coordination, an engaged community which produced passionate volunteers and enough resources to train them.




Read more:
Conservation scientists are grieving after the bushfires — but we must not give up


Following recent fires in the Victorian high country, volunteers will be critical to controlling weeds, particularly broom (Scotch broom and related species), which occurs throughout fire-affected areas .

Fire typically kills these woody shrubs but also stimulates seed germination. Without intervention, broom will form dense stands which out-compete native plant species .

However, swift action now can prevent this. Mass germination reduces the broom’s seedbank to as low as 8% of pre-fire levels, and around half of the remaining seeds die each year. Further, broom usually takes three years to flower and replenish its seedbank. So with no new seeds being produced and the seedbank low and shrinking, this three-year window offers an important opportunity to restore previously infested areas.

Scotch broom, a native shrub of Western Europe, has infested vast swathes of Australia.
Gunter Maywald-CSIRO/Wikimedia

Parks Victoria took up this opportunity after the 2003 fires in the Alpine National Park. They rallied agencies, natural resource management groups and local landholders to sweep up broom . Herbicide trials at that time revealed that to get the best outcome for their money, it was critical to spray broom seedlings early, within the first year and a half.

Broom management also needs to use a range of approaches, including using volunteers to spread a biological control agent.

Plenty of work to do

Parks Victoria continue to engage community groups in park management and will coordinate fire response actions when parks are safe to enter. Similar programs can be found in New South Wales, Western Australia, South Australia, Queensland, Tasmania, the Northern Territory, and the ACT.

A wide range of weeds expand after fire and warrant a rapid response. They include lantana, bitou bush, and
blackberry.




Read more:
Yes, native plants can flourish after bushfire. But there’s only so much hardship they can take


Managing weeds after fire is currently a high priority at many sites. At the edges of the World Heritage Gondwana rainforests of southwest Queensland and northern and central NSW, there is a window to more effectively control lantana. In many forested areas in NSW, Victoria and South Australia, fire has created an opportunity to address important weed problems.

State government agencies have the mapping capacity to locate these places. Hopefully they can make these resources easy for the public to access soon, so community groups can self-organise and connect with park managers.

A koala badly injured during the Canberra bushfires before it was returned to the wild.
ALAN PORRIT/AAP

All this needs money

Emergency funding is now essential to enable community-based weed control programs at the scale needed to have a substantial impact. Specifically, funding is needed for group coordinators, trainers and equipment.

While emergency work is needed to control regenerating weeds in the next 6-18 months, ongoing work is needed after that to consolidate success and prevent reinfestations from the small, but still present, seed bank.

Ongoing government funding is needed to enable this work, and prepare for a similar response to the next mega-fires.

Want to act immediately?

You can volunteer to do your bit for fire recovery right now. In addition to state-agency volunteer websites, there are many existing park care, bush care and “friends of” groups coordinated by local governments. They’re waiting for you to join so they can start planning the restoration task in fire-affected areas.

Contact them directly or register your interest with the Australian Association of Bush Regenerators who can link you with the appropriate organisations.




Read more:
You can leave water out for wildlife without attracting mosquitoes, if you take a few precautions


If we do nothing now, the quality of our national parks will decline as weeds take over and native species are lost. But if you channel your fire-response energy and commitment to help manage weeds, our national parks could come out in front from this climate-change induced calamity.

By all means, rescue an injured koala. But by pulling out weeds, you could also help rescue a whole ecosystem.


Dr Tein McDonald, president of the Australian Association of Bush Regenerators, contributed to this article.The Conversation

Don Driscoll, Professor in Terrestrial Ecology, Deakin University

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

How invasive weeds can make wildfires hotter and more frequent



File 20171218 17860 8i8ehc.jpg?ixlib=rb 1.1
Mixed grill: burning combinations of invasive and native plants helps us understand how invasive plants make fires hotter and more likely.
Sarah Wyse, CC BY-ND

Tim Curran, Lincoln University, New Zealand; George Perry, and Sarah Wyse

Over the past year the global media has been full of reports of catastrophic fires in California, the Mediterranean, Chile and elsewhere. One suggested reason for increases in catastrophic wildfires has been human-induced climate change. Higher temperatures, drier weather and windier conditions all increase the impact of fires.

While climate change indeed raises the risk of wildfires, our research shows that another way humans can change patterns of fire activity is by introducing flammable plants to new environments.


Read more: How will Canada manage its wildfires in the future?


Plantations of highly flammable exotic species, such as pines and eucalypts, probably helped to fuel the recent catastrophic fires in Portugal and in Chile. In arid regions, such as parts of the US southwest, the introduction of exotic grasses has transformed shrublands, as fires increase in severity.

Invasive plants and fire

How do invasive plants change fire patterns? We burned species mixtures (aka “mixed grills”) on our plant barbecue to help find out.

Invasive plants are responsible for changing the patterns of fire activity in many ecosystems around the world. In particular, invasive species can lead to hotter and more frequent fires.

Invasive plants can also reduce fire frequency and fire intensity, but there are fewer examples of this occurring worldwide.

One of the main ways flammable invasive plants can have long-lasting impacts on an ecosystem comes from positive fire-vegetation feedbacks. Such feedbacks can occur when a flammable weed invades a less fire-prone ecosystem. By changing the available fuel the invader makes fires more likely and often hotter.

If the invading species has characteristics that allow it to outcompete native species after a fire, then it will further dominate the ecosystem. Such traits include thick bark, the ability to resprout following fire, or seeds that survive burning. This invasion will likely lead to more fires, changing the species composition and function of the ecosystem in a “fire begets fire” cycle. Extreme examples of this dynamic are where flammable grasses or shrubs invade forests, leading to loss of the forest ecosystems.

Mixed grills

We wanted to understand how invasive plants interact with other species when burned in combination. To explore the mechanisms underpinning such feedbacks, we examined how invasive plants might change the nature of a fire when burned together with native species.

We collected 70cm shoots of four globally invasive species (of both high and low flammability) and burned them in pairwise combinations with New Zealand native trees and shrubs to determine which characteristics of a fire could be attributed to the invasive plants.

Samples of Hakea sericea (foreground) and Kunzea robusta (rear) arranged on the grill of our plant barbecue.
Sarah Wyse, CC BY-ND

We found that overall flammability was largely driven by the most flammable species in the mixture, showing how highly flammable weeds could set in motion fire-vegetation feedbacks.

We established that a greater difference in flammability between the two species led to a larger influence of the more flammable species on overall flammability. This outcome suggests weeds that are much more flammable than the invaded community can have larger impacts on fire patterns.

Importantly, we also showed the influence of the highly flammable species was independent of its biomass, meaning highly flammable weeds may impact community flammability even at low abundances.

When we looked closer at the different components of flammability (combustibility, ignitability, consumability and sustainability) we found some important nuances in our results.

While the maximum temperature reached in our burns (combustibility) and the ignition speed (ignitability) were both most influenced by the more flammable species, consumability (the amount of biomass burned) and sustainability (how long the fire burns) were equally influenced by both the more flammable and less flammable species.

In short, more flammable weeds will cause a fire to ignite more quickly and burn hotter.

However, less flammable species can reduce the duration of a fire compared to when a more flammable species is burnt alone. These results could have important ecological implications, as the longer a fire burns the more likely it is to kill plants: low-flammability plants could reduce this impact.

Measuring how long a fire burns on our plant barbecue.
Tom Etherington, CC BY-ND

Managing weeds to reduce fire impacts

Even low abundances of highly flammable invasive weeds could set in motion positive fire-vegetation feedbacks that lead to drastic changes to ecosystems. If this result holds when our shoot-scale experiments are repeated using field trials, then land managers should work quickly to remove even small infestations of highly flammable species, such as gorse (Ulex europaeus) and prickly hakea (Hakea sericea).

Conversely, the role of low flammability plants in extinguishing fires further supports the suggestion that the strategic planting of such species across the landscape as “green firebreaks” could be a useful fire management tool.

The ConversationIn any case, our “mixed grill” study further highlights the role of exotic plants in fuelling hotter wildfires.

Tim Curran, Senior Lecturer in Ecology, Lincoln University, New Zealand; George Perry, Professor, School of Environment, and Sarah Wyse, Early Career Research Fellow, The Royal Botanic Gardens, Kew and Research Fellow, School of Environment

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

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


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

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

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

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

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

Shrub invasion

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

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

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

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

What’s going on?

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

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

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

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

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

Hopping to it

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

The Dingo Fence.
Ben Moore

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

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

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

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

Fieldwork in the Strzelecki Desert.
Dr Ben Moore

Going wild again

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

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

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

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

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

The Conversation

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

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

Blackbutt Reserve


Kevin's Daily Photo, Video, Quote or Link

Since I was unable to visit Gap Creek Falls the other day, I decided I might pop in to have a look at the new animal enclosures at Blackbutt Reserve near Newcastle. I will say straight off the bat that I do have something of a prejudice against Blackbutt Reserve, as I see the place as nothing like a natural bush setting, it being far too ‘corrupted’ by human activity, weeds and the like. Having said that it is a good place for a family or group outing/event. It certainly has its place, but it is not a true nature reserve (in my opinion).

Visitor Centre

ABOVE: Visitor Centre

I do think that some well designed animal and bird enclosures at Blackbutt could lift the value of the reserve dramatically and make it a really great place for families, especially young families. There are opportunities for educational visits for kids, possible environmental…

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Antarctica: Weed Invasion Threat


The article below reports on the threat to Antarctica posed by weeds brought in by human visitors. This is a threat that will continue to grow with climate change.

See also:
http://www.nytimes.com/2012/03/20/opinion/seeding-the-southern-continent.html

Antarctica: Invasion of the Weeds and Pests


The link below is to an article reporting on the invasion of weeds and pests in Antarctica. The threat is growing with climate change and human visitation.

For more visit:
http://www.bbc.co.uk/news/science-environment-17258799

India: Kaziranga National Park – The Rhinoceros now Threatened by Weeds


The link below is to an article about the threat posed to Rhinos in India by the weed Mimosa diplotricha. According to the article poaching is somewhat under control (poaching for horns), but now the Rhino is threatened by the rapidly spreading Mimosa weed that is smothering out grasses that provide feed for the Rhino.

For more visit:
http://ipsnews.net/news.asp?idnews=106803